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1. A core of functional complementary bacteria infects oysters in Pacific Oyster Mortality Syndrome

Author

Camille Clerissi, Xing Luo, Aude Lucasson, Shogofa Mortaza, Julien de Lorgeril, Eve Toulza, Bruno Petton, Jean-Michel Escoubas, Lionel Dégremont, Yannick Gueguen, Delphine Destoumieux-Garzόn, Annick Jacq, and Guillaume Mitta

Subjects
Metabarcoding, Metatranscriptomics, Pathobiota, Metabolism, Resource partitioning, Veterinary medicine, SF600-1100, Microbiology, QR1-502
Abstract

Abstract Background The Pacific oyster Crassostrea gigas is one of the main cultivated invertebrate species worldwide. Since 2008, oyster juveniles have been confronted with a lethal syndrome known as the Pacific Oyster Mortality Syndrome (POMS). POMS is a polymicrobial disease initiated by a primary infection with the herpesvirus OsHV-1 µVar that creates an oyster immunocompromised state and evolves towards a secondary fatal bacteremia. Results In the present article, we describe the implementation of an unprecedented combination of metabarcoding and metatranscriptomic approaches to show that the sequence of events in POMS pathogenesis is conserved across infectious environments. We also identified a core bacterial consortium which, together with OsHV-1 µVar, forms the POMS pathobiota. This bacterial consortium is characterized by high transcriptional activities and complementary metabolic functions to exploit host’s resources. A significant metabolic specificity was highlighted at the bacterial genus level, suggesting low competition for nutrients between members of the core bacteria. Conclusions Lack of metabolic competition between the core bacteria might favor complementary colonization of host tissues and contribute to the conservation of the POMS pathobiota across distinct infectious environments.

Published
2023
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2. Early life microbial exposures shape the Crassostrea gigas immune system for lifelong and intergenerational disease protection

Author

Manon Fallet, Caroline Montagnani, Bruno Petton, Luc Dantan, Julien de Lorgeril, Sébastien Comarmond, Cristian Chaparro, Eve Toulza, Simon Boitard, Jean-Michel Escoubas, Agnès Vergnes, Jacqueline Le Grand, Ingo Bulla, Yannick Gueguen, Jérémie Vidal-Dupiol, Christoph Grunau, Guillaume Mitta, and Céline Cosseau

Subjects
Oyster, Aquaculture, Microbiota, Innate immune shaping, Epigenetic, DNA methylation, Microbial ecology, QR100-130
Abstract

Abstract Background The interaction of organisms with their surrounding microbial communities influences many biological processes, a notable example of which is the shaping of the immune system in early life. In the Pacific oyster, Crassostrea gigas, the role of the environmental microbial community on immune system maturation — and, importantly, protection from infectious disease — is still an open question. Results Here, we demonstrate that early life microbial exposure durably improves oyster survival when challenged with the pathogen causing Pacific oyster mortality syndrome (POMS), both in the exposed generation and in the subsequent one. Combining microbiota, transcriptomic, genetic, and epigenetic analyses, we show that the microbial exposure induced changes in epigenetic marks and a reprogramming of immune gene expression leading to long-term and intergenerational immune protection against POMS. Conclusions We anticipate that this protection likely extends to additional pathogens and may prove to be an important new strategy for safeguarding oyster aquaculture efforts from infectious disease. tag the videobyte/videoabstract in this section Video Abstract

Published
2022
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3. Differential basal expression of immune genes confers Crassostrea gigas resistance to Pacific oyster mortality syndrome

Author

Julien de Lorgeril, Bruno Petton, Aude Lucasson, Valérie Perez, Pierre-Louis Stenger, Lionel Dégremont, Caroline Montagnani, Jean-Michel Escoubas, Philippe Haffner, Jean-François Allienne, Marc Leroy, Franck Lagarde, Jérémie Vidal-Dupiol, Yannick Gueguen, and Guillaume Mitta

Subjects
Pacific oyster, Oyster disease, Resistance, OsHV-1, Antiviral molecular pathways, Invertebrate immunity, Biotechnology, TP248.13-248.65, Genetics, QH426-470
Abstract

Abstract Background As a major threat to the oyster industry, Pacific Oyster Mortality Syndrome (POMS) is a polymicrobial disease affecting the main oyster species farmed across the world. POMS affects oyster juveniles and became panzootic this last decade, but POMS resistance in some oyster genotypes has emerged. While we know some genetic loci associated with resistance, the underlying mechanisms remained uncharacterized. So, we developed a comparative transcriptomic approach using basal gene expression profiles between different oyster biparental families with contrasted phenotypes when confronted to POMS (resistant or susceptible). Results We showed that POMS resistant oysters show differential expression of genes involved in stress responses, protein modifications, maintenance of DNA integrity and repair, and immune and antiviral pathways. We found similarities and clear differences among different molecular pathways in the different resistant families. These results suggest that the resistance process is polygenic and partially varies according to the oyster genotype. Conclusions We found differences in basal expression levels of genes related to TLR-NFκB, JAK-STAT and STING-RLR pathways. These differences could explain the best antiviral response, as well as the robustness of resistant oysters when confronted to POMS. As some of these genes represent valuable candidates for selective breeding, we propose future studies should further examine their function.

Published
2020
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4. Immune-suppression by OsHV-1 viral infection causes fatal bacteraemia in Pacific oysters

Author

Julien de Lorgeril, Aude Lucasson, Bruno Petton, Eve Toulza, Caroline Montagnani, Camille Clerissi, Jeremie Vidal-Dupiol, Cristian Chaparro, Richard Galinier, Jean-Michel Escoubas, Philippe Haffner, Lionel Dégremont, Guillaume M. Charrière, Maxime Lafont, Abigaïl Delort, Agnès Vergnes, Marlène Chiarello, Nicole Faury, Tristan Rubio, Marc A. Leroy, Adeline Pérignon, Denis Régler, Benjamin Morga, Marianne Alunno-Bruscia, Pierre Boudry, Frédérique Le Roux, Delphine Destoumieux-Garzόn, Yannick Gueguen, and Guillaume Mitta

Subjects
Science
Abstract

Pacific oyster mortality syndrome is a poorly understood cause of mortality in commercially important oyster species. Here, the authors use multiple infection experiments to show that the syndrome is caused by sequential infection by herpesvirus and opportunistic bacteria.

Published
2018
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5. Contribution of Viral Genomic Diversity to Oyster Susceptibility in the Pacific Oyster Mortality Syndrome

Author

Jean Delmotte, Cristian Chaparro, Richard Galinier, Julien de Lorgeril, Bruno Petton, Pierre-Louis Stenger, Jeremie Vidal-Dupiol, Delphine Destoumieux-Garzon, Yannick Gueguen, Caroline Montagnani, Jean-Michel Escoubas, and Guillaume Mitta

Subjects
Crassostrea gigas, herpesvirus diversity, genotype-genotype interactions, oyster genetic background, viral populations, Microbiology, QR1-502
Abstract

Juvenile Pacific oysters (Crassostrea gigas) are subjected to recurrent episodes of mass mortalities that constitute a threat for the oyster industry. This mortality syndrome named “Pacific Oyster Mortality Syndrome” (POMS) is a polymicrobial disease whose pathogenesis is initiated by a primary infection by a variant of an Ostreid herpes virus named OsHV-1 μVar. The characterization of the OsHV-1 genome during different disease outbreaks occurring in different geographic areas has revealed the existence of a genomic diversity for OsHV-1 μVar. However, the biological significance of this diversity is still poorly understood. To go further in understanding the consequences of OsHV-1 diversity on POMS, we challenged five biparental families of oysters to two different infectious environments on the French coasts (Atlantic and Mediterranean). We observed that the susceptibility to POMS can be different among families within the same environment but also for the same family between the two environments. Viral diversity analysis revealed that Atlantic and Mediterranean POMS are caused by two distinct viral populations. Moreover, we observed that different oyster families are infected by distinct viral populations within a same infectious environment. Altogether these results suggest that the co-evolutionary processes at play between OsHV-1 μVar and oyster populations have selected a viral diversity that could facilitate the infection process and the transmission in oyster populations. These new data must be taken into account in the development of novel selective breeding programs better adapted to the oyster culture environment.

Published
2020
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6. A Sustained Immune Response Supports Long-Term Antiviral Immune Priming in the Pacific Oyster, Crassostrea gigas

Author

Maxime Lafont, Agnès Vergnes, Jeremie Vidal-Dupiol, Julien de Lorgeril, Yannick Gueguen, Philippe Haffner, Bruno Petton, Cristian Chaparro, Celia Barrachina, Delphine Destoumieux-Garzon, Guillaume Mitta, Benjamin Gourbal, and Caroline Montagnani

Subjects
innate immunity, priming, OsHV-1, antiviral response, immune memory, oyster, Microbiology, QR1-502
Abstract

ABSTRACT Over the last decade, innate immune priming has been evidenced in many invertebrate phyla. If mechanistic models have been proposed, molecular studies aiming to substantiate these models have remained scarce. We reveal here the transcriptional signature associated with immune priming in the oyster Crassostrea gigas. Oysters were fully protected against Ostreid herpesvirus 1 (OsHV-1), a major oyster pathogen, after priming with poly(I·C), which mimics viral double-stranded RNA. Global analysis through RNA sequencing of oyster and viral genes after immune priming and viral infection revealed that poly(I·C) induces a strong antiviral response that impairs OsHV-1 replication. Protection is based on a sustained upregulation of immune genes, notably genes involved in the interferon pathway and apoptosis, which control subsequent viral infection. This persistent antiviral alert state remains active over 4 months and supports antiviral protection in the long term. This acquired resistance mechanism reinforces the molecular foundations of the sustained response model of immune priming. It further opens the way to applications (pseudovaccination) to cope with a recurrent disease that causes dramatic economic losses in the shellfish farming industry worldwide. IMPORTANCE In the last decade, important discoveries have shown that resistance to reinfection can be achieved without a functional adaptive immune system, introducing the concept of innate immune memory in invertebrates. However, this field has been constrained by the limited number of molecular mechanisms evidenced to support these phenomena. Taking advantage of an invertebrate species, the Pacific oyster (Crassostrea gigas), in which we evidenced one of the longest and most effective periods of protection against viral infection observed in an invertebrate, we provide the first comprehensive transcriptomic analysis of antiviral innate immune priming. We show that priming with poly(I·C) induced a massive upregulation of immune-related genes, which control subsequent viral infection, and it was maintained for over 4 months after priming. This acquired resistant mechanism reinforces the molecular foundations of the sustained response model of immune priming. It opens the way to pseudovaccination to prevent the recurrent diseases that currently afflict economically or ecologically important invertebrates.

Published
2020
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7. Microbiota Composition and Evenness Predict Survival Rate of Oysters Confronted to Pacific Oyster Mortality Syndrome

Author

Camille Clerissi, Julien de Lorgeril, Bruno Petton, Aude Lucasson, Jean-Michel Escoubas, Yannick Gueguen, Lionel Dégremont, Guillaume Mitta, and Eve Toulza

Subjects
holobiont, microbiome, metabarcoding, fitness, bacteria, Microbiology, QR1-502
Abstract

Pacific Oyster Mortality Syndrome (POMS) affects Crassostrea gigas oysters worldwide and causes important economic losses. Disease dynamic was recently deciphered and revealed a multiple and progressive infection caused by the Ostreid herpesvirus OsHV-1 μVar, triggering an immunosuppression followed by microbiota destabilization and bacteraemia by opportunistic bacterial pathogens. However, it remains unknown if microbiota might participate to protect oysters against POMS, and if microbiota characteristics might be predictive of oyster mortalities. To tackle this issue, we transferred full-sib progenies of resistant and susceptible oyster families from hatchery to the field during a period in favor of POMS. After 5 days of transplantation, oysters from each family were either sampled for individual microbiota analyses using 16S rRNA gene-metabarcoding or transferred into facilities to record their survival using controlled condition. As expected, all oysters from susceptible families died, and all oysters from the resistant family survived. Quantification of OsHV-1 and bacteria showed that 5 days of transplantation were long enough to contaminate oysters by POMS, but not for entering the pathogenesis process. Thus, it was possible to compare microbiota characteristics between resistant and susceptible oysters families at the early steps of infection. Strikingly, we found that microbiota evenness and abundances of Cyanobacteria (Subsection III, family I), Mycoplasmataceae, Rhodobacteraceae, and Rhodospirillaceae were significantly different between resistant and susceptible oyster families. We concluded that these microbiota characteristics might predict oyster mortalities.

Published
2020
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8. Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

Author

Christelle Simon-Colin, Yannick Gueguen, Evelyne Bachere, Achraf Kouzayha, Denis Saulnier, Nicolas Gayet, and Jean Guezennec

Subjects
pearl oyster, exopolysaccharide, tachyplesin, antimicrobial, Biology (General), QH301-705.5
Abstract

Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures.

