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3. Proteogenomic reconstruction of organ-specific metabolic networks in an environmental sentinel species, the amphipod Gammarus fossarum

Author

Koenig, Natacha, Baa-Puyoulet, Patrice, Lafont, Amélie, Lorenzo-Colina, Isis, Navratil, Vincent, Leprêtre, Maxime, Sugier, Kevin, Delorme, Nicolas, Garnero, Laura, Queau, Hervé, Gaillard, Jean-Charles, Kielbasa, Mélodie, Ayciriex, Sophie, Calevro, Federica, Chaumot, Arnaud, Charles, Hubert, Armengaud, Jean, Geffard, Olivier, and Degli Esposti, Davide

Published
2024
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4. Genomic analysis of the regulatory elements and links with intrinsic DNA structural properties in the shrunken genome of Buchnera

Author

Brinza Lilia, Calevro Federica, and Charles Hubert

Subjects
Buchnera aphidicola, Genome reduction, Transcription regulation, DNA-topology, Nucleoid associated proteins (NAPs), Biotechnology, TP248.13-248.65, Genetics, QH426-470
Abstract

Abstract Background Buchnera aphidicola is an obligate symbiotic bacterium, associated with most of the aphididae, whose genome has drastically shrunk during intracellular evolution. Gene regulation in Buchnera has been a matter of controversy in recent years as the combination of genomic information with the experimental results has been contradictory, refuting or arguing in favour of a functional and responsive transcription regulation in Buchnera. The goal of this study was to describe the gene transcription regulation capabilities of Buchnera based on the inventory of cis- and trans-regulators encoded in the genomes of five strains from different aphids (Acyrthosiphon pisum, Schizaphis graminum, Baizongia pistacea, Cinara cedri and Cinara tujafilina), as well as on the characterisation of some intrinsic structural properties of the DNA molecule in these bacteria. Results Interaction graph analysis shows that gene neighbourhoods are conserved between E. coli and Buchnera in structures called transcriptons, interactons and metabolons, indicating that selective pressures have acted on the evolution of transcriptional, protein-protein interaction and metabolic networks in Buchnera. The transcriptional regulatory network in Buchnera is composed of a few general DNA-topological regulators (Nucleoid Associated Proteins and topoisomerases), with the quasi-absence of any specific ones (except for multifunctional enzymes with a known gene expression regulatory role in Escherichia coli, such as AlaS, PepA and BolA, and the uncharacterized hypothetical regulators YchA and YrbA). The relative positioning of regulatory genes along the chromosome of Buchnera seems to have conserved its ancestral state, despite the genome erosion. Sigma-70 promoters with canonical thermodynamic sequence profiles were detected upstream of about 94% of the CDS of Buchnera in the different aphids. Based on Stress-Induced Duplex Destabilization (SIDD) measurements, unstable σ70 promoters were found specifically associated with the regulator and transporter genes. Conclusions This genomic analysis provides supporting evidence of a selection of functional regulatory structures and it has enabled us to propose hypotheses concerning possible links between these regulatory elements and the DNA-topology (i.e., supercoiling, curvature, flexibility and base-pair stability) in the regulation of gene expression in the shrunken genome of Buchnera.

Published
2013
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6. Structure and dynamics of the operon map of Buchnera aphidicola sp. strain APS

Author

Gautier Christian, Gaget Karen, Duport Gabrielle, Calevro Federica, Brinza Lilia, and Charles Hubert

Subjects
Biotechnology, TP248.13-248.65, Genetics, QH426-470
Abstract

Abstract Background Gene expression regulation is still poorly documented in bacteria with highly reduced genomes. Understanding the evolution and mechanisms underlying the regulation of gene transcription in Buchnera aphidicola, the primary endosymbiont of aphids, is expected both to enhance our understanding of this nutritionally based association and to provide an intriguing case-study of the evolution of gene expression regulation in a reduced bacterial genome. Results A Bayesian predictor was defined to infer the B. aphidicola transcription units, which were further validated using transcriptomic data and RT-PCR experiments. The characteristics of B. aphidicola predicted transcription units (TUs) were analyzed in order to evaluate the impact of operon map organization on the regulation of gene transcription. On average, B. aphidicola TUs contain more genes than those of E. coli. The global layout of B. aphidicola operon map was mainly shaped by the big reduction and the rearrangements events, which occurred at the early stage of the symbiosis. Our analysis suggests that this operon map may evolve further only by small reorganizations around the frontiers of B. aphidicola TUs, through promoter and/or terminator sequence modifications and/or by pseudogenization events. We also found that the need for specific transcription regulation exerts some pressure on gene conservation, but not on gene assembling in the operon map in Buchnera. Our analysis of the TUs spacing pointed out that a selection pressure is maintained on the length of the intergenic regions between divergent adjacent gene pairs. Conclusions B. aphidicola can seemingly only evolve towards a more polycistronic operon map. This implies that gene transcription regulation is probably subject to weak selection pressure in Buchnera conserving operons composed of genes with unrelated functions.

Published
2010
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7. Conservation of the links between gene transcription and chromosomal organization in the highly reduced genome of Buchnera aphidicola

Author

Febvay Gérard, Rahbé Yvan, Bernillon Jacques, Remond Didier, Calevro Federica, Viñuelas José, Fayard Jean-Michel, and Charles Hubert

Subjects
Biotechnology, TP248.13-248.65, Genetics, QH426-470
Abstract

Abstract Background Genomic studies on bacteria have clearly shown the existence of chromosomal organization as regards, for example, to gene localization, order and orientation. Moreover, transcriptomic analyses have demonstrated that, in free-living bacteria, gene transcription levels and chromosomal organization are mutually influenced. We have explored the possible conservation of relationships between mRNA abundances and chromosomal organization in the highly reduced genome of Buchnera aphidicola, the primary endosymbiont of the aphids, and a close relative to Escherichia coli. Results Using an oligonucleotide-based microarray, we normalized the transcriptomic data by genomic DNA signals in order to have access to inter-gene comparison data. Our analysis showed that mRNA abundances, gene organization (operon) and gene essentiality are correlated in Buchnera (i.e., the most expressed genes are essential genes organized in operons) whereas no link between mRNA abundances and gene strand bias was found. The effect of Buchnera genome evolution on gene expression levels has also been analysed in order to assess the constraints imposed by the obligate symbiosis with aphids, underlining the importance of some gene sets for the survival of the two partners. Finally, our results show the existence of spatial periodic transcriptional patterns in the genome of Buchnera. Conclusion Despite an important reduction in its genome size and an apparent decay of its capacity for regulating transcription, this work reveals a significant correlation between mRNA abundances and chromosomal organization of the aphid-symbiont Buchnera.

Published
2007
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8. Correction to: The genome sequence of the grape phylloxera provides insights into the evolution, adaptation, and invasion routes of an iconic pest

Author

Rispe, Claude, Legeai, Fabrice, Nabity, Paul D, Fernández, Rosa, Arora, Arinder K, Baa-Puyoulet, Patrice, Banfill, Celeste R, Bao, Leticia, Barberà, Miquel, Bouallègue, Maryem, Bretaudeau, Anthony, Brisson, Jennifer A, Calevro, Federica, Capy, Pierre, Catrice, Olivier, Chertemps, Thomas, Couture, Carole, Delière, Laurent, Douglas, Angela E, Dufault-Thompson, Keith, Escuer, Paula, Feng, Honglin, Forneck, Astrid, Gabaldón, Toni, Guigó, Roderic, Hilliou, Frédérique, Hinojosa-Alvarez, Silvia, Hsiao, Yi-min, Hudaverdian, Sylvie, Jacquin-Joly, Emmanuelle, James, Edward B, Johnston, Spencer, Joubard, Benjamin, Le Goff, Gaëlle, Le Trionnaire, Gaël, Librado, Pablo, Liu, Shanlin, Lombaert, Eric, Lu, Hsiao-ling, Maïbèche, Martine, Makni, Mohamed, Marcet-Houben, Marina, Martínez-Torres, David, Meslin, Camille, Montagné, Nicolas, Moran, Nancy A, Papura, Daciana, Parisot, Nicolas, Rahbé, Yvan, Lopes, Mélanie Ribeiro, Ripoll-Cladellas, Aida, Robin, Stéphanie, Roques, Céline, Roux, Pascale, Rozas, Julio, Sánchez-Gracia, Alejandro, Sánchez-Herrero, Jose F, Santesmasses, Didac, Scatoni, Iris, Serre, Rémy-Félix, Tang, Ming, Tian, Wenhua, Umina, Paul A, van Munster, Manuella, Vincent-Monégat, Carole, Wemmer, Joshua, Wilson, Alex CC, Zhang, Ying, Zhao, Chaoyang, Zhao, Jing, Zhao, Serena, Zhou, Xin, Delmotte, François, and Tagu, Denis

Subjects
Developmental Biology
Abstract

An amendment to this paper has been published and can be accessed via the original article.

Published
2020

9. The genome sequence of the grape phylloxera provides insights into the evolution, adaptation, and invasion routes of an iconic pest

Author

Rispe, Claude, Legeai, Fabrice, Nabity, Paul D, Fernández, Rosa, Arora, Arinder K, Baa-Puyoulet, Patrice, Banfill, Celeste R, Bao, Leticia, Barberà, Miquel, Bouallègue, Maryem, Bretaudeau, Anthony, Brisson, Jennifer A, Calevro, Federica, Capy, Pierre, Catrice, Olivier, Chertemps, Thomas, Couture, Carole, Delière, Laurent, Douglas, Angela E, Dufault-Thompson, Keith, Escuer, Paula, Feng, Honglin, Forneck, Astrid, Gabaldón, Toni, Guigó, Roderic, Hilliou, Frédérique, Hinojosa-Alvarez, Silvia, Hsiao, Yi-min, Hudaverdian, Sylvie, Jacquin-Joly, Emmanuelle, James, Edward B, Johnston, Spencer, Joubard, Benjamin, Le Goff, Gaëlle, Le Trionnaire, Gaël, Librado, Pablo, Liu, Shanlin, Lombaert, Eric, Lu, Hsiao-ling, Maïbèche, Martine, Makni, Mohamed, Marcet-Houben, Marina, Martínez-Torres, David, Meslin, Camille, Montagné, Nicolas, Moran, Nancy A, Papura, Daciana, Parisot, Nicolas, Rahbé, Yvan, Lopes, Mélanie Ribeiro, Ripoll-Cladellas, Aida, Robin, Stéphanie, Roques, Céline, Roux, Pascale, Rozas, Julio, Sánchez-Gracia, Alejandro, Sánchez-Herrero, Jose F, Santesmasses, Didac, Scatoni, Iris, Serre, Rémy-Félix, Tang, Ming, Tian, Wenhua, Umina, Paul A, van Munster, Manuella, Vincent-Monégat, Carole, Wemmer, Joshua, Wilson, Alex CC, Zhang, Ying, Zhao, Chaoyang, Zhao, Jing, Zhao, Serena, Zhou, Xin, Delmotte, François, and Tagu, Denis