Published
2015
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9. An updated assessment of Symbiodinium spp. that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B

Author

Héloïse Rouzé, Gaël J. Lecellier, Denis Saulnier, Serge Planes, Yannick Gueguen, Herman H. Wirshing, and Véronique Berteaux-Lecellier

Subjects
Corals, French polynesia, Clade B, Symbiodinium, qPCR, Flexibility, Medicine, Biology (General), QH301-705.5
Abstract

The adaptative bleaching hypothesis (ABH) states that, depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to “switch” or “shuffle” their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community and, thus, contribute to the coral’s overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional molecular methods, to assess the presence of low-abundance (background) Symbiodinium spp. Similar to other studies, each coral species exhibited a strong specificity to a particular clade, irrespective of the environment. In addition, however, each of the five species harboured at least one additional Symbiodinium clade, among clades A–D, at background levels. Unexpectedly, and for the first time in French Polynesia, clade B was detected as a coral symbiont. These results increase the number of known coral-Symbiodinium associations from corals found in French Polynesia, and likely indicate an underestimation of the ability of the corals in this region to associate with and/or “shuffle” different Symbiodinium clades. Altogether our data suggest that corals from French Polynesia may favor a trade-off between optimizing symbioses with a specific Symbiodinium clade(s), maintaining associations with particular background clades that may play a role in the ability of corals to respond to environmental change.

Published
2017
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10. Molecular signatures discriminating the male and the female sexual pathways in the pearl oyster Pinctada margaritifera.

Author

Vaihiti Teaniniuraitemoana, Arnaud Huvet, Peva Levy, Nabila Gaertner-Mazouni, Yannick Gueguen, and Gilles Le Moullac

Subjects
Medicine, Science
Abstract

The genomics of economically important marine bivalves is studied to provide better understanding of the molecular mechanisms underlying their different reproductive strategies. The recently available gonad transcriptome of the black-lip pearl oyster Pinctada margaritifera is a novel and powerful resource to study these mechanisms in marine mollusks displaying hermaphroditic features. In this study, RNAseq quantification data of the P. margaritifera gonad transcriptome were analyzed to identify candidate genes in histologically-characterized gonad samples to provide molecular signatures of the female and male sexual pathway in this pearl oyster. Based on the RNAseq data set, stringent expression analysis identified 1,937 contigs that were differentially expressed between the gonad histological categories. From the hierarchical clustering analysis, a new reproduction model is proposed, based on a dual histo-molecular analytical approach. Nine candidate genes were identified as markers of the sexual pathway: 7 for the female pathway and 2 for the male one. Their mRNA levels were assayed by real-time PCR on a new set of gonadic samples. A clustering method revealed four principal expression patterns based on the relative gene expression ratio. A multivariate regression tree realized on these new samples and validated on the previously analyzed RNAseq samples showed that the sexual pathway of P. margaritifera can be predicted by a 3-gene-pair expression ratio model of 4 different genes: pmarg-43476, pmarg-foxl2, pmarg-54338 and pmarg-fem1-like. This 3-gene-pair expression ratio model strongly suggests only the implication of pmarg-foxl2 and pmarg-fem1-like in the sex inversion of P. margaritifera. This work provides the first histo-molecular model of P. margaritifera reproduction and a gene expression signature of its sexual pathway discriminating the male and female pathways. These represent useful tools for understanding and studying sex inversion, sex differentiation and sex determinism in this species and other related species for aquaculture purposes such as genetic selection programs.

Published
2015
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11. Yes, it turns: experimental evidence of pearl rotation during its formation

Author

Yannick Gueguen, Yann Czorlich, Max Mastail, Bruno Le Tohic, Didier Defay, Pierre Lyonnard, Damien Marigliano, Jean-Pierre Gauthier, Hubert Bari, Cedrik Lo, Sébastien Chabrier, and Gilles Le Moullac

Subjects
pearl oyster, pearl rotation, biomineralization, Science
Abstract

Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a minimum of 40 days post-grafting and continues until the pearl harvest. We measured a mean angular speed of 1.27° min−1 calculated for four different oysters. Rotation variability was observed among oysters and may be correlated to pearl shape and defects. Nature's ability to generate so amazingly complex structures like a pearl has delivered one of its secrets.

Published
2015
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12. Temperature and food influence shell growth and mantle gene expression of shell matrix proteins in the pearl oyster Pinctada margaritifera.

Author

Caroline Joubert, Clémentine Linard, Gilles Le Moullac, Claude Soyez, Denis Saulnier, Vaihiti Teaniniuraitemoana, Chin Long Ky, and Yannick Gueguen

Subjects
Medicine, Science
Abstract

In this study, we analyzed the combined effect of microalgal concentration and temperature on the shell growth of the bivalve Pinctada margaritifera and the molecular mechanisms underlying this biomineralization process. Shell growth was measured after two months of rearing in experimental conditions, using calcein staining of the calcified structures. Molecular mechanisms were studied though the expression of 11 genes encoding proteins implicated in the biomineralization process, which was assessed in the mantle. We showed that shell growth is influenced by both microalgal concentration and temperature, and that these environmental factors also regulate the expression of most of the genes studied. Gene expression measurement of shell matrix protein thereby appears to be an appropriate indicator for the evaluation of the biomineralization activity in the pearl oyster P. margaritifera under varying environmental conditions. This study provides valuable information on the molecular mechanisms of mollusk shell growth and its environmental control.

Published
2014
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13. Functional divergence in shrimp anti-lipopolysaccharide factors (ALFs): from recognition of cell wall components to antimicrobial activity.

Author

Rafael Diego Rosa, Agnès Vergnes, Julien de Lorgeril, Priscila Goncalves, Luciane Maria Perazzolo, Laure Sauné, Bernard Romestand, Julie Fievet, Yannick Gueguen, Evelyne Bachère, and Delphine Destoumieux-Garzón

Subjects
Medicine, Science
Abstract

Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded β-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a heterologous expression system. Group D ALFs were found to have impaired LPS-binding activities and only limited antimicrobial activity compared to Group B ALFs. Interestingly, all four ALF groups were shown to be simultaneously expressed in an individual shrimp and to follow different patterns of gene expression in response to a microbial infection. Group B was by far the more expressed of the ALF genes. From our results, nucleotide sequence variations in shrimp ALFs result in functional divergence, with significant differences in LPS-binding and antimicrobial activities. To our knowledge, this is the first functional characterization of the sequence diversity found in the ALF family.

Published
2013
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14. Cooperation and cheating orchestrate Vibrio assemblages and polymicrobial synergy in oysters infected with OsHV-1 virus.

Author

Oyanedel, Daniel, Lagorce, Arnaud, Bruto, Maxime, Haffner, Philippe, Morot, Amandine, Labreuche, Yannick, Dorant, Yann, Divonne, Sébastien de La Forest, Delavat, François, Inguimbert, Nicolas, Montagnani, Caroline, Morga, Benjamin, Toulza, Eve, Chaparro, Cristian, Escoubas, Jean-Michel, Yannick Gueguen, Vidal-Dupiol, Jeremie, de Lorgeril, Julien, Petton, Bruno, and Degremont, Lionel

Subjects
VIBRIO, OYSTERS, PACIFIC oysters, VIBRIO harveyi
Abstract

Polymicrobial infections threaten the health of humans and animals but remain understudied in natural systems. We recently described the Pacific Oyster Mortality Syndrome (POMS), a polymicrobial disease affecting oyster production worldwide. In the French Atlantic coast, the disease involves coinfection with ostreid herpesvirus 1 (OsHV-1) and virulent Vibrio. However, it is unknown whether consistent Vibrio populations are associated with POMS in different regions, how Vibrio contribute to POMS, and how they interact with OsHV-1 during pathogenesis. By connecting field-based approaches in a Mediterranean ecosystem, laboratory infection assays and functional genomics, we uncovered a web of interdependencies that shape the structure and function of the POMS pathobiota. We show that Vibrio harveyi and Vibrio rotiferianus are predominant in OsHV-1-diseased oysters and that OsHV-1 drives the partition of the Vibrio community observed in the field. However only V. harveyi synergizes with OsHV-1 by promoting mutual growth and accelerating oyster death. V. harveyi shows high-virulence potential and dampens oyster cellular defenses through a type 3 secretion system, making oysters a more favorable niche for microbe colonization. In addition, V. harveyi produces a key siderophore called vibrioferrin. This important resource promotes the growth of V. rotiferianus, which cooccurs with V. harveyi in diseased oysters, and behaves as a cheater by benefiting from V. harveyi metabolite sharing. Our data show that cooperative behaviors contribute to synergy between bacterial and viral coinfecting partners. Additional cheating behaviors further shape the polymicrobial consortium. Controlling cooperative behaviors or countering their effects opens avenues for mitigating polymicrobial diseases. [ABSTRACT FROM AUTHOR]

Published
2023
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15. Epigenetic then genetic variations underpin rapid adaptation of oyster populations (Crassostrea gigas) to Pacific Oyster Mortality Syndrome (POMS)

Author

Janan Gawra, Alejandro Valdivieso, Fabrice Roux, Martin Laporte, Julien de Lorgeril, Yannick Gueguen, Mathilde Saccas, Jean-Michel Escoubas, Caroline Montagnani, Delphine Destoumieux-Garzón, Franck Lagarde, Marc A. Leroy, Philippe Haffner, Bruno Petton, Céline Cosseau, Benjamin Morga, Lionel Dégremont, Guillaume Mitta, Christoph Grunau, and Jeremie Vidal-Dupiol

Subjects
oyster, exome capture, rapid adaptation, POMS, genetic, epigenetic
Abstract

Disease emergence is accelerating in response to human activity-induced global changes. Understanding the mechanisms by which host populations can rapidly adapt to this threat will be crucial for developing future management practices. Pacific Oyster Mortality Syndrome (POMS) imposes a substantial and recurrent selective pressure on oyster populations (Crassostrea gigas). Rapid adaptation to this disease may arise through both genetic and epigenetic mechanisms. In this study, we used a combination of whole exome capture of bisulfite-converted DNA, next-generation sequencing, and (epi)genome-wide association mapping, to show that natural oyster populations differentially exposed to POMS displayed signatures of selection both in their genome (single nucleotide polymorphisms) and epigenome (CG-context DNA methylation). Consistent with higher resistance to POMS, the genes targeted by genetic and epigenetic variations were mainly related to host immunity. By combining correlation analyses, DNA methylation quantitative trait loci, and variance partitioning, we revealed that a third of the observed phenotypic variation was explained by interactions between the genetic sequence and epigenetic information, ∼14% by the genetic sequence, and up to 25% by the epigenome alone. Thus, as well as genetic adaptation, epigenetic mechanisms governing immune responses contribute significantly to the rapid adaptation of hosts to emerging infectious diseases.

Published
2023

16. Cooperation and cheating orchestrate Vibrio assemblages and polymicrobial synergy in oysters infected with OsHV-1 virus

Author

Daniel Oyanedel, Arnaud Lagorce, Maxime Bruto, Philippe Haffner, Amandine Morot, Yann Dorant, Sébastien de La Forest Divonne, François Delavat, Nicolas Inguimbert, Caroline Montagnani, Benjamin Morga, Eve Toulza, Cristian Chaparro, Jean-Michel Escoubas, Yannick Labreuche, Yannick Gueguen, Jeremie Vidal-Dupiol, Julien de Lorgeril, Bruno Petton, Lionel Degremont, Delphine Tourbiez, Léa-Lou Pimparé, Marc Leroy, Océane Romatif, Juliette Pouzadoux, Guillaume Mitta, Frédérique Le Roux, Guillaume M. Charrière, Marie-Agnès Travers, and Delphine Destoumieux-Garzón

Subjects
public good, Microbiota, iron uptake, polymicrobial infection, synergy, cooperation, mollusk, dysbiosis, cheating, pathogen
Abstract

Polymicrobial diseases significantly impact the health of humans and animals but remain understudied in natural systems. We recently described the Pacific Oyster Mortality Syndrome (POMS), a polymicrobial disease that impacts oyster production and is prevalent worldwide. Analysis of POMS-infected oysters on the French North Atlantic coast revealed that the disease involves co-infection with the endemic ostreid herpesvirus 1 (OsHV-1) and virulent bacterial species such asVibrio crassostreae. However, it is unknown whether consistentVibriopopulations are associated with POMS in different regions, howVibriocontribute to POMS, and how they interact with the OsHV-1 virus during pathogenesis.We resolved theVibriopopulation structure in oysters from a Mediterranean ecosystem and investigated their functions in POMS development. We find thatVibrio harveyiandVibrio rotiferianusare the predominant species found in OsHV-1-diseased oysters and show that OsHV-1 is necessary to reproduce the partition of theVibriocommunity observed in the field. By characterizing the interspecific interactions between OsHV-1,V. harveyiandV. rotiferianus, we find that onlyV. harveyisynergizes with OsHV-1. When co-infected, OsHV-1 andV. harveyibehave cooperatively by promoting mutual growth and accelerating oyster death.V. harveyishowed high virulence potential in oysters and dampened host cellular defenses, making oysters a more favorable niche for microbe colonization. We next investigated the interactions underlying the co-occurrence of diverseVibriospecies in diseased oysters. We found thatV. harveyiharbors genes responsible for the biosynthesis and uptake of a key siderophore called vibrioferrin. This important resource promotes the growth ofV. rotiferianus, a cheater that efficiently colonizes oysters during POMS without costly investment in host manipulation nor metabolite sharing.By connecting field-based approaches, laboratory infection assays and functional genomics, we have uncovered a web of interdependencies that shape the structure and function of the POMS pathobiota. We showed that cooperative behaviors contribute to synergy between bacterial and viral co-infecting partners. Additional cheating behaviors further shape the polymicrobial consortium. Controlling such behaviors or countering their effects opens new avenues for mitigating polymicrobial diseases.