Subjects
Biological Sciences, Genetics, Human Genome, Infection, Climate Action, Adaptation, Biological, Animal Distribution, Animals, Biological Evolution, Genome, Insect, Hemiptera, Introduced Species, Vitis, Arthropod genomes, Daktulosphaira vitifoliae, Gene duplications, Host plant interactions, Effectors, Biological invasions, Developmental Biology, Biological sciences
Abstract

BackgroundAlthough native to North America, the invasion of the aphid-like grape phylloxera Daktulosphaira vitifoliae across the globe altered the course of grape cultivation. For the past 150 years, viticulture relied on grafting-resistant North American Vitis species as rootstocks, thereby limiting genetic stocks tolerant to other stressors such as pathogens and climate change. Limited understanding of the insect genetics resulted in successive outbreaks across the globe when rootstocks failed. Here we report the 294-Mb genome of D. vitifoliae as a basic tool to understand host plant manipulation, nutritional endosymbiosis, and enhance global viticulture.ResultsUsing a combination of genome, RNA, and population resequencing, we found grape phylloxera showed high duplication rates since its common ancestor with aphids, but similarity in most metabolic genes, despite lacking obligate nutritional symbioses and feeding from parenchyma. Similarly, no enrichment occurred in development genes in relation to viviparity. However, phylloxera evolved > 2700 unique genes that resemble putative effectors and are active during feeding. Population sequencing revealed the global invasion began from the upper Mississippi River in North America, spread to Europe and from there to the rest of the world.ConclusionsThe grape phylloxera genome reveals genetic architecture relative to the evolution of nutritional endosymbiosis, viviparity, and herbivory. The extraordinary expansion in effector genes also suggests novel adaptations to plant feeding and how insects induce complex plant phenotypes, for instance galls. Finally, our understanding of the origin of this invasive species and its genome provide genetics resources to alleviate rootstock bottlenecks restricting the advancement of viticulture.

Published
2020

10. Sawfly genomes reveal evolutionary acquisitions that fostered the mega-radiation of parasitoid and eusocial Hymenoptera

Author

Oeyen, Jan Philip, Baa-Puyoulet, Patrice, Benoit, Joshua B, Beukeboom, Leo W, Bornberg-Bauer, Erich, Buttstedt, Anja, Calevro, Federica, Cash, Elizabeth I, Chao, Hsu, Charles, Hubert, Chen, Mei-Ju May, Childers, Christopher, Cridge, Andrew G, Dearden, Peter, Dinh, Huyen, Doddapaneni, Harsha Vardhan, Dolan, Amanda, Donath, Alexander, Dowling, Daniel, Dugan, Shannon, Duncan, Elizabeth, Elpidina, Elena N, Friedrich, Markus, Geuverink, Elzemiek, Gibson, Joshua D, Grath, Sonja, Grimmelikhuijzen, Cornelis JP, Große-Wilde, Ewald, Gudobba, Cameron, Han, Yi, Hansson, Bill S, Hauser, Frank, Hughes, Daniel ST, Ioannidis, Panagiotis, Jacquin-Joly, Emmanuelle, Jennings, Emily C, Jones, Jeffery W, Klasberg, Steffen, Lee, Sandra L, Lesný, Peter, Lovegrove, Mackenzie, Martin, Sebastian, Martynov, Alexander G, Mayer, Christoph, Montagné, Nicolas, Moris, Victoria C, Munoz-Torres, Monica, Murali, Shwetha Canchi, Muzny, Donna M, Oppert, Brenda, Parisot, Nicolas, Pauli, Thomas, Peters, Ralph S, Petersen, Malte, Pick, Christian, Persyn, Emma, Podsiadlowski, Lars, Poelchau, Monica F, Provataris, Panagiotis, Qu, Jiaxin, Reijnders, Maarten JMF, von Reumont, Björn Marcus, Rosendale, Andrew J, Simao, Felipe A, Skelly, John, Sotiropoulos, Alexandros G, Stahl, Aaron L, Sumitani, Megumi, Szuter, Elise M, Tidswell, Olivia, Tsitlakidis, Evangelos, Vedder, Lucia, Waterhouse, Robert M, Werren, John H, Wilbrandt, Jeanne, Worley, Kim C, Yamamoto, Daisuke S, van de Zande, Louis, Zdobnov, Evgeny M, Ziesmann, Tanja, Gibbs, Richard A, Richards, Stephen, Hatakeyama, Masatsugu, Misof, Bernhard, and Niehuis, Oliver