Published
2023

17. Seaweeds influence oyster microbiota and disease susceptibility

Author

Petton Bruno, Yannick Gueguen, Elyne Dugény, Fabrice Pernet, Eve Toulza, De Lorgeril Julien, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), and European Project: 678589,H2020,H2020-SFS-2015-2,VIVALDI(2016)

Subjects
macroalgae, Microbiota, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, food and beverages, microbiome, Seaweed, bivalve, disease ecology, Animals, Animal Science and Zoology, Seawater, epidemiology, Disease Susceptibility, Crassostrea, Ecology, Evolution, Behavior and Systematics, pathogen
Abstract

International audience; 1-A growing awareness of role that microbiota can play in mediating the effects of pathogens on hosts has given rise to the concept of the pathobiome. Recently, we demonstrated that the Pacific oyster mortality syndrome affecting Crassostrea gigas oysters is caused by infection with the Ostreid herpesvirus type 1 (OsHV-1) followed by infection with multiple bacterial taxa. 2-Here we extend the concept of this pathobiome beyond the host species and its bacterial microbiota by investigating how seaweed living in association with oysters influences their response to the disease. We hypothesized that by their mere presence in the environment, different species of seaweeds can positively or negatively influence the risk of disease in oysters by shaping their bacterial microbiota and their immune response. Although seaweed and oysters do not have direct ecological interactions, they are connected by seawater and likely share microbes. 3-To test our hypothesis, oysters were acclimated with green, brown or red algae for 2 weeks and then challenged with OsHV-1. We monitored host survival and pathogen proliferation and performed bacterial microbiota and transcriptome analyses. 4-We found that seaweeds can alter the bacterial microbiota of the host and its response to the disease. More particularly, green algae belonging to the genus Ulva spp. induced bacterial microbiota dysbiosis in oyster and modification of its transcriptional immune response leading to increased susceptibility to the disease. 5-This work provides a better understanding of a marine disease and highlights the importance of considering both macrobiotic and microbiotic interactions for conservation, management and exploitation of marine ecosystems and resources.

Published
2022

18. Recent advances in bivalve-microbiota interactions for disease prevention in aquaculture

Author

Isabelle Arzul, Luigi Vezzulli, K. Mathias Wegner, Alberto Pallavicini, Christine Paillard, Yannick Gueguen, David Bass, Paillard, Christine, Gueguen, Yannick, Wegner, K Mathia, Bass, David, Pallavicini, Alberto, Vezzulli, Luigi, Arzul, Isabelle, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Alfred Wegener Institute for Polar and Marine Research (AWI), The Natural History Museum [London] (NHM), Centre for Environment, Fisheries and Aquaculture Science [Weymouth] (CEFAS), Department of Life Sciences, Università degli studi di Trieste, National Institute of Oceanography and Applied Geophysics (OGS), Dipartimento di Scienze della Terra dell'Ambiente e della Vita (DISTAV), Universita degli studi di Genova, Laboratoire de Génétique et Pathologie des Mollusques Marins, 17390 La Tremblade, France. (LGPMM), Santé, Génétique et Microbiologie des Mollusques (IFREMER SG2M), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Università degli studi di Trieste = University of Trieste, Università degli studi di Genova = University of Genoa (UniGe), Laboratoire de Génétique et Pathologie des Mollusques Marins (LGPMM), Santé, Génétique et Microbiologie des Mollusques (SGMM), and ANR-17-EURE-0015,ISBlue,Interdisciplinary Graduate School for the Blue planet(2017)

Subjects
Functional role, Biomedical Engineering, Bioengineering, Context (language use), [SDV.SA.ZOO]Life Sciences [q-bio]/Agricultural sciences/Zootechny, Disease, Aquaculture, Biology, Animals, Host-Pathogen Interactions, Bivalvia, Microbiota, 03 medical and health sciences, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Ecology, Host (biology), business.industry, Animal, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Host-Pathogen Interaction, 13. Climate action, [SDE]Environmental Sciences, Disease prevention, business, Biotechnology, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract

International audience; In bivalves, no clear-cut functional role of microbiota has yet been identified, although many publications suggest that they could be involved in nutrition or immunity of their host. In the context of climate change, integrative approaches at the crossroads of disciplines have been developed to explore the environment-host-pathogen microbiota system. Here, we attempt to synthesize work on (1) the current methodologies to analyse bivalve microbiota, (2) the comparison of microbiota between species, between host compartments and their surrounding habitat, (3) how the bivalve microbiota are governed by environmental factors and host genetics and (4) how host-associated microorganisms act as a buffer against pathogens and/or promote recovery, and could thereby play a role in the prevention of disease or mortalities.

Published
2022

19. Oyster hemolymph is a complex and dynamic ecosystem hosting bacteria, protists and viruses

Author

Yannick Gueguen, J. de Lorgeril, Samuel Dupont, C. Salmeron, G. Tanguy, Caroline Montagnani, J.Y. Bou Khalil, Jean-Christophe Auguet, Jean-Michel Escoubas, Bruno Petton, B. La Scola, Eve Toulza, A. Lokmer, Christelle Desnues, Guillaume Mitta, David Pecqueur, Erwan Corre, Laure Guillou, Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Éco-Anthropologie (EA), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), ABiMS - Informatique et bioinformatique = Analysis and Bioinformatics for Marine Science (ABIMS), Fédération de recherche de Roscoff (FR2424), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Observatoire océanologique de Banyuls (OOB), Adaptation et diversité en milieu marin (ADMM), Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), ECOlogy of MArine Plankton (ECOMAP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Microbes évolution phylogénie et infections (MEPHI), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut Hospitalier Universitaire Méditerranée Infection (IHU Marseille), The present study was supported by: the DHOF program of the UMR5244/IHPE (http://ihpe.univ-perp.fr/en/ihpe-transversal-holobiont/), the Ifremer project HémoMicrobiote, EMBRC-France, whose French state funds are managed by the ANR within the Investments of the Future (ANR-10-INBS-02), the ANR projects DECIPHER (ANR-14-CE19–0023) and ENVICOPAS (ANR-15-CE35–0004), the EU funded project VIVALDI (H2020 program, n°678589), by Ifremer, CNRS, Université de Montpellier, Université de Perpignan via Domitia, by the IHU Méditerranée Infection, Marseille, France, by the French Government under the «Investissements d’avenir» program (reference: Méditerranée Infection 10-IAHU-03) and by the Région Provence-Alpes-Côte d’Azur and by the European funding FEDER PRIMI. This study is set within the framework of the 'Laboratoires d’Excellences (LABEX)' TULIP (ANR-10-LABX-41)., ANR-10-INBS-0002,EMBRC-France,CENTRE NATIONAL DE RESSOURCES BIOLOGIQUES MARINES(2010), ANR-14-CE19-0023,DECIPHER,Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître(2014), ANR-15-CE35-0004,ENVICOPAS,Impact des changements environnementaux sur les organismes pathogènes dans les écosystèmes côtiers(2015), ANR-11-IDEX-0002,UNITI,Université Fédérale de Toulouse(2011), European Project: 678589,H2020,H2020-SFS-2015-2,VIVALDI(2016), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Éco-Anthropologie (EAE), ABiMS - Informatique et bioinformatique = Analysis and Bioinformatics for Marine Science (FR2424), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO), Adaptation et diversité en milieu marin (AD2M), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Institut d’Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520 (IEMN), Ecole Centrale de Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire Bordelais de Recherche en Informatique (LaBRI), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Université Sciences et Technologies - Bordeaux 1-Université Bordeaux Segalen - Bordeaux 2, Institut Hospitalier Universitaire Méditerranée Infection (IHU AMU), Génome, populations, interactions, adaptation (GPIA), Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université Montpellier 2 - Sciences et Techniques (UM2), Parasitologie fonctionnelle et évolutive (PFE), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Radiopathologie et Thérapies Expérimentales [IRSN, Fontenay-aux-Roses] (PRP-HOM - SRBE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Oyster, animal structures, Early-life microbiota, lcsh:QR1-502, Zoology, medicine.disease_cause, Within-host ecosystem, lcsh:Microbiology, 03 medical and health sciences, biology.animal, medicine, Trans-kingdom interactions, Human virome, Microbiome, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Ecological niche, 0303 health sciences, lcsh:Veterinary medicine, biology, 030306 microbiology, Host (biology), Oyster genetic background, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, Protist, General Medicine, Pacific oyster, biology.organism_classification, Transplantation, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, [SDE]Environmental Sciences, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, Crassostrea gigas, lcsh:SF600-1100, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Acln, Hemolymph microbiota dynamics, Research Article
Abstract

Background The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health. Results We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a natural environment either before or during a disease outbreak. Using metabarcoding and shotgun metagenomics, we demonstrate that hemolymph can be considered as an ecological niche hosting bacterial, protist and viral communities, each of them shaped by different factors and distinct from the corresponding communities in the surrounding seawater. Overall, we found that hemolymph microbiota is more strongly shaped by the environment than by host genetic background. Co-occurrence network analyses suggest a disruption of the microbial network after transplantation into natural environment during both non-infectious and infectious periods. Whereas we could not identify a common microbial community signature for healthy animals, OsHV-1 μVar virus dominated the hemolymph virome during the disease outbreak, without significant modifications of other microbiota components. Conclusion Our study shows that oyster hemolymph is a complex ecosystem containing diverse bacteria, protists and viruses, whose composition and dynamics are primarily determined by the environment. However, all of these are also shaped by oyster genetic backgrounds, indicating they indeed interact with the oyster host and are therefore not only of transient character. Although it seems that the three microbiome components respond independently to environmental conditions, better characterization of hemolymph-associated viruses could change this picture.

Published
2020

20. Differential basal expression of immune genes confers Crassostrea gigas resistance to Pacific oyster mortality syndrome

Author

Jean-Michel Escoubas, Philippe Haffner, Bruno Petton, Franck Lagarde, Yannick Gueguen, Aude Lucasson, Valérie Perez, Pierre-Louis Stenger, Jean-François Allienne, Caroline Montagnani, Julien de Lorgeril, M. Leroy, Guillaume Mitta, Jeremie Vidal-Dupiol, Lionel Degremont, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Génétique et Pathologie des Mollusques Marins, 17390 La Tremblade, France. (LGPMM), Santé, Génétique et Microbiologie des Mollusques (IFREMER SG2M), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), The present study was supported by the ANR project DECIPHER (ANR-14-CE19–0023), by the ANR project DECICOMP and by Ifremer, CNRS, Université de Montpellier and Université de Perpignan via Domitia., ANR-14-CE19-0023,DECIPHER,Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître(2014), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Laboratoire de Génétique et Pathologie des Mollusques Marins (LGPMM), Santé, Génétique et Microbiologie des Mollusques (SGMM), and Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Oyster, animal structures, Invertebrate immunity, lcsh:QH426-470, lcsh:Biotechnology, Resistance, Transcriptome, 03 medical and health sciences, Antiviral molecular pathways, Stress, Physiological, biology.animal, lcsh:TP248.13-248.65, Genotype, Genetics, Animals, Pacific oyster, RNA-Seq, 14. Life underwater, Crassostrea, Gene, Panzootic, 030304 developmental biology, 0303 health sciences, biology, OsHV-1, Acl, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Oyster disease, food and beverages, 04 agricultural and veterinary sciences, biology.organism_classification, Phenotype, lcsh:Genetics, Genes, 040102 fisheries, 0401 agriculture, forestry, and fisheries, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Biotechnology, Research Article
Abstract

Background As a major threat to the oyster industry, Pacific Oyster Mortality Syndrome (POMS) is a polymicrobial disease affecting the main oyster species farmed across the world. POMS affects oyster juveniles and became panzootic this last decade, but POMS resistance in some oyster genotypes has emerged. While we know some genetic loci associated with resistance, the underlying mechanisms remained uncharacterized. So, we developed a comparative transcriptomic approach using basal gene expression profiles between different oyster biparental families with contrasted phenotypes when confronted to POMS (resistant or susceptible). Results We showed that POMS resistant oysters show differential expression of genes involved in stress responses, protein modifications, maintenance of DNA integrity and repair, and immune and antiviral pathways. We found similarities and clear differences among different molecular pathways in the different resistant families. These results suggest that the resistance process is polygenic and partially varies according to the oyster genotype. Conclusions We found differences in basal expression levels of genes related to TLR-NFκB, JAK-STAT and STING-RLR pathways. These differences could explain the best antiviral response, as well as the robustness of resistant oysters when confronted to POMS. As some of these genes represent valuable candidates for selective breeding, we propose future studies should further examine their function.

Published
2020

21. In situ characterisation of pathogen dynamics during a Pacific Oyster Mortality Syndrome episode

Author

Yannick Gueguen, Gregory Messiaen, Behzad Mostajir, Martine Fortune, Marion Richard, Serge Mortreux, Franck Lagarde, Patrik Le Gall, Emmanuelle Roque D'Orbcastel, David Parin, Julien de Lorgeril, Juliette Pouzadoux, Sébastien Mas, Béatrice Bec, Annie Fiandrino, Jean Luc Rolland, Laboratoire Service d' Experimentations Aquacoles [Palavas les Flots] (LSEA MARBEC), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Observatoire de REcherche Méditerranéen de l'Environnement (OSU OREME), Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
0106 biological sciences, Oyster, animal structures, Ostreid herpesvirus 1, Zoology, [SDV.SA.ZOO]Life Sciences [q-bio]/Agricultural sciences/Zootechny, Aquaculture, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, biology.animal, Animals, Disease, 14. Life underwater, Crassostrea, Shellfish, Vibrio, [SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health, Bacteria, biology, Thau lagoon, Microbiota Bacteria, business.industry, Microbiota, 010604 marine biology & hydrobiology, fungi, food and beverages, Pelagic zone, General Medicine, Pacific oyster, biology.organism_classification, Pollution, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Arcobacter, Crassostrea gigas, France, business
Abstract

International audience; Significant mortality of Crassostrea gigas juveniles is observed systematically every year worldwide. Pacific Oyster Mortality Syndrome (POMS) is caused by Ostreid Herpesvirus 1 (OsHV-1) infection leading to immune suppression, followed by bacteraemia caused by a consortium of opportunistic bacteria. Using an in-situ approach and pelagic chambers, our aim in this study was to identify pathogen dynamics in oyster flesh and in the water column during the course of a mortality episode in the Mediterranean Thau lagoon (France). OsHV-1 concentrations in oyster flesh increased before the first clinical symptoms of the disease appeared, reached maximum concentrations during the moribund phase and the mortality peak. The structure of the bacterial community associated with oyster flesh changed in favour of bacterial genera previously associated with oyster mortality including Vibrio, Arcobacter, Psychrobium, and Psychrilyobacter. During the oyster mortality episode, releases of OsHV-1 and opportunistic bacteria were observed, in succession, in the water surrounding the oyster lanterns. These releases may favour the spread of disease within oyster farms and potentially impact other marine species, thereby reducing marine biodiversity in shellfish farming areas

Published
2021

22. A core of functional complementary bacteria infects oysters in Pacific Oyster Mortality Syndrome

Author

Lionel Degremont, Guillaume Mitta, Yannick Gueguen, Eve Toulza, Delphine Destoumieux-Garzón, Camille Clerissi, Aude Lucasson, Julien de Lorgeril, Shogofa Mortaza, Jean-Michel Escoubas, Xing Luo, Annick Jacq, Bruno Petton, Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génétique et Pathologie des Mollusques Marins (LGPMM), Santé, Génétique et Microbiologie des Mollusques (SGMM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), ANR-14-CE19-0023,DECIPHER,Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître(2014), ANR-19-CE20-0004,DECICOMP,Déchiffrer toute la complexité du syndrome de mortalité des huîtres du Pacifique pour modéliser le risque épidémiologique.(2019), ANR-10-LABX-0041,TULIP,Towards a Unified theory of biotic Interactions: the roLe of environmental(2010), Université de Perpignan Via Domitia (UPVD), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), ANR-15-NEUR-0001,DeCipher,Deciphering hyperexcitable networks associated with neurodevelopmental lesions(2015), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Laboratoire de Génétique et Pathologie des Mollusques Marins, 17390 La Tremblade, France. (LGPMM), Santé, Génétique et Microbiologie des Mollusques (IFREMER SG2M), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique)

Subjects
Oyster, animal structures, Virulence, 03 medical and health sciences, biology.animal, Pathobiota, 14. Life underwater, Resource partitioning, Metatranscriptomics, 030304 developmental biology, Genetics, 0303 health sciences, biology, 030306 microbiology, Host (biology), [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, Natural competence, General Medicine, Metabarcoding Metatranscriptomics Pathobiota Metabolism Resource partitioning, Pacific oyster, biology.organism_classification, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Quorum sensing, Metabolism, Metabarcoding, bacteria, Crassostrea, Bacteria
Abstract

The Pacific oyster Crassostrea gigas is one of the main cultivated invertebrate species around the world. Since 2008, oyster juveniles have been confronted with a lethal syndrome, Pacific Oyster Mortality Syndrome (POMS). The etiology of POMS is complex. Recently, we demonstrated that POMS is a polymicrobial disease. It is initiated by a primary infection with the herpesvirus OsHV-1 µ Var, and evolves towards a secondary fatal bacteremia that is enabled by the oyster's immunocompromised state. In the present article, we describe the implementation of an unprecedented combination of metabarcoding and metatranscriptomic approaches to show that the sequence of events in POMS pathogenesis is conserved across infectious environments and susceptible oyster genetic backgrounds. We also identify a core colonizing bacterial consortium which, together with OsHV-1 µ Var, forms the POMS pathobiota. This bacterial core is characterized by highly active global metabolism and key adaptive responses to the within-host environment (e.g. stress responses and redox homeostasis). Several marine gamma proteobacteria in the core express different and complementary functions to exploit the host's resources. Such cross-benefits are observed in colonization-related functions, and reveal specific strategies used by these bacteria to adapt and colonize oysters (e.g. adhesion, cell defense, cell motility, metal homeostasis, natural competence, quorum sensing, transport, and virulence). Interdependence and cooperation within the microbial community for metabolic requirements is best exemplified by sulfur metabolism, which is a property of the pathobiota as a whole and not of a single genus. We argue that this interdependence may dictate the conservation of the POMS pathobiota across distinct environments and oyster genetic backgrounds.

Published
2020

23. A Sustained Immune Response Supports Long-Term Antiviral Immune Priming in the Pacific Oyster, Crassostrea gigas

Author

Julien de Lorgeril, Guillaume Mitta, Cristian Chaparro, Agnès Vergnes, Delphine Destoumieux-Garzón, Bruno Petton, Philippe Haffner, Célia Barrachina, Yannick Gueguen, Jeremie Vidal-Dupiol, Caroline Montagnani, Maxime Lafont, Benjamin Gourbal, Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Génomique Fonctionnelle - Montpellier GenomiX (IGF MGX), Institut de Génomique Fonctionnelle (IGF), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-BioCampus (BCM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ANR-14-CE19-0023,DECIPHER,Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître(2014), ANR-13-JSV7-0009,INVIMORY,Immunité mémoire chez les invertébrés : spécificité et mécanismes de l'immunité mémoire chez le mollusque Lophotrochozoaire Biomphalaria glabrata.(2013), ANR-11-IDEX-0002,UNITI,Université Fédérale de Toulouse(2011), European Project: 678589,H2020,H2020-SFS-2015-2,VIVALDI(2016), Modat, Anne, Appel à projets générique - Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître - - DECIPHER2014 - ANR-14-CE19-0023 - Appel à projets générique - VALID, Jeunes Chercheuses et Jeunes Chercheurs - Immunité mémoire chez les invertébrés : spécificité et mécanismes de l'immunité mémoire chez le mollusque Lophotrochozoaire Biomphalaria glabrata. - - INVIMORY2013 - ANR-13-JSV7-0009 - JC - VALID, Initiative d'excellence - Université Fédérale de Toulouse - - UNITI2011 - ANR-11-IDEX-0002 - IDEX - VALID, Preventing and mitigating farmed bivalve diseases - VIVALDI - - H20202016-03-01 - 2020-02-29 - 678589 - VALID, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Oyster, invertebrate-microbe interactions, Priming (immunology), poly(I-C), immune memory, Transcriptome, antiviral response, Interferon, innate immunity, 0303 health sciences, oyster, biology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], 030302 biochemistry & molecular biology, interferon, Pacific oyster, Acquired immune system, QR1-502, DNA Virus Infections, Up-Regulation, interferons, poly(I·C), medicine.drug, animal structures, Microbiology, ostreid herpesvirus, Host-Microbe Biology, 03 medical and health sciences, Immune system, Virology, biology.animal, medicine, [SDV.BID.EVO] Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Animals, POMS, 14. Life underwater, Crassostrea, priming, 030304 developmental biology, Innate immune system, OsHV-1, Gene Expression Profiling, fungi, DNA Viruses, mollusks, transcriptomic, biology.organism_classification, Immunity, Innate, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, Poly I-C, Immunology, Commentary, bacteria, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract

Viral diseases cause significant losses in aquaculture. Prophylactic measures, such as immune priming, are promising control strategies. Treatment of the Pacific oyster (Crassostrea gigas) with the double-stranded RNA analog poly(I·C) confers long-term protection against infection with ostreid herpesvirus 1, the causative agent of Pacific oyster mortality syndrome. In a recent article in mBio, Lafont and coauthors (M. Lafont, A. Vergnes, J. Vidal-Dupiol, J., Viral diseases cause significant losses in aquaculture. Prophylactic measures, such as immune priming, are promising control strategies. Treatment of the Pacific oyster (Crassostrea gigas) with the double-stranded RNA analog poly(I·C) confers long-term protection against infection with ostreid herpesvirus 1, the causative agent of Pacific oyster mortality syndrome. In a recent article in mBio, Lafont and coauthors (M. Lafont, A. Vergnes, J. Vidal-Dupiol, J. de Lorgeril, et al., mBio 11:e02777-19, 2020, https://doi.org/10.1128/mBio.02777-19) characterized the transcriptome of oysters treated with poly(I·C). This immune stimulator induced genes related to the interferon and apoptosis pathways. This response overlaps the response to viral infection, and high expression levels of potential effector genes are maintained for up to 4 months. This work opens the door to characterization of the phenomena of immune priming in a poorly studied invertebrate model. It also highlights the importance of interferon-like responses for invertebrate antiviral immunity.

Published
2020

24. Non‐invasive functional exploration techniques for bivalves with applications to pearl oyster Pinctada margaritifera

Author

Yannick Gueguen, Sébastien Chabrier, Pierre Lyonnard, Gilles Le Moullac, Léo Milhade, Claude Soyez, Benoit Beliaeff, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Géopôle du Pacifique Sud (GePaSUD), Université de la Polynésie Française (UPF), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
[SDV.SA.ZOO]Life Sciences [q-bio]/Agricultural sciences/Zootechny, Management, Monitoring, Policy and Law, Aquatic Science, engineering.material, bivalve, 03 medical and health sciences, 14. Life underwater, Organism, 030304 developmental biology, filtration, Current range, 0303 health sciences, Ecology, biology, Individual animal, Pearl oyster, Non invasive, Pinctada margaritifera, valvometry, 04 agricultural and veterinary sciences, biology.organism_classification, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Fishery, pearl rotation, 040102 fisheries, engineering, 0401 agriculture, forestry, and fisheries, Pearl, respiration
Abstract

International audience; Non-invasive functional exploration techniques can provide information on different aspects of general organism functioning and, unlike lethal or invasive techniques, allow individual organisms to be monitored for as long as necessary. For bivalves, a fairly wide variety of methods and instrumental means exist allowing physiology to be assessed on-line while keeping animals alive and intact. The current range of non-invasive techniques for bivalves consists of systems for measuring metabolic flows and valve activity, which can be used on bivalve molluscs for as long as an individual animal's characteristics (e.g. size) make this technically feasible. In this paper, we present some of these noninvasive techniques with applications for pearl oyster and list other potentially promising techniques. We also focus on a unique method we developed specifically for to record the pearl rotation characteristics within pearl oysters. This article presents the state of the art in non-invasive functional exploration techniques. We hope that the information provided here will be useful to physiologists of bivalve marine molluscs through the tools and applications presented here or other future approaches based on them.

Published
2020

25. Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers

Author

Saulnier Denis, Santini Adrien, Le Moullac Gilles, Bouisset Patrick, Garen Pierre, Bernagout Solène, Magre Kevin, Helme Herehia, Yannick Gueguen, Planes Serge, Nohl Marine, Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Laboratoire d'étude et de suivi de l'environnement (IRSN/PSE-ENV/SEREN/LESE), Service d'expertise et d'étude en radioprotection des populations et de la radioactivité dans l'environnement (IRSN/PSE-ENV/SEREN), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), PSE-ENV/SEREN/LESE, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), and Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École pratique des hautes études (EPHE)

Subjects
Chromium, 0301 basic medicine, Antioxidant, medicine.medical_treatment, Sentinel species, French Polynesia, chemistry.chemical_element, 010501 environmental sciences, Aquatic Science, engineering.material, Oceanography, 01 natural sciences, Pinctada margaritifera, 03 medical and health sciences, medicine, Animals, Metallothionein, Pinctada, 14. Life underwater, Ecosystem, Margaritifera, 0105 earth and related environmental sciences, Cadmium, biology, Ecology, Contamination, biology.organism_classification, Pollution, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, 030104 developmental biology, chemistry, Environmental chemistry, engineering, Gene expression, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, Pearl, Biomarkers
Abstract

International audience; This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.