Subjects
Human Genome, Genetics, Life Below Water, Amino Acid Sequence, Animals, Conserved Sequence, DNA Transposable Elements, Female, Gene Dosage, Genetic Speciation, Genome, Insect, Glycoproteins, Herbivory, Host-Parasite Interactions, Hymenoptera, Immunity, Insect Proteins, Male, Multigene Family, Receptors, Odorant, Social Behavior, Vision, Ocular, hexamerin, major royal jelly protein, microsynteny, odorant receptor, opsin, phytophagy, Biochemistry and Cell Biology, Evolutionary Biology, Developmental Biology
Abstract

The tremendous diversity of Hymenoptera is commonly attributed to the evolution of parasitoidism in the last common ancestor of parasitoid sawflies (Orussidae) and wasp-waisted Hymenoptera (Apocrita). However, Apocrita and Orussidae differ dramatically in their species richness, indicating that the diversification of Apocrita was promoted by additional traits. These traits have remained elusive due to a paucity of sawfly genome sequences, in particular those of parasitoid sawflies. Here, we present comparative analyses of draft genomes of the primarily phytophagous sawfly Athalia rosae and the parasitoid sawfly Orussus abietinus. Our analyses revealed that the ancestral hymenopteran genome exhibited traits that were previously considered unique to eusocial Apocrita (e.g., low transposable element content and activity) and a wider gene repertoire than previously thought (e.g., genes for CO2 detection). Moreover, we discovered that Apocrita evolved a significantly larger array of odorant receptors than sawflies, which could be relevant to the remarkable diversification of Apocrita by enabling efficient detection and reliable identification of hosts.

Published
2020

12. Evolutionary novelty in the apoptotic pathway of aphids

Author

Lopes, Mélanie Ribeiro, Parisot, Nicolas, Gaget, Karen, Huygens, Cissy, Peignier, Sergio, Duport, Gabrielle, Orlans, Julien, Charles, Hubert, Baatsen, Pieter, Jousselin, Emmanuelle, Da Silva, Pedro, Hens, Korneel, Callaerts, Patrick, and Calevro, Federica

Published
2020

14. The transposable element-rich genome of the cereal pest Sitophilus oryzae

Author

Parisot, Nicolas, Vargas-Chávez, Carlos, Goubert, Clément, Baa-Puyoulet, Patrice, Balmand, Séverine, Beranger, Louis, Blanc, Caroline, Bonnamour, Aymeric, Boulesteix, Matthieu, Burlet, Nelly, Calevro, Federica, Callaerts, Patrick, Chancy, Théo, Charles, Hubert, Colella, Stefano, Da Silva Barbosa, André, Dell’Aglio, Elisa, Di Genova, Alex, Febvay, Gérard, Gabaldón, Toni, Galvão Ferrarini, Mariana, Gerber, Alexandra, Gillet, Benjamin, Hubley, Robert, Hughes, Sandrine, Jacquin-Joly, Emmanuelle, Maire, Justin, Marcet-Houben, Marina, Masson, Florent, Meslin, Camille, Montagné, Nicolas, Moya, Andrés, Ribeiro de Vasconcelos, Ana Tereza, Richard, Gautier, Rosen, Jeb, Sagot, Marie-France, Smit, Arian F. A., Storer, Jessica M., Vincent-Monegat, Carole, Vallier, Agnès, Vigneron, Aurélien, Zaidman-Rémy, Anna, Zamoum, Waël, Vieira, Cristina, Rebollo, Rita, Latorre, Amparo, and Heddi, Abdelaziz

Published
2021
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16. Comprehensive Annotation of Transcription Factors, Chromatin-Associated Factors, and Basal Transcription Machinery in the Pea Aphid, Acyrthosiphon Pisum, and Development of the Atfdb Database, a Resource for Studies of Transcriptional Regulation

Author

Parisot, Nicolas, primary, Ribeiro Lopes, Mélanie, additional, Peignier, Sergio, additional, Baa-Puyoulet, Patrice, additional, Charles, Hubert, additional, Calevro, Federica, additional, and Callaerts, Patrick, additional

Published
2024
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19. Discovery of an Insect Neuroactive Helix Ring Peptide from Ant Venom

Author

Barassé, Valentine, primary, Jouvensal, Laurence, additional, Boy, Guillaume, additional, Billet, Arnaud, additional, Ascoët, Steven, additional, Lefranc, Benjamin, additional, Leprince, Jérôme, additional, Dejean, Alain, additional, Lacotte, Virginie, additional, Rahioui, Isabelle, additional, Sivignon, Catherine, additional, Gaget, Karen, additional, Ribeiro Lopes, Mélanie, additional, Calevro, Federica, additional, Da Silva, Pedro, additional, Loth, Karine, additional, Paquet, Françoise, additional, Treilhou, Michel, additional, Bonnafé, Elsa, additional, and Touchard, Axel, additional

Published
2023
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20. Identification and organ-specific patterns of expression of two metallothioneins in the sentinel species Gammarus fossarum

Author

Esposti, Davide Degli, primary, Lalouette, Auréline, additional, Gaget, Karen, additional, Lepeule, Louveline, additional, Chaabi, Zineb, additional, Leprêtre, Maxime, additional, Espeyte, Anabelle, additional, Delorme, Nicolas, additional, Quéau, Hervé, additional, Garnero, Laura, additional, Calevro, Federica, additional, Chaumot, Arnaud, additional, and Geffard, Olivier, additional

Published
2023
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28. Ensemble Learning Based Gene Regulatory Network Inference.