Published
2017

26. Impact of pCO2 on the energy, reproduction and growth of the shell of the pearl oyster Pinctada margaritifera

Author

Alain Lo-Yat, Jeremie Vidal-Dupiol, Denis Saulnier, Manaarii Sham-Koua, Claude Soyez, Yannick Gueguen, G. Le Moullac, Corinne Belliard, Julie Fievet, Nabila Gaertner-Mazouni, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
Biomineralization, 0106 biological sciences, 0301 basic medicine, Oyster, Bioenergetics, Bioenergetic, French Polynesia, Zoology, Aquatic Science, Oceanography, 01 natural sciences, pCO2, 03 medical and health sciences, Aquaculture, biology.animal, Pearl oyster, 14. Life underwater, Global change, Shellfish, Gametogenesis, Pacific Ocean, biology, Ecology, business.industry, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], 010604 marine biology & hydrobiology, Pinctada margaritifera, Aquatic animal, biology.organism_classification, 030104 developmental biology, business
Abstract

International audience; The possible consequences of acidification on pearl farming are disruption of oyster metabolism and change in growth. In the laboratory, we studied the impact of pCO2 (3540, 1338 and 541μatm) on the physiology of pearl oysters exposed for 100 days. This experiment was repeated after an interval of one year. Several physiological compartments were examined in pearl oysters: the scope for growth by measuring ingestion, assimilation and oxygen consumption, gametogenesis by means of histological observations, shell growth by measurement and observation by optical and electronic microscopy, and at molecular level by measuring the expression of nine genes of mantle cells implied in the biomineralisation process. Results from both experiments showed that high pCO2 had no effect on scope for growth and gametogenesis. High pCO2 (3540 μatm) significantly slowed down the shell deposit rate at the ventral side and SEM observations of the inside of the shell found signs of chemical dissolution. Of the nine examined genes high pCO2significantly decreased the expression level of one gene (Pmarg-PUSP 6). This study showed that shell growth of the pearl oyster would be slowed down without threatening the species since the management of energy and reproduction functions appeared to be preserved. Further investigations should be conducted on the response of offspring to acidification.

Published
2016

27. Effect of temperature, food availability, and estradiol injection on gametogenesis and gender in the pearl oysterPinctada margaritifera

Author

Vaihiti Teaniniuraitemoana, Maxime Lepretre, Gilles Le Moullac, Vincent Vanaa, Yannick Gueguen, Nabila Gaertner-Mazouni, Peva Levy, Sophie Parrad, and Arnaud Huvet

Subjects
0301 basic medicine, Physiology, media_common.quotation_subject, Zoology, 03 medical and health sciences, Hermaphrodite, Botany, Genetics, 14. Life underwater, Molecular Biology, Ecology, Evolution, Behavior and Systematics, Margaritifera, Gametogenesis, media_common, biology, Pinctada margaritifera, 04 agricultural and veterinary sciences, Pacific oyster, biology.organism_classification, 030104 developmental biology, 040102 fisheries, 0401 agriculture, forestry, and fisheries, Animal Science and Zoology, Reproduction, Sex ratio, Pinctada
Abstract

The black-lip pearl oyster Pinctada margaritifera is a protandrous hermaphrodite species. Its economic value has led to the development of controlled hatchery reproduction techniques, although many aspects remain to be optimized. In order to understand reproductive mechanisms and their controlling factors, two independent experiments were designed to test hypotheses of gametogenesis and sex ratio control by environmental and hormonal factors. In one, pearl oysters were exposed under controlled conditions at different combinations of temperature (24 and 28°C) and food level (10,000 and 40,000 cells mL−1); whereas in the other, pearl oysters were conditioned under natural conditions into the lagoon and subjected to successive 17β-estradiol injections (100 μg per injection). Gametogenesis and sex ratio were assessed by histology for each treatment. In parallel, mRNA expressions of nine marker genes of the sexual pathway (pmarg-foxl2, pmarg-c43476, pmarg-c45042, pmarg-c19309, pmarg-c54338, pmarg-vit6, pmarg-zglp1, pmarg-dmrt, and pmarg-fem1-like) were investigated. Maximum maturation was observed in the treatment combining the highest temperature (28°C) and the highest microalgae concentration (40,000 cells mL−1), where the female sex tended to be maintained. Injection of 17β-estradiol induced a significant increase of undetermined stage proportion 2 weeks after the final injection. These results suggest that gametogenesis and gender in adult pearl oysters can be controlled by environmental factors and estrogens. While there were no significant effects on relative gene expression, the 3-gene-pair expression ratio model of the sexual pathway of P. margaritifera, suggest a probable dominance of genetic sex determinism without excluding a mixed sex determination mode (genetic + environmental).

Published
2015

28. Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field

Author

Patrik Le Gall, Yannick Gueguen, Patrice Got, Fabrice Pernet, Agnès Vergnes, Vincent Loubiere, Evelyne Bachère, Jean-Luc Jeannot, Fabien Aujoulat, Estelle Jumas-Bilak, Delphine Destoumieux-Garzón, Julien de Lorgeril, Jean-Michel Escoubas, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Hydrosciences Montpellier (HSM), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes lagunaires : organisation biologique et fonctionnement (ECOLAG), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Oyster, animal structures, Mollusk, Host–pathogen interaction, 030106 microbiology, Disease, Aquatic Science, Microbiology, 03 medical and health sciences, Immune system, Immunity, biology.animal, Animals, Environmental Chemistry, Juvenile, Seawater, 14. Life underwater, Invertebrate, Crassostrea, In situ mortality, Herpesviridae, Vibrio, Innate immunity, Innate immune system, biology, ACL, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, Temperature, food and beverages, General Medicine, biology.organism_classification, equipment and supplies, Immunity, Innate, 030104 developmental biology, Total bacteria, Host pathogen interaction, Crassostrea gigas, bacteria, France, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract

International audience; Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European fanning areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus Glade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We found that, in contrast to resistant adult oysters having survived an earlier episode of mortality, susceptible juvenile oysters never exposed to infectious episodes died by more than 90% in a field experiment. Susceptible oysters were heavily colonized by OsHV-1 herpes virus as well as bacteria including vibrios potentially pathogenic for oysters, which proliferated in oyster flesh and body fluids during the mortality event. Nonetheless, susceptible oysters were found to sense microbes as indicated by an overexpression of immune receptors and immune signaling pathways. However, they did not express important immune effectors involved in antimicrobial immunity and apoptosis and showed repressed expression of genes involved in ROS and metal homeostasis. This contrasted with resistant oysters, which expressed those important effectors, controlled bacterial and viral colonization and showed 100% survival to the mortality event. Altogether, our results demonstrate that the immune response mounted by susceptible oysters lacks some important immune functions and fails in controlling microbial proliferation. This study opens the way to more holistic studies on the "mass mortality syndrome", which are now required to decipher the sequence of events leading to oyster mortalities and determine the relative weight of pathogens, oyster genetics and oyster-associated microbiota in the disease.

Published
2018

29. Biofouling development and its effect on growth and reproduction of the farmed pearl oyster Pinctada margaritifera

Author

Nabila Gaertner-Mazouni, Élise Lacoste, Yannick Gueguen, Gilles Le Moullac, Peva Levy, Institut français de recherche pour l'exploitation de la mer, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Interactions Hôtes-Pathogènes-Environnements (IHPE), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD)

Subjects
0106 biological sciences, STRESS, Biofouling, Pteriidae, CRASSOSTREA-GIGAS THUNBERG, SUCCESSION, media_common.quotation_subject, NEW-ZEALAND, Pearl oyster culture, Growth, Aquatic Science, engineering.material, 01 natural sciences, Pinctada margaritifera, Aquaculture, PTERIIDAE, SUSPENDED CULTURE, Colonization, 14. Life underwater, MAXIMA, media_common, biology, business.industry, Reproduction, 010604 marine biology & hydrobiology, Pearl oyster, food and beverages, 04 agricultural and veterinary sciences, biology.organism_classification, eye diseases, FRENCH-POLYNESIA, 3. Good health, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Fishery, FUCATA, 040102 fisheries, engineering, FOULING ORGANISMS, 0401 agriculture, forestry, and fisheries, business, Pearl
Abstract

International audience; In bivalve aquaculture, dominant fouling organisms are filter feeders which can compete for food with reared bivalves, sometimes causing mortality or reducing their growth rate. This study investigated the effect of biofouling on the farmed pearl oyster Pinctada margantifera in two lagoons of French Polynesia. Survival, growth and reproduction of 2 year-old pearl oysters were monitored with regular sampling schedules, from the initial stage of colonization up to 20 months of biofouling accumulation. Control groups of pearl oysters were kept free of biofouling as is the current practice in pearl farms. After more than a year of monitoring, no significant difference was recorded in shell growth rate between pearl oysters reared with epibionts and the control group of pearl oysters, at both sites. Mean annual shell growth rate (height) was 30.5 +/- 9.2 mm in Tahiti and 24.8 +/- 7.7 mm in Mangareva. Neither the survival nor the reproduction indices were negatively affected by biofouling. In Mangareva, where biofouling development was quantified during 1 year, the rate of colonization appeared to be high during the first 3 months before slowing down. These results raise questions about the necessity of removing biofouling at this stage of pearl oyster production (i.e. before grafting).

Published
2014

30. An updated assessment of Symbiodinium spp. that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B

Author

Denis Saulnier, Serge Planes, Gaël Lecellier, Yannick Gueguen, Héloïse Rouzé, Véronique Berteaux-Lecellier, Herman H. Wirshing, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Université Paris-Saclay, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, Smithsonian Institution, Université des Antilles (UA)-Institut d'écologie et environnement-Université de la Nouvelle-Calédonie (UNC)-Université de la Polynésie Française (UPF)-Université de La Réunion (UR)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Université des Antilles et de la Guyane (UAG)-Institut de Recherche pour le Développement (IRD), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
0106 biological sciences, Environmental change, Coral bleaching, Coral, lcsh:Medicine, Marine Biology, Generalist, Biology, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Symbiodinium, Symbiosis, Clade B, natural sciences, 14. Life underwater, Clade, Molecular Biology, Faithful clade, Ecology, 010604 marine biology & hydrobiology, General Neuroscience, lcsh:R, fungi, technology, industry, and agriculture, Biodiversity, General Medicine, computer.file_format, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, qPCR, Corals, RDFa, French polynesia, Flexibility, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, General Agricultural and Biological Sciences, computer, geographic locations
Abstract

International audience; The adaptative bleaching hypothesis (ABH) states that, depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to ''switch'' or ''shuffle'' their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community and, thus, contribute to the coral's overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional molecular methods, to assess the presence of low-abundance (background) Symbiodinium spp. Similar to other studies, each coral species exhibited a strong specificity to a particular clade, irrespective of the environment. In addition, however, each of the five species harboured at least one additional Symbiodinium clade, among clades A–D, at background levels. Unexpectedly, and for the first time in French Polynesia, clade B was detected as a coral symbiont. These results increase the number of known coral-Symbiodinium associations from corals found in French Polynesia, and likely indicate an underestimation of the ability of the corals in this region to associate with and/or ''shuffle'' different Symbiodinium clades. Altogether our data suggest that corals from French Polynesia may favor a trade-off between optimizing symbioses with a specific Symbiodinium clade(s), maintaining associations with particular background clades that may play a role in the ability of corals to respond to environmental change. How to cite this article Rouzé et al. (2017), An updated assessment of Symbiodinium spp. that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B.

Published
2017

31. Pinctada margaritifera responses to temperature and pH: Acclimation capabilities and physiological limits

Author

Denis Saulnier, Juliette Fremery, Claude Soyez, Gilles Le Moullac, Jeremie Vidal-Dupiol, Oïhana Latchere, Nabila Mazouni-Gaertner, Yannick Gueguen, Alain Lo Yat, Corinne Belliard, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
0106 biological sciences, Biomineralization, Pacific ocean, 010504 meteorology & atmospheric sciences, Bioenergetics, Bioenergetic, French Polynesia, Context (language use), Aquatic Science, engineering.material, Oceanography, 01 natural sciences, Acclimatization, chemistry.chemical_compound, Pearl oyster, 14. Life underwater, Global change, 0105 earth and related environmental sciences, biology, Ecology, 010604 marine biology & hydrobiology, Pinctada margaritifera, Ocean acidification, Aquatic animal, biology.organism_classification, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, chemistry, 13. Climate action, Carbon dioxide, engineering, [SDV.EE.BIO]Life Sciences [q-bio]/Ecology, environment/Bioclimatology, Pearl
Abstract

International audience; The pearl culture is one of the most lucrative aquacultures worldwide. In many South Pacific areas, it depends on the exploitation of the pearl oyster Pinctada margaritifera and relies entirely on the environmental conditions encountered in the lagoon. In this context, assessing the impact of climatic stressors, such as global warming and ocean acidification, on the functionality of the resource in terms of renewal and exploitation is fundamental. In this study, we experimentally addressed the impact of temperature (22, 26, 30 and 34 °C) and partial pressure of carbon dioxide pCO2 (294, 763 and 2485 μatm) on the biomineralization and metabolic capabilities of pearl oysters. While the energy metabolism was strongly dependent on temperature, results showed its independence from pCO2 levels; no interaction between temperature and pCO2 was revealed. The energy metabolism, ingestion, oxygen consumption and, hence, the scope for growth (SFG) were maximised at 30 °C and dramatically fell at 34 °C. Biomineralization was examined through the expression measurement of nine mantle's genes coding for shell matrix proteins involved in the formation of calcitic prisms and/or nacreous shell structures; significant changes were recorded for four of the nine (Pmarg-Nacrein A1, Pmarg-MRNP34, Pmarg-Prismalin 14 and Pmarg-Aspein). These changes showed that the maximum and minimum expression of these genes was at 26 and 34 °C, respectively. Surprisingly, the modelled thermal optimum for biomineralization (ranging between 21.5 and 26.5 °C) and somatic growth and reproduction (28.7 °C) appeared to be significantly different. Finally, the responses to high temperatures were contextualised with the Intergovernmental Panel on Climate Change (IPCC) projections, which highlighted that pearl oyster stocks and cultures would be severely threatened in the next decade

Published
2016

32. An updated assessment of Symbiodinium that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B

Author

Héloïse Rouzé, Gaël J Lecellier, Denis Saulnier, Serge Planes, Yannick Gueguen, Herman H Wirshing, and Véronique Berteaux-Lecellier

Subjects
fungi, technology, industry, and agriculture, natural sciences, biochemical phenomena, metabolism, and nutrition, geographic locations
Abstract

The adaptative bleaching hypothesis (ABH) states that depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to “switch” or “shuffle” their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community, and, thus, contribute to the coral’s overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations, and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional conventional molecular methods, to assess the presence of low-abundance (background) Symbiodinium. Similar to other studies, each coral species exhibited a strong specificity to a particular clade, irrespective of the environment. In addition, however, each of the five species harboured at least one additional Symbiodinium clade, among clades A-D, at background levels. Unexpectedly, and for the first time in French Polynesia, clade B was detected as a coral symbiont. These results increase the number of known coral-Symbiodinium associations from corals found in French Polynesia, and likely indicate an underestimation of the ability of the corals in this region to associate with and/or “shuffle” different Symbiodinium clades. Altogether our data suggest that corals from French Polynesia may manage a trade-off between optimizing symbioses with a specific Symbiodinium clade(s), and maintaining associations with particular background clades that may play a role in the ability of corals to respond to environmental change.

Published
2016
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33. Efficient and long-lasting protection against the pacific oyster mortality syndrome through antiviral immune priming

Author

Bruno Petton, Guillaume Mitta, Philippe Haffner, Maxime Lafont, Jeremie Vidal-Dupiol, Agnès Vergnes, Julien de Lorgeril, Benjamin Gourbal, Caroline Montagnani, Yannick Gueguen, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), and Daniel Montero

Subjects
Oyster, Context (language use), Aquatic Science, ACTI, 03 medical and health sciences, Immune system, Immunity, biology.animal, Environmental Chemistry, 14. Life underwater, priming, 030304 developmental biology, oyster, 0303 health sciences, Innate immune system, OsHV-1, biology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], food and beverages, 04 agricultural and veterinary sciences, General Medicine, Pacific oyster, biology.organism_classification, antiviral, Immunology, 040102 fisheries, 0401 agriculture, forestry, and fisheries, Crassostrea, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Priming (psychology)
Abstract

International audience; The major economic and environmental consequences of recurring mortalities affecting the Pacific oyster Crassostrea gigas have initiated many research projects aiming at understanding these phenomena. The solutions anticipated to deal with these mortalities are mainly based on mass selection breeding programs but preventive treatments are still lacking. However, over the last decade, studies have been accumulating revealing the adaptive capabilities of innate immunity, the only component of defense mechanisms in invertebrates. Numerous findings have shown that a wide range of invertebrates can develop innate immune memory (also called immune priming) leading to improved survival during a second encounter with a pathogen. In this context, we undertook to study the possibilities of acting against mortalities by stimulating immune capacities of oysters.In the present study, we show that the exposure of oyster juveniles to an immunostimulant (a viral mimic called poly (I: C)) can lead to enhanced survival capacities (up to 100%) following OsHV-1 infection or during a mortality episode in the field. That protection is specific to viral protection as poly(I:C) fails to protect oyster against a pathogenic bacteria. We also show that this priming phenomenon is durable as it can last more than 4 months suggesting for the first time the existence of mechanisms of immune memory in this invertebrate species. Finally, analysis of the molecular pathways underlying that protection using dual RNAseq, revealed that priming was based on the triggering of a strong and sustained antiviral response limiting replication of the virus, thus allowing the protection of oysters on the long term. Altogether these results bring new insights into the oyster capacities to build an innate immune memory, its adaptive capacities and provide a platform to further explore novel strategies to help mitigate disease threats upon marine bivalves.

Published
2019

34. Integrated management of pearl culture in French Polynesia in the context of global change: synopsis of existing results

Author

Cédrik Lo, Yannick Gueguen, Nabila Gaertner-Mazouni, Gilles Le Moullac, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Direction des Ressources Marines et Minières, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, French Polynesia, Context (language use), Societal Dimensions, Aquatic Science, engineering.material, Oceanography, 01 natural sciences, Pinctada margaritifera, Environmental protection, Political science, 14. Life underwater, Global change, Integrated management, 0105 earth and related environmental sciences, business.industry, 010604 marine biology & hydrobiology, Scale (chemistry), Corporate governance, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Environmental resource management, Work (electrical), Pearl culture, Sustainability, engineering, business, Pearl, Pearl culture - Global change - French Polynesia - Pinctada margaritifera
Abstract

International audience; The paper presents a state of the art on knowledge of the black pearl oyster aquaculture at the scale of french Polynesia. lt also introduces the main results obtained throughout the multi-partners POLYPERL project. The goal of this project was to develop an integrated and participative action-research of thepearl oyster culture system, focusing on the envirorunental, technological, economical and societal dimensions impacting the industry. The research proposed ranges from the undentanding of biological phenomena of the production system to socio-economic aspects and governance of the industry,taking into account the management of anthropogenic, climate and health risks. we lntroduce here the different papers from the POLYPERL project that are compiled in this volume of ECSS dealing with recent scientific work that can contribute to sustainability of the pearl industry ln French Polynesia.

Published
2016

35. Bacterial community characterization of water and intestine of the shrimp Litopenaeus stylirostris in a biofloc system

Author

Denis Saulnier, Fabien Pierrat, Kevin Magré, Bénédicte Lorgeoux, David Piquemal, Emilie Cardona, Florian Noguier, Yannick Gueguen, Lagons, Ecosystèmes et Aquaculture Durable de Nouvelle Calédonie (LEADNC), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), ACOBIOM, Unité de recherche Lagons, Ecosystèmes et Aquaculture Durable en Nouvelle Calédonie, Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD)

Subjects
Chlorophyll, 0301 basic medicine, Aquaculture, Water column, RNA, Ribosomal, 16S, Ammonium Compounds, Culture environment, SPECTROSCOPY, CRYSTAL, biology, Viscosity, Ecology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Microbiota, High-Throughput Nucleotide Sequencing, MODULUS, Biodiversity, 04 agricultural and veterinary sciences, Hydrogen-Ion Concentration, Creep, Bacterial communities, 6. Clean water, Shrimp, Intestines, Clear sea water, Fresnoite, CRYSTALLIZATION, Water Microbiology, Research Article, Biofloc, Microbiology (medical), Penaeidae, Nitrogen Dioxide, Environment, Microbiology, 03 medical and health sciences, BATISI2O7, Animals, Seawater, 14. Life underwater, Shellfish, Detritus, Bacteria, Base Sequence, business.industry, Chlorophyll A, FRESNOITE GLASS, fungi, Water, biology.organism_classification, Elasticity, 030104 developmental biology, Microbial population biology, SILICATE-GLASSES, 040102 fisheries, TIO2, 0401 agriculture, forestry, and fisheries, Glass, Water quality, business
Abstract

International audience; Background: Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Results: Analyses of the bacterial community identified in water from BFT and " clear seawater " (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. Conclusion: This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.

Published
2016

36. Antimicrobial peptides in marine invertebrate health and disease

Author

Paulina Schmitt, Rafael Diego Rosa, Evelyne Bachère, Cairé Barreto, Delphine Destoumieux-Garzón, Guillaume Mitta, Yannick Gueguen, Jeremie Vidal-Dupiol, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Pontificia Universidad Católica de Valparaíso (PUCV), Federal University of Santa Catarina, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), and Institut de Recherche pour le Développement (IRD)

Subjects
0301 basic medicine, invertebrate immunity, abiotic stress, Invertebrate immunity, Antimicrobial peptides, Context (language use), environmental science, General Biochemistry, Genetics and Molecular Biology, immunology, resistance, 03 medical and health sciences, Anti-Infective Agents, Penaeidae, Aquaculture, Animals, microbiology Keywords: invertebrate immunity, 14. Life underwater, vibrio, Mollusca, biology, business.industry, Ecology, Aquatic animal, Articles, Marine invertebrates, biology.organism_classification, Invertebrates, Shrimp, 030104 developmental biology, polymicrobial disease, Interaction with host, [SDE]Environmental Sciences, immune suppression, Subject Areas: biochemistry, General Agricultural and Biological Sciences, business, Antimicrobial Cationic Peptides
Abstract

Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as ‘marine invertebrates’. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context.This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

Published
2016

37. Effect of electrolysis treatment on the biomineralization capacities of pearl oyster Pinctada margaritifera juveniles

Author

Yannick Gueguen, Philippe Cabral, Cédrik Lo, Corinne Belliard, Chin-Long Ky, Denis Schneider, Julie Fievet, Oïhana Latchere, Stéphanie Dieu, Denis Saulnier, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Direction des Ressources Marines et Minières, Espace Bleu, Gauguin's pearl Farm, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
0106 biological sciences, 0301 basic medicine, Biomineralization, Aquatic Science, Oceanography, 01 natural sciences, Electrolysis, law.invention, Pinctada margaritifera, 03 medical and health sciences, Animal science, law, Pearl oyster, 14. Life underwater, Growth rate, Mantle (mollusc), Shellfish, biology, Ecology, 010604 marine biology & hydrobiology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Aquatic animal, biology.organism_classification, Hatchery, 030104 developmental biology, Gene expression
Abstract

International audience; The present study investigated the effect of electrolysis on the biomineralization capacities of juveniles of the mollusk Pinctada argaritifera for the first time. Size-selected individuals from two groups, “Medium” and “Large”, from a multi-parental family produced in a hatchery system were subjected to electrolysis under a low voltage current over a nine-week experimental period. The growth of the juveniles was individually monitored and assessed weekly by wet weight and shell height measurements. At the end of the experiment, mantle tissue was sampled for biomineralization-related gene expression analysis. Electrolysis significantly increased pearl oyster growth in terms of shell height and wet weight for Large juveniles from the 5th and the 2nd week, respectively, until the end of the experiment. However, differences were only significant for Medium individuals from the 7th week for shell height and from the 9th week for wet weight. Furthermore, transcriptional analysis of six known biomineralization genes coding for shell matrix proteins of calcitic prisms and/or nacreous shell structures revealed that five were significantly overexpressed in the mantle mineralizing tissue under electrolysis: three in common between the two size class groups and two that were expressed exclusively in one or the other group. Finally, we found no statistical difference of the shell thickness ratio between individuals undergoing electrolysis and control conditions. Taken together, our results indicate, for the first time in a calcifying marine organism, that electrolysis influences molecular mechanisms involved in biomineralization and may stimulate some parameters of pearl oyster growth rate.

Published
2016

38. Identification of genes associated with shell color in the black-lipped pearl oyster, Pinctada margaritifera

Author

Yannick Gueguen, Sarah Lemer, Serge Planes, Denis Saulnier, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Université des Antilles (UA)-Institut d'écologie et environnement-Université de la Nouvelle-Calédonie (UNC)-Université de la Polynésie Française (UPF)-Université de La Réunion (UR)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Université des Antilles et de la Guyane (UAG)-Institut de Recherche pour le Développement (IRD)

Subjects
0106 biological sciences, Biomineralization, Candidate gene, Color, 010603 evolutionary biology, 01 natural sciences, 03 medical and health sciences, Differential expression, Genetics, Animals, Pinctada, Nacre, Gene, Margaritifera, 030304 developmental biology, Expressed Sequence Tags, 0303 health sciences, Expressed sequence tag, biology, Pigmentation, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Pinctada margaritifera, biology.organism_classification, Phenotype, Gene Expression Regulation, Suppression subtractive hybridization, Pearl, Albino, Biotechnology, Research Article
Abstract

Background Color polymorphism in the nacre of pteriomorphian bivalves is of great interest for the pearl culture industry. The nacreous layer of the Polynesian black-lipped pearl oyster Pinctada margaritifera exhibits a large array of color variation among individuals including reflections of blue, green, yellow and pink in all possible gradients. Although the heritability of nacre color variation patterns has been demonstrated by experimental crossing, little is known about the genes involved in these patterns. In this study, we identify a set of genes differentially expressed among extreme color phenotypes of P. margaritifera using a suppressive and subtractive hybridization (SSH) method comparing black phenotypes with full and half albino individuals. Results Out of the 358 and 346 expressed sequence tags (ESTs) obtained by conducting two SSH libraries respectively, the expression patterns of 37 genes were tested with a real-time quantitative PCR (RT-qPCR) approach by pooling five individuals of each phenotype. The expression of 11 genes was subsequently estimated for each individual in order to detect inter-individual variation. Our results suggest that the color of the nacre is partially under the influence of genes involved in the biomineralization of the calcitic layer. A few genes involved in the formation of the aragonite tablets of the nacre layer and in the biosynthesis chain of melanin also showed differential expression patterns. Finally, high variability in gene expression levels were observed within the black phenotypes. Conclusions Our results revealed that three main genetic processes were involved in color polymorphisms: the biomineralization of the nacreous and calcitic layers and the synthesis of pigments such as melanin, suggesting that color polymorphism takes place at different levels in the shell structure. The high variability of gene expression found within black phenotypes suggests that the present work should serve as a basis for future studies exploring more thoroughly the expression patterns of candidate genes within black phenotypes with different dominant iridescent colors. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1776-x) contains supplementary material, which is available to authorized users.