Author

Peignier, Sergio, Sorin, Baptiste, and Calevro, Federica

Subjects
GENE regulatory networks, COMPUTATIONAL biology, SPACE exploration, GENETIC algorithms, MACHINE learning
Abstract

In the machine learning field, the technique known as ensemble learning aims at combining different base learners in order to increase the quality and the robustness of the predictions. Indeed, this approach has widely been applied to tackle, with success, real world problems from different domains, including computational biology. Nevertheless, despite their potential, ensembles combining results from different base learners have been understudied in the context of gene regulatory network inference. In this paper we applied genetic algorithms and frequent itemset mining, to design small but effective ensembles of gene regulatory network inference methods. These ensembles were evaluated and compared to well-established single and ensemble methods, on both real and synthetic datasets. Results showed that small ensembles, consisting of few but diverse base learners, enhance the exploration of the solution space, and compensate base learners biases, outperforming state-of-the-art methods. Results advocate for the use of such methods as gene regulatory network inference tools. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Aphid BCR4 Structure and Activity Uncover a New Defensin Peptide Superfamily

Author

Loth, Karine, primary, Parisot, Nicolas, additional, Paquet, Françoise, additional, Terrasson, Hugo, additional, Sivignon, Catherine, additional, Rahioui, Isabelle, additional, Ribeiro Lopes, Mélanie, additional, Gaget, Karen, additional, Duport, Gabrielle, additional, Delmas, Agnès F., additional, Aucagne, Vincent, additional, Heddi, Abdelaziz, additional, Calevro, Federica, additional, and da Silva, Pedro, additional

Published
2022
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30. From genomes to metabolism reconstruction: companion collections of databases to study symbiotic interactions between insects and their bacterial symbionts

Author

Baa-Puyoulet, Patrice, Parisot, Nicolas, Peignier, Sergio, Calevro, Federica, Charles, Hubert, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)

Subjects
[SDV]Life Sciences [q-bio], metabolism network, Database Development, BioCyc, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], ComputingMilieux_MISCELLANEOUS, Réseaux métaboliques réseaux génétiques
Abstract

International audience

Published
2022

33. The Di-Symbiotic Systems in the Aphids Sipha maydis and Periphyllus lyropictus Provide a Contrasting Picture of Recent Co-Obligate Nutritional Endosymbiosis in Aphids

Author

UCL - SST/ELI/ELIB - Biodiversity, Renoz, François, Ambroise, Jérôme, Bearzatto, Bertrand, Fakhour, Samir, Parisot, Nicolas, Ribeiro Lopes, Mélanie, Gala, Jean-Luc, Calevro, Federica, Hance, Thierry, UCL - SST/ELI/ELIB - Biodiversity, Renoz, François, Ambroise, Jérôme, Bearzatto, Bertrand, Fakhour, Samir, Parisot, Nicolas, Ribeiro Lopes, Mélanie, Gala, Jean-Luc, Calevro, Federica, and Hance, Thierry

Abstract

Dependence on multiple nutritional bacterial symbionts forming a metabolic unit has repeatedly evolved in many insect species that feed on nutritionally unbalanced diets such as plant sap. This is the case for aphids of the subfamilies Lachninae and Chaitophorinae, which have evolved di-symbiotic systems in which the ancient obligate nutritional symbiont Buchnera aphidicola is metabolically complemented by an additional nutritional symbiont acquired more recently. Deciphering how different symbionts integrate both metabolically and anatomically in such systems is crucial to understanding how complex nutritional symbiotic systems function and evolve. In this study, we sequenced and analyzed the genomes of the symbionts B. aphidicola and Serratia symbiotica associated with the Chaitophorinae aphids Sipha maydis and Periphyllus lyropictus. Our results show that, in these two species, B. aphidicola and S. symbiotica complement each other metabolically (and their hosts) for the biosynthesis of essential amino acids and vitamins, but with distinct metabolic reactions supported by each symbiont depending on the host species. Furthermore, the S. symbiotica symbiont associated with S. maydis appears to be strictly compartmentalized into the specialized host cells housing symbionts in aphids, the bacteriocytes, whereas the S. symbiotica symbiont associated with P. lyropictus exhibits a highly invasive phenotype, presumably because it is capable of expressing a larger set of virulence factors, including a complete flagellum for bacterial motility. Such contrasting levels of metabolic and anatomical integration for two S. symbiotica symbionts that were recently acquired as nutritional co-obligate partners reflect distinct coevolutionary processes specific to each association.

Published
2022

34. Plasticity of bacteriocytes facing nutritional stresses in the pea aphid development

Author

UCL - SST/ELI/ELIB - Biodiversity, Ribeiro Lopes, Mélanie, Gaget, Karen, Renoz, François, Duport, Gabrielle, Balmand, Séverine, Charles, Hubert, Callaerts, Patrick, Calevro, Federica, UCL - SST/ELI/ELIB - Biodiversity, Ribeiro Lopes, Mélanie, Gaget, Karen, Renoz, François, Duport, Gabrielle, Balmand, Séverine, Charles, Hubert, Callaerts, Patrick, and Calevro, Federica

Published
2022

35. Bacteriocyte plasticity in pea aphids facing amino acid stress or starvation during development

Author

UCL - SST/ELI/ELIB - Biodiversity, Ribeiro Lopes, Mélanie, Gaget, Karen, Renoz, François, Duport, Gabrielle, Balmand, Séverine, Charles, Hubert, Callaerts, Patrick, Calevro, Federica, UCL - SST/ELI/ELIB - Biodiversity, Ribeiro Lopes, Mélanie, Gaget, Karen, Renoz, François, Duport, Gabrielle, Balmand, Séverine, Charles, Hubert, Callaerts, Patrick, and Calevro, Federica

Abstract

An important contributing factor to the evolutionary success of insects is nutritional association with microbial symbionts, which provide the host insects with nutrients lacking in their unbalanced diets. These symbionts are often compartmentalized in specialized cells of the host, the bacteriocytes. Even though bacteriocytes were first described more than a century ago, few studies have explored their dynamics throughout the insect life cycle and in response to environmental stressors. Here, we use the Buchnera aphidicola/pea aphid symbiotic system to study how bacteriocytes are regulated in response to nutritional stress throughout aphid development. Using artificial diets, we analyzed the effects of depletion or excess of phenylalanine or leucine, two amino acids essential for aphid growth and whose biosynthetic pathways are shared between the host and the symbiont. Bacteriocytes responded dynamically to those treatments, while other tissues showed no obvious morphological change. Amino acid depletion resulted in an increase in bacteriocyte numbers, with the extent of the increase depending on the amino acid, while excess either caused a decrease (for leucine) or an increase (for phenylalanine). Only a limited impact on survival and fecundity was observed, suggesting that the adjustment in bacteriocyte (and symbiont) numbers is sufficient to withstand these nutritional challenges. We also studied the impact of more extreme conditions by exposing aphids to a 24 h starvation period at the beginning of nymphal development. This led to a dramatic drop in aphid survival and fecundity and a significant developmental delay. Again, bacteriocytes responded dynamically, with a considerable decrease in number and size, correlated with a decrease in the number of symbionts, which were prematurely degraded by the lysosomal system. This study shows how bacteriocyte dynamics is integrated in the physiology of insects and highlights the high plasticity of these cells

Published
2022

36. Compartmentalized into Bacteriocytes but Highly Invasive: the Puzzling Case of the Co-Obligate Symbiont Serratia symbiotica in the Aphid Periphyllus lyropictus

Author

UCL - SST/ELI/ELIB - Biodiversity, Renoz, François, Lopes, Mélanie Ribeiro, Gaget, Karen, Duport, Gabrielle, Eloy, Marie-Christine, Geelhand de Merxem, Benoît, Hance, Thierry, Calevro, Federica, UCL - SST/ELI/ELIB - Biodiversity, Renoz, François, Lopes, Mélanie Ribeiro, Gaget, Karen, Duport, Gabrielle, Eloy, Marie-Christine, Geelhand de Merxem, Benoît, Hance, Thierry, and Calevro, Federica

Abstract

Dependence on multiple nutritional symbionts that form a metabolic unit has evolved many times in insects. Although it has been postulated that host dependence on these metabolically interconnected symbionts is sustained by their high degree of anatomical integration (these symbionts are often housed in distinct symbiotic cells, the bacteriocytes, assembled into a common symbiotic organ, the bacteriome), the developmental aspects of such multipartner systems have received little attention. Aphids of the subfamilies Chaitophorinae and Lachninae typically harbor disymbiotic systems in which the metabolic capabilities of the ancient obligate symbiont Buchnera aphidicola are complemented by those of a more recently acquired nutritional symbiont, often belonging to the species Serratia symbiotica. Here, we used microscopy approaches to finely characterize the tissue tropism and infection dynamics of the disymbiotic system formed by B. aphidicola and S. symbiotica in the Norway maple aphid Periphyllus lyropictus (Chaitophorinae). Our observations show that, in this aphid, the co-obligate symbiont S. symbiotica exhibits a dual lifestyle: intracellular by being housed in large syncytial bacteriocytes embedded between B. aphidicola-containing bacteriocytes in a well-organized compartmentalization pattern, and extracellular by massively invading the digestive tract and other tissues during embryogenesis. This is the first reported case of an obligate aphid symbiont that is internalized in bacteriocytes but simultaneously adopts an extracellular lifestyle. This unusual infection pattern for an obligate insect symbiont suggests that some bacteriocyte-associated obligate symbionts, despite their integration into a cooperative partnership, still exhibit invasive behavior and escape strict compartmentalization in bacteriocytes.