Published
2015

39. Yes, it turns: experimental evidence of pearl rotation during its formation

Author

Yann Czorlich, Didier Defay, Gilles Le Moullac, Pierre Lyonnard, Max Mastail, Yannick Gueguen, Hubert Bari, Damien Marigliano, Sébastien Chabrier, Cédrik Lo, Bruno Le Tohic, Jean-Pierre Gauthier, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Direction des Ressources Marines, Géopôle du Pacifique Sud (GePaSUD), Université de la Polynésie Française (UPF), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Direction des Ressources Marines (DRM), Ministère de l'économie et des finances, Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Université de la Polynésie Française (UPF), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
Oyster, Biology (whole organism) environmental science/computational biology/biophysics pearl oyster, 98702 Faa'a, BP 6570, Biominéralisation, 03 medical and health sciences, Paleontology, biology.animal, lcsh:Science, 030304 developmental biology, Physics, 0303 health sciences, Multidisciplinary, biology, Ecology, Huître perlière, Pearl oyster, Biology (Whole Organism), Perliculture, 04 agricultural and veterinary sciences, biomineralization, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, pearl rotation, 040102 fisheries, 0401 agriculture, forestry, and fisheries, lcsh:Q, pearl oyster, Tahiti, biomineralization laboratoire GEPASUD, Research Article
Abstract

Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a minimum of 40 days post-grafting and continues until the pearl harvest. We measured a mean angular speed of 1.27° min −1 calculated for four different oysters. Rotation variability was observed among oysters and may be correlated to pearl shape and defects. Nature's ability to generate so amazingly complex structures like a pearl has delivered one of its secrets.

Published
2015

40. Effect of temperature, food availability, and estradiol injection on gametogenesis and gender in the pearl oyster Pinctada margaritifera

Author

Vaihiti, Teaniniuraitemoana, Maxime, Leprêtre, Peva, Levy, Vincent, Vanaa, Sophie, Parrad, Nabila, Gaertner-Mazouni, Yannick, Gueguen, Arnaud, Huvet, and Gilles, Le Moullac

Subjects
Male, Estradiol, Food, Temperature, Animals, Gene Expression Regulation, Developmental, Female, Pinctada, RNA, Messenger, Sex Ratio, Sex Determination Processes, Gametogenesis
Abstract

The black-lip pearl oyster Pinctada margaritifera is a protandrous hermaphrodite species. Its economic value has led to the development of controlled hatchery reproduction techniques, although many aspects remain to be optimized. In order to understand reproductive mechanisms and their controlling factors, two independent experiments were designed to test hypotheses of gametogenesis and sex ratio control by environmental and hormonal factors. In one, pearl oysters were exposed under controlled conditions at different combinations of temperature (24 and 28°C) and food level (10,000 and 40,000 cells mL(-1) ); whereas in the other, pearl oysters were conditioned under natural conditions into the lagoon and subjected to successive 17β-estradiol injections (100 μg per injection). Gametogenesis and sex ratio were assessed by histology for each treatment. In parallel, mRNA expressions of nine marker genes of the sexual pathway (pmarg-foxl2, pmarg-c43476, pmarg-c45042, pmarg-c19309, pmarg-c54338, pmarg-vit6, pmarg-zglp1, pmarg-dmrt, and pmarg-fem1-like) were investigated. Maximum maturation was observed in the treatment combining the highest temperature (28°C) and the highest microalgae concentration (40,000 cells mL(-1) ), where the female sex tended to be maintained. Injection of 17β-estradiol induced a significant increase of undetermined stage proportion 2 weeks after the final injection. These results suggest that gametogenesis and gender in adult pearl oysters can be controlled by environmental factors and estrogens. While there were no significant effects on relative gene expression, the 3-gene-pair expression ratio model of the sexual pathway of P. margaritifera, suggest a probable dominance of genetic sex determinism without excluding a mixed sex determination mode (genetic + environmental). J. Exp. Zool. 325A:13-24, 2016. © 2015 Wiley Periodicals, Inc.

Published
2015

41. Relative contribution of natural productivity and compound feed to tissue growth in blue shrimp (Litopenaeus stylirostris) reared in biofloc: Assessment by C and N stable isotope ratios and effect on key digestive enzymes

Author

Emilie Cardona, Pierre Richard, Gaël Guillou, Denis Saulnier, Liet Chim, Claire Geffroy, Bénédicte Lorgeoux, Yannick Gueguen, Unité de recherche Lagons, Ecosystèmes et Aquaculture Durable en Nouvelle Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre Océanologique du Pacifique (COP), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Interactions Hôtes-Pathogènes-Environnements (IHPE), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD)

Subjects
animal structures, Biomass, Aquatic Science, Biology, 03 medical and health sciences, Fish meal, Digestive enzyme activities, 14. Life underwater, Food science, Soy protein, 030304 developmental biology, 2. Zero hunger, chemistry.chemical_classification, 0303 health sciences, Stable isotope ratio, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, Digestive enzyme mRNA level, 04 agricultural and veterinary sciences, Litopenaeus stylirostris, Stable isotope, Shrimp, Fishery, Enzyme, Productivity (ecology), chemistry, 040102 fisheries, 0401 agriculture, forestry, and fisheries, Shrimps, Biofloc
Abstract

The aim of this study was to assess the relative contribution of natural productivity and compound food to the growth of the juvenile blue shrimp Litopenaeus stylirostris reared in a biofloc system. Two experiments were carried out based on the same protocol with three treatments: clear water with experimental diet (CW), biofloc with experimental diet (BF) and biofloc unfed (BU). Shrimp survival was significantly higher in biofloc rearing than in CW rearing. The contribution of the biofloc to shrimp diet was estimated through measurement of carbon and nitrogen stable isotope ratios in shrimp and food sources. Different isotopic compositions between feeds were obtained by feeding natural productivity with a mixture rich in fish meal and the shrimps with a pellet containing a high level of soy protein concentrate. Using a two source one-isotope mixing model, we found that the natural productivity of the biofloc system contributed to shrimp growth at a level of 39.8% and 36.9%, for C and N, respectively. The natural food consumed by the shrimps reared in the biofloc system resulted in higher gene expression (mRNA transcript abundance) and activities of two digestive enzymes in their digestive gland: α-amylase and trypsin. The growth of shrimp biomass reared in biofloc was, on average, 4.4 times that of those grown in clear water. Our results confirmed the best survival and promoted growth of shrimps using biofloc technology and highlighted the key role of the biofloc in the nutrition of rearing shrimps. Statement of relevance In this study, we have applied an original protocol to determine the respective contribution of natural productivity and artificial feeds on the alimentation of the juvenile blue shrimp L. stylirostris reared in biofloc system by using C and N natural stable isotope analysis. Moreover, we have compared, in shrimp digestive gland, the α-amylase and trypsin enzyme activities at biochemical and molecular levels for two different shrimp rearing systems, biofloc and clear water. In our knowledge, the use of molecular tool to study the influence of biofloc consumption on digest process of shrimp was never carried out. We think that our research is new and important to increase knowledge on biofloc topic.

Published
2015

42. Rearing effect of biofloc on antioxidant and antimicrobial transcriptional response in Litopenaeus stylirostris shrimp facing an experimental sub-lethal hydrogen peroxide stress

Author

Bénédicte Lorgeoux, Denis Saulnier, Liet Chim, Yannick Gueguen, Emilie Cardona, Centre Océanologique du Pacifique (COP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche Lagons, Ecosystèmes et Aquaculture Durable en Nouvelle Calédonie, Interactions Hôtes-Pathogènes-Environnements (IHPE), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD)

Subjects
Penaeidae, Antioxidant, animal structures, Transcription, Genetic, medicine.medical_treatment, Antimicrobial peptides, Aquaculture, Aquatic Science, medicine.disease_cause, Antioxidants, Superoxide dismutase, antimicrobial peptides, Anti-Infective Agents, Stress, Physiological, biofloc, antioxidant enzymes, shrimps, Gene expression, medicine, Environmental Chemistry, Animals, 14. Life underwater, Food science, biology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], fungi, General Medicine, Hydrogen Peroxide, biology.organism_classification, Shrimp, Biochemistry, Catalase, biology.protein, Antioxidant enzymes, Shrimps, Oxidative stress, Biofloc, Antimicrobial Cationic Peptides
Abstract

International audience; This study compares the antioxidant and antimicrobial transcriptional expression of blue shrimps reared according to two different systems, BioFloc Technology (BFT) and Clear sea Water (CW) and their differential responses when facing an experimental sublethal hydrogen peroxide stress. After 30 days of rearing, juvenile shrimps were exposed to H2O2 stress at a concentration of 30 ppm during 6 hours. The oxidative stress caused by H2O2 was examined in the digestive glands of the shrimp, in which antioxidant enzyme (AOE) and antimicrobial peptide (AMP) gene expression were analysed by quantitative real-time PCR. Results showed that rearing conditions did not affect the expression of genes encoding AOEs or AMPs. However, H2O2 stress induced a differential response in expression between shrimps from the two rearing treatments (BFT and CW). Comparative analysis of the expression profiles indicates that catalase transcripts were significantly upregulated by H2O2 stress for BFT shrimps while no change was observed for CW shrimps. In contrast, H2O2 caused down-regulation of superoxide dismutase and glutathione transferase transcripts and of the three AMP transcripts studied (penaeidin 2 and 3, and crustin) for CW shrimps, while no effect was observed on BFT shrimp transcript levels. These results suggested that BFT shrimps maintained antioxidant and AMP responses after stress and therefore can effectively protect their cells against oxidative stress, while CW shrimp immune competence seems to decrease after stress

Published
2015

43. Recombinant expression and anti-microbial activity of anti-lipopolysaccharide factor (ALF) from the black tiger shrimp

Author

Evelyne Bachère, Yannick Gueguen, Sirawut Klinbunga, Bernard Romestand, Michael Marcos, Kunlaya Somboonwiwat, Guy Moulin, Anchalee Tassanakajon, André Aumelas, and Hélène Boze

Subjects
0303 health sciences, biology, Immunology, 04 agricultural and veterinary sciences, biology.organism_classification, Vibrio, Yeast, Shrimp, Microbiology, law.invention, Penaeus monodon, Pichia pastoris, 03 medical and health sciences, Transformation (genetics), law, 040102 fisheries, Recombinant DNA, 0401 agriculture, forestry, and fisheries, 14. Life underwater, Bacteria, 030304 developmental biology, Developmental Biology
Abstract

Anti-lipopolysaccharide factors (ALFs), originally characterized from horseshoe crabs, have been recently identified from hemocytes of the black tiger shrimp, Penaeus monodon, by a genomic approach. In order to characterize the properties and biological activities of this immune effector in shrimp, ALFPm3, the most abundant isoform found in P. monodon, was expressed in the yeast Pichia pastoris. Large-scale production in fermentor provided 262 mg/l of recombinant ALFPm3 which was purified to homogeneity by single chromatography step on expanded-bed Streamline SP6XL. The rALFPm3 was further characterized in terms of N-terminal sequencing and mass spectrometry. Anti-microbial assays demonstrated that rALFPm3 has a broad spectrum of anti-fungal properties against filamentous fungi, and anti-bacterial activities against both Gram-positive and Gram-negative bacteria, associated with a bactericidal effect. Interestingly, rALFPm3 is highly efficient against various Vibrio species including strains pathogenic for shrimp. Finally, a synthetic peptide corresponding to a part of the putative LPS-binding site of ALFPm3 was shown to display activities mainly directed against Gram-positive bacteria indicating the involvement of the full molecule to the anti-microbial activity for Gram-negative bacteria.

Published
2005

44. Insights into the anti-microbial defense of marine invertebrates: the penaeid shrimps and the oyster Crassostrea gigas

Author

Julien Garnier, Yannick Gueguen, Bernard Romestand, Julien de Lorgeril, Marcelo Gonzalez, and Evelyne Bachère

Subjects
Models, Molecular, Oyster, Hemocytes, Immunology, Immune system, Penaeidae, Immunity, biology.animal, Animals, Immunology and Allergy, Genetics, Innate immune system, biology, Effector, fungi, Models, Immunological, Marine invertebrates, biology.organism_classification, Ostreidae, Immunity, Innate, Hematopoiesis, Shrimp, Fishery, Gene Expression Regulation, Crassostrea, Antimicrobial Cationic Peptides
Abstract

Research on innate immunity of the penaeid shrimps and the oyster Crassostrea gigas is motivated greatly by economical necessities. Indeed, the aquaculture of these organisms is now limited by the development of infectious diseases. Studying anti-microbial peptides/proteins (AMPs), which are effector molecules of the host defense, is particularly attractive not only for progressing basic knowledge on immunity but also because they offer various possible applications for disease management in aquaculture. AMPs are explored with a global approach,considering their structure, properties, function, gene expression, and tissue distribution during the response to infections. In shrimp, investigations of the penaeidins, which are constitutively expressed peptides, have highlighted the importance of hemocytes and hematopoiesis as major elements of the immune response, providing both local and systemic reactions. The activation of hematopoiesis must be regarded as a regulatory way for the expression and distribution of constitutively expressed immune effectors. As complementary approaches, genomics and gene profiling are promising to deepen our understanding of the anti-microbial defense of the oyster and the shrimp. However, real progress will depend also on the characterization of hemocyte lineages and hematopoiesis of these marine invertebrates as well as on the ontogenesis of their immune systems.