Published
2022

37. Influence of bacterial symbionts on host niche and ecological diversification: an integrative approach in a whitefly model

Author

Benhamou, Sylvain, Rahioui, Isabelle, Henri, Hélène, da Silva, Pedro, Charles, Hubert, Heddi, Abdelaziz, Vavre, Fabrice, Desouhant, Emmanuel, Calevro, Federica, Mouton, Laurence, Charles, Hubert, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 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), Evolution, adaptation et comportement, Département écologie évolutive [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)-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), Génétique et évolution des interactions hôtes-parasites, and Département génétique, interactions et évolution des génomes [LBBE] (GINSENG)

Subjects
[SDV] Life Sciences [q-bio], [SDV]Life Sciences [q-bio], insect symbiosis
Abstract

International audience

Published
2022

38. High-throughput genomics and transcriptomics to decipher host-symbiont molecular dialogue in the cereal weevil Sitophilus oryzae andSodalis pierantonius endosymbiotic association

Author

Parisot, Nicolas, Ferrarini, Mariana, Goubert, Clément, Vargas-Chávez, Carlos, Vallier, Agnès, Gillet, Benjamin, Hughes, Sandrine, Baa-Puyoulet, Patrice, Charles, Hubert, Calevro, Federica, Gil, Rosario, Latorre, Amparo, Vieira, Cristina, Rebollo, R., Heddi, Abdelaziz, Charles, Hubert, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centro de Biotecnologia [Porto Alegre] (CBiot), Universidade Federal do Rio Grande do Sul [Porto Alegre] (UFRGS), 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), Equipe de recherche européenne en algorithmique et biologie formelle et expérimentale (ERABLE), 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)-Inria Lyon, Institut National de Recherche en Informatique et en Automatique (Inria), Eléments transposables, évolution, populations, Département génétique, interactions et évolution des génomes [LBBE] (GINSENG), 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), Plateforme nationale de Paléogénétique (Palgene), École normale supérieure de Lyon (ENS de Lyon), Institut de Génomique Fonctionnelle de Lyon (IGFL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Universitat de València (UV)

Subjects
[SDV] Life Sciences [q-bio], [SDV.BIBS] Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], [SDV]Life Sciences [q-bio], [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], Réseaux métaboliques réseaux génétiques
Abstract

International audience

Published
2022

39. Gene Regulatory Network Inference Using Ensembles of Predictors

Author

Peignier, Sergio, Sorin, Baptiste, Calevro, Federica, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and IEEE

Subjects
ComputingMethodologies_PATTERNRECOGNITION, Bioinformatics, Gene Regulatory Network Inference, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM], Ensemble Learning, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI]
Abstract

International audience; In the machine learning field, the technique known as ensemble learning aims at combining different base learners in order to increase the quality and the robustness of the predictions. Indeed, this approach has widely been applied to tackle, with success, real world problems from different domains, including computational biology. Nevertheless, despite the potential of this technique, ensembles that combine results from different kinds of algorithms, have been understudied in the context of gene regulatory network inference. In this paper we used a genetic algorithm and frequent itemset mining, to study and design effective ensembles, to reverse-engineer gene regulatory networks, from high-throughput data. The methods proposed here, were evaluated and compared to well-established single and ensemble methods, on real and synthetic datasets. Results demonstrate the efficiency and the robustness of these new methods, advocating for their use as gene regulatory network inference tools.

Published
2021

40. The genome of the cereal pest Sitophilus oryzae : a transposable element haven

Author

Parisot, Nicolas, Vargas-Chavez, Carlos, Goubert, Clément, Baa-Puyoulet, Patrice, Balmand, Séverine, Beranger, Louis, Blanc, Caroline, Bonnamour, Aymeric, Boulesteix, Matthieu, Burlet, Nelly, Calevro, Federica, Callaerts, Patrick, Chancy, Théo, Charles, Hubert, Colella, Stefano, Da Silva Barbosa, André, Dell’Aglio, Elisa, Di Genova, Alex, Febvay, Gérard, Gabaldon, Toni, Galvão Ferrarini, Mariana, Gerber, Alexandra, Gillet, Benjamin, Hubley, Robert, Hughes, Sandrine, Jacquin-Joly, Emmanuelle, Maire, Justin, Marcet-Houben, Marina, Masson, Florent, Meslin, Camille, Montagne, Nicolas, Moya, Andrés, Ribeiro de Vasconcelos, Ana Tereza, Richard, Gautier, Rosen, Jeb, Sagot, Marie-France, Smit, Arian F.A., Storer, Jessica, Vincent-Monegat, Carole, Vallier, Agnès, Vigneron, Aurélien, Zaidman-Remy, Anna, Zamoum, Waël, Vieira, Cristina, Rebollo, Rita, Latorre, Amparo, Heddi, Abdelaziz, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre for Genomic Regulation [Barcelona] (CRG), Universitat Pompeu Fabra [Barcelona] (UPF)-Centro Nacional de Analisis Genomico [Barcelona] (CNAG), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
[SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics, [SDV]Life Sciences [q-bio], [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], food and beverages
Abstract

Among beetles, the rice weevil Sitophilus oryzae is one of the most important pests causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions. We sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families are transcriptionally active, and changes in their expression are associated with insect endosymbiotic state. S. oryzae has undergone a high gene expansion rate, when compared to other beetles. Reconstruction of host-symbiont metabolic networks revealed that, despite its recent association with cereal weevils (30 Kyear), S. pierantonius relies on the host for several amino acids and nucleotides to survive and to produce vitamins and essential amino-acids required for insect development and cuticle biosynthesis. In addition to being an agricultural pest and a valuable endosymbiotic system, S. oryzae can be a remarkable model for studying TE evolution and regulation, along with the impact of TEs on eukaryotic genomes.