Published
2004

45. Involvement of penaeidins in defense reactions of the shrimp Litopenaeus stylirostris to a pathogenic vibrio

Author

Marcelo Muñoz, Evelyne Bachère, Denis Saulnier, Julien Garnier, Yannick Gueguen, Franck Vandenbulcke, and Philippe Bulet

Subjects
Gill, animal structures, Agglutination, Molecular Sequence Data, Biology, Microbiology, Cellular and Molecular Neuroscience, Immune system, Anti-Infective Agents, Penaeidae, Animals, Protein Isoforms, Amino Acid Sequence, Molecular Biology, In Situ Hybridization, Vibrio, Pharmacology, Base Sequence, fungi, Proteins, Chemotaxis, Cell Biology, Antimicrobial, biology.organism_classification, Crustacean, Shrimp, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Vibrio Infections, Molecular Medicine, Peptides, Sequence Alignment, Bacteria
Abstract

The present study reports for the first time the involvement of an antimicrobial peptide in the defense reactions of a shrimp infected by a pathogenic Vibrio, Vibrio penaeicida. New members of the penaeidin family were characterized in the shrimp Litopenaeus stylirostris by RT-PCR and RACE-PCR from hemocyte total RNAs, and by mass spectrometry detection and immunolocalization of mature peptides in shrimp hemocytes. In infected shrimps, bacteria and penaeidin distribution colocalized in the gills and the lymphoid organ that represented the main infected sites. Moreover, the shrimp immune response to infection involved massive hemocyte recruitment to infection sites where released penaeidin may participate in the isolation and elimination of the bacteria, We show that the ability of the shrimps to circumvent shrimp infections is closely related to a recovery phase based on the hematopoietic process.

Published
2004

46. Influence of farmed pearl oysters and associated biofouling communities on nutrient regeneration in lagoons of French Polynesia

Author

Élise Lacoste, Gilles Le Moullac, Yannick Gueguen, Manaarii Sham Koua, Nabila Gaertner-Mazouni, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Génétique et évolution des interactions hôtes-parasites, Département génétique, interactions et évolution des génomes [LBBE] (GINSENG), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Centre Océanologique du Pacifique (COP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Centre Océanol. Pacifique, Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), and Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)

Subjects
Nutrient cycle, Biofouling, [SDV]Life Sciences [q-bio], SH1-691, Management, Monitoring, Policy and Law, Aquatic Science, engineering.material, Aquaculture impact, Nutrient flux, Water column, Nutrient, Aquaculture. Fisheries. Angling, Pearl oysters, Ecosystem, 14. Life underwater, QH540-549.5, ComputingMilieux_MISCELLANEOUS, Water Science and Technology, Trophic level, Ecology, fungi, food and beverages, Plankton, eye diseases, engineering, Environmental science, Pearl
Abstract

Bivalve cultivation can significantly contribute to nutrient cycling in semi-enclosed ecosystems. We investigated the influence of suspended pearl oyster culture on nutrient regener- ation in the water column of 3 oligotrophic lagoons in French Polynesia. The aim of this first study performed in a tropical area was to assess the seasonal variability of nutrient fluxes and to quantify the contribution of biofouling communities. In situ metabolic enclosure systems were used to measure nutrient uptake or release by 'cultivation units' (i.e. 4 pearl oysters with or without asso- ciated biofouling). In all 3 study lagoons (Tahiti, Mangareva, Ahe), nutrient fluxes produced by pearl oyster and associated biofouling communities (CR units) were 4- to 6-fold higher than those measured for cleaned pearl oysters. CR units can release dissolved inorganic nitrogen and soluble reactive phosphorus in the water column at a rate of 200 and 50 µmol h �1 , respectively. Trophic level and composition of biofouling communities may explain the variations of fluxes observed between the different islands. At the pearl farm scale (Ahe), pearl oyster long-lines may supply 70% of the inorganic nitrogen demand for primary production, with biofouling communities accounting for 60% of the total nutrient release. Pearl oyster culture enhances nutrient availability and alters stoichiometry, which can strongly modify the dynamics of the planktonic ecosystem.

Published
2014

47. A pearl of a partnership

Author

Yannick Gueguen, Mazouni, Nabila, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), and Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)

Subjects
Emplois, Perles de culture, Polynésie française, Economie, French Polynesia, Jobs, Economy, Pearl farming, [SHS.ECO]Humanities and Social Sciences/Economics and Finance
Abstract

International audience; Pearl farming is essential to the economy of French Polynesia, generating thousands of jobs for the islands. What are the main concerns for the current state of pearl farming in the region ?

Published
2014

48. Gonad transcriptome analysis of pearl oyster Pinctada margaritifera: identification of potential sex differentiation and sex determining genes

Author

Gilles Le Moullac, Arnaud Huvet, Christophe Klopp, Nabila Gaertner-Mazouni, Vaihiti Teaniniuraitemoana, Yannick Gueguen, Emeline Lhuillier, Peva Levy, Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de Biométrie et Intelligence Artificielle (UBIA), Institut National de la Recherche Agronomique (INRA), GeT PlaGe, Genotoul, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Centre Océanol. Pacifique, Le Moullac, Gilles, Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Génome et Transcriptome - Plateforme Génomique ( GeT-PlaGe), Plateforme Génome & Transcriptome (GET), Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR 'PolyPerl' project [ANR-11-AGRO-006], la Delegation a la Recherche de Polynesie francaise, ANR-11-AGRO-0006,POLYPERL,Gestion intégrée et adaptation de la perliculture en Polynésie française dans le contexte du changement global : approche environnementale, économique et sociale(2011), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité de Biométrie et Intelligence Artificielle (ancêtre de MIAT) (UBIA), Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
Male, 0106 biological sciences, Sex Determination Analysis, gamétogenèse, [SDV]Life Sciences [q-bio], 01 natural sciences, Gametogenesis, Pinctada margaritifera, Transcriptome, Differential expression, Sex determinism, INDEL Mutation, Hermaphrodite, Margaritifera, ComputingMilieux_MISCELLANEOUS, Genetics, 0303 health sciences, biology, OS, medicine.anatomical_structure, expression différentielle, Female, Research Article, Biotechnology, Gonad, Molecular Sequence Data, pinctada margaritifera, Polymorphism, Single Nucleotide, 010603 evolutionary biology, 03 medical and health sciences, déterminisme du sexe, medicine, Animals, Amino Acid Sequence, Pinctada, 14. Life underwater, Gonads, 030304 developmental biology, Sexual differentiation, Gene Expression Profiling, Molecular Sequence Annotation, Sequence Analysis, DNA, Sex Determination Processes, biology.organism_classification, Sexual dimorphism, Gene Ontology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, transcriptome, Microsatellite Repeats
Abstract

Background Black pearl farming is based on culture of the blacklip pearl oyster Pinctada margaritifera (Mollusca, lophotrochozoa), a protandrous hermaphrodite species. At first maturation, all individuals are males. The female sex appears progressively from two years old, which represents a limitation for broodstock conditioning for aquaculture production. In marine mollusks displaying hermaphroditic features, data on sexual determinism and differentiation, including the molecular sex determining cascade, are scarce. To increase genomic resources and identify the molecular mechanisms whereby gene expression may act in the sexual dimorphism of P. margaritifera, we performed gonad transcriptome analysis. Results The gonad transcriptome of P. margaritifera was sequenced from several gonadic samples of males and females at different development stages, using a Next-Generation-Sequencing method and RNAseq technology. After Illumina sequencing, assembly and annotation, we obtained 70,147 contigs of which 62.2% shared homologies with existing protein sequences, and 9% showed functional annotation with Gene Ontology terms. Differential expression analysis identified 1,993 differentially expressed contigs between the different categories of gonads. Clustering methods of samples revealed that the sex explained most of the variation in gonad gene expression. K-means clustering of differentially expressed contigs showed 815 and 574 contigs were more expressed in male and female gonads, respectively. The analysis of these contigs revealed the presence of known specific genes coding for proteins involved in sex determinism and/or differentiation, such as dmrt and fem-1 like for males, or foxl2 and vitellogenin for females. The specific gene expression profiles of pmarg-fem1-like, pmarg-dmrt and pmarg-foxl2 in different reproductive stages (undetermined, sexual inversion and regression) suggest that these three genes are potentially involved in the sperm-oocyte switch in P. margaritifera. Conclusions The study provides a new transcriptomic tool to study reproduction in hermaphroditic marine mollusks. It identifies sex differentiation and potential sex determining genes in P. margaritifera, a protandrous hermaphrodite species. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-491) contains supplementary material, which is available to authorized users.

Published
2014

49. Characterization of two DNA polymerases from the hyperthermophilic euryarchaeonPyrococcus abyssi

Author

Yannick Gueguen, Jean-Luc Rolland, Jean-Paul Raffin, Jacques Dietrich, Didier Flament, Philippe Azam, Gisèle Le Romancer, and Odile Lecompte

Subjects
biology, DNA polymerase, DNA polymerase II, DNA replication, Processivity, biology.organism_classification, Biochemistry, DNA polymerase delta, Molecular biology, biology.protein, DNA polymerase I, DNA polymerase mu, Pyrococcus abyssi
Abstract

The complete genome sequence of the hyperthermophilic archaeon Pyrococcus abyssi revealed the presence of a family B DNA polymerase (Pol I) and a family D DNA polymerase (Pol II). To extend our knowledge about euryarchaeal DNA polymerases, we cloned the genes encoding these two enzymes and expressed them in Escherichia coli. The DNA polymerases (Pol I and Pol II) were purified to homogeneity and characterized. Pol I had a molecular mass of approximately 90 kDa, as estimated by SDS/PAGE. The optimum pH and Mg(2+) concentration of Pol I were 8.5-9.0 and 3 mm, respectively. Pol II is composed of two subunits that are encoded by two genes arranged in tandem on the P. abyssi genome. We cloned these genes and purified the Pol II DNA polymerase from an E. coli strain coexpressing the cloned genes. The optimum pH and Mg(2+) concentration of Pol II were 6.5 and 15-20 mm, respectively. Both P. abyssi Pol I and Pol II have associated 3'-->5' exonuclease activity although the exonuclease motifs usually found in DNA polymerases are absent in the archaeal family D DNA polymerase sequences. Sequence analysis has revealed that the small subunit of family D DNA polymerase and the Mre11 nucleases belong to the calcineurin-like phosphoesterase superfamily and that residues involved in catalysis and metal coordination in the Mre11 nuclease three-dimensional structure are strictly conserved in both families. One hypothesis is that the phosphoesterase domain of the small subunit is responsible for the 3'-->5' exonuclease activity of family D DNA polymerase. These results increase our understanding of euryarchaeal DNA polymerases and are of importance to push forward the complete understanding of the DNA replication in P. abyssi.

Published
2001

50. Genetic and biochemical characterization of a short-chain alcohol dehydrogenase from the hyperthermophilic archaeonPyrococcus furiosus

Author

Servé W. M. Kengen, W.G.B. Voorhorst, J. van der Oost, A.C.M. Geerling, V. Wittenhorst, W.M. de Vos, and Yannick Gueguen

Subjects
chemistry.chemical_classification, biology, Operon, Alcohol oxidoreductase, biology.organism_classification, medicine.disease_cause, Biochemistry, chemistry, Oxidoreductase, Pyrococcus furiosus, biology.protein, Carbohydrate fermentation, medicine, Protein quaternary structure, Escherichia coli, Alcohol dehydrogenase
Abstract

The gene encoding a short-chain alcohol dehydrogenase, AdhA, has been identified in the hyperthermophilic archaeon Pyrococcus furiosus, as part of an operon that encodes two glycosyl hydrolases, the beta-glucosidase CelB and the endoglucanase LamA. The adhA gene was functionally expressed in Escherichia coli, and AdhA was subsequently purified to homogeneity. The quaternary structure of AdhA is a dimer of identical 26-kDa subunits. AdhA is an NADPH-dependent oxidoreductase that converts alcohols to the corresponding aldehydes/ketones and vice versa, with a rather broad substrate specificity. Maximal specific activities were observed with 2-pentanol (46 U x mg(-1)) and pyruvaldehyde (32 U x mg(-1)) in the oxidative and reductive reaction, respectively. AdhA has an optimal activity at 90 degrees C, at which temperature it has a half life of 22.5 h. The expression of the adhA gene in P. furiosus was demonstrated by activity measurements and immunoblot analysis of cell extracts. A role of this novel type of archaeal alcohol dehydrogenase in carbohydrate fermentation is discussed.

Published
2001

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