Published
2021

41. Isolation of Insect as a Platform for Transcriptomic Analyses

Author

Ribeiro Lopes, Mélanie, Simonet, Pierre, Duport, Gabrielle, Gaget, Karen, Balmand, Séverine, Sugio, Akiko, Simon, Jean-Christophe, Parisot, Nicolas, Calevro, Federica, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, 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), and ANR-16-CE02-0014,Hmicmac,Co-adaptations hôtes-microbiote: mécanismes et conséquences(2016)

Subjects
Insects, Microarrays, Aphids, food and beverages, Bacteriocytes, qRT-PCR, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, biochemical phenomena, metabolism, and nutrition, RNAseq, Transcriptomics, RNA extraction, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract

International audience; Over the past few decades, various techniques have been developed and optimized for the accurate measurement of RNA abundance in cells or tissues. These methods have been instrumental in gaining insight in complex systems such as host-symbiont associations. The pea aphid model has recently emerged as a powerful and experimentally tractable system for studying symbiotic relationships and it is the subject of a growing number of molecular studies. Nevertheless, the lack of standardized protocols for the collection of bacteriocytes, the specialized host cells harboring the symbionts, has limited its use. This chapter provides a simple, step-by-step dissection protocol for the rapid isolation of aphid bacteriocytes. We then describe an adapted protocol for efficient extraction and purification of bacteriocyte RNA that can be used for most downstream transcriptomic analyses.

Published
2021
Full Text
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44. The aphid BCR4 structure and activity uncover a new defensin peptide superfamily

Author

Loth, Karine, primary, Parisot, Nicolas, additional, Paquet, Francoise, additional, Sivignon, Catherine, additional, Rahioui, Isabelle, additional, Lopes, Melanie Ribeiro, additional, Gaget, Karen, additional, Duport, Gabrielle, additional, Delmas, Agnes F, additional, Aucagne, Vincent, additional, Heddi, Abdelaziz, additional, Calevro, Federica, additional, and da Silva, Pedro, additional

Published
2021
Full Text
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47. Influence of secondary symbionts on host plant utilization and selection in the whitefly Bemisia tabaci

Author

Benhamou, Sylvain, Rahioui, Isabelle, Henri, Hélène, Belgaidi, Zainab, Charles, Hubert, da Silva, Pedro, Heddi, Abdelaziz, Vavre, Fabrice, Desouhant, Emmanuel, Calevro, Federica, Mouton, Laurence, Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 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), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), An algorithmic view on genomes, cells, and environments (BAMBOO), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-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)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-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), Génétique et évolution des interactions hôtes-parasites, Département génétique, interactions et évolution des génomes [LBBE] (GINSENG), 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), Evolution, adaptation et comportement, Département écologie évolutive [LBBE], and Charles, Hubert

Subjects
[SDE] Environmental Sciences, [SDV] Life Sciences [q-bio], secondary symbionts, [SDV]Life Sciences [q-bio], [SDE]Environmental Sciences, insect symbiosis, metabolism
Abstract

International audience

Published
2021

48. Bacteriocyte plasticity in pea aphids facing amino acid stress or starvation during development.

Author

Lopes, Mélanie Ribeiro, Gaget, Karen, Renoz, François, Duport, Gabrielle, Balmand, Séverine, Charles, Hubert, Callaerts, Patrick, and Calevro, Federica

Subjects
PEA aphid, AMINO acids, INSECT physiology, ESSENTIAL amino acids, LIFE cycles (Biology)
Abstract

An important contributing factor to the evolutionary success of insects is nutritional association with microbial symbionts, which provide the host insects with nutrients lacking in their unbalanced diets. These symbionts are often compartmentalized in specialized cells of the host, the bacteriocytes. Even though bacteriocytes were first described more than a century ago, few studies have explored their dynamics throughout the insect life cycle and in response to environmental stressors. Here, we use the Buchnera aphidicola/ pea aphid symbiotic system to study how bacteriocytes are regulated in response to nutritional stress throughout aphid development. Using artificial diets, we analyzed the effects of depletion or excess of phenylalanine or leucine, two amino acids essential for aphid growth and whose biosynthetic pathways are shared between the host and the symbiont. Bacteriocytes responded dynamically to those treatments, while other tissues showed no obvious morphological change. Amino acid depletion resulted in an increase in bacteriocyte numbers, with the extent of the increase depending on the amino acid, while excess either caused a decrease (for leucine) or an increase (for phenylalanine). Only a limited impact on survival and fecundity was observed, suggesting that the adjustment in bacteriocyte (and symbiont) numbers is sufficient to withstand these nutritional challenges. We also studied the impact of more extreme conditions by exposing aphids to a 24 h starvation period at the beginning of nymphal development. This led to a dramatic drop in aphid survival and fecundity and a significant developmental delay. Again, bacteriocytes responded dynamically, with a considerable decrease in number and size, correlated with a decrease in the number of symbionts, which were prematurely degraded by the lysosomal system. This study shows how bacteriocyte dynamics is integrated in the physiology of insects and highlights the high plasticity of these cells. [ABSTRACT FROM AUTHOR]

Published
2022
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