37 results on '"Cadoret JP"'
Search Results
2. Development and optimization of a metabolite extraction process for the high throughput screening of microalgal chimiodiversity
- Author
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Serive, B, primary, Kaas, R, additional, Bérard, JB, additional, Kornprobst, JM, additional, Deslandes, E, additional, Fauchon, M, additional, Picot, L, additional, and Cadoret, JP, additional
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- 2012
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Catalog
3. Monospecific renaming within the cyanobacterial genus Limnospira (Spirulina) and consequences for food authorization.
- Author
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Roussel T, Halary S, Duval C, Piquet B, Cadoret JP, Vernès L, Bernard C, and Marie B
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- Phylogeny, Spirulina classification, Genetic Variation
- Abstract
Aims: The cyanobacterial genus, Limnospira (anc. Arthrospira Stizenberger ex Gomont 1892), commonly called "Spirulina", is widely used for commercial purposes because of its high protein content and beneficial probiotic metabolites. Thus, the taxonomy of this genus is important because of its consequences for food applications., Methods and Results: We constructed a database with formation on all Limnospira strains plus new ones from 72 new French isolates. We used a polyphasic approach (phylogenetic, phylogenomic, presence or absence of coding DNA sequences, morphological, and ultrastructure analyses) to confirm that the species A. platensis belonged to the genus Limnospira (L. platensis Gomont comb. nov. Basionym. Arthrospira platensis Gomont 1892) and that the genus Limnospira was monospecific, only represented by L. platensis., Conclusions: This study highlighted the large intra-specific diversity of L. platensis, independent of the affiliations of the phylogenetic clades or geographical location of the habitats and the subsequent physiological and metabolic plasticity., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.) more...
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- 2023
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4. Correction to: Docking and in silico toxicity assessment of Arthrospira compounds as potential antiviral agents against SARS-CoV-2.
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Petit L, Vernès L, and Cadoret JP
- Abstract
[This corrects the article DOI: 10.1007/s10811-021-02372-9.]., (© Springer Nature B.V. 2021.)
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- 2021
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5. Docking and in silico toxicity assessment of Arthrospira compounds as potential antiviral agents against SARS-CoV-2.
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Petit L, Vernès L, and Cadoret JP
- Abstract
A race is currently being launched as a result of the international health situation. This race aims to find, by various means, weapons to counter the Covid-19 pandemic now widespread on all continents. The aquatic world and in particular that of photosynthetic organisms is regularly highlighted but paradoxically little exploited in view of the tremendous possibilities it offers. Computational tools allow not only to clear the existence and activity of many molecules but also to model their relationships with receptors identified in potential hosts. On a routine basis, our laboratory carries out a research activity on functionalities of molecules derived from algae using in silico tools. We have implemented our skills in algae biology and in modeling, as tests in order to identify molecules expressed by the genus Arthrospira showing an antiviral potential and more particularly anti-SARS-CoV-2. Using consensus docking and redocking with Autodock Vina and SwissDock, we were able to identify several promising molecules from Arthrospira : phycocyanobilin, phycoerythrobilin, phycourobilin, and folic acid. These four compounds showed reliable binding energies comprised between - 6.95 and - 7.45 kcal.mol
-1 in Autodock Vina and between - 9.285 and - 10.35 kcal.mol-1 with SwissDock. Toxicity prediction as well as current regulations provided promising arguments for the inclusion of these compounds in further studies to assess their ability to compete with the SARS-CoV-2/ACE2 complex both in vitro and in vivo ., Supplementary Information: The online version contains supplementary material available at 10.1007/s10811-021-02372-9., (© The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature 2021, corrected publication 2021.) more...- Published
- 2021
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6. Chloroplast Dual Divergent Promoter Plasmid for Heterologous Protein Expression in Tetraselmis suecica (Chlorophyceae, Chlorodendrales).
- Author
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Gutiérrez CL, Muñoz C, San Martín M, Cadoret JP, and Henríquez V
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- Chloroplasts, Plasmids, Promoter Regions, Genetic, Ribulose-Bisphosphate Carboxylase genetics, Chlorophyceae
- Abstract
The eukaryotic green microalga Tetraselmis suecica is commonly used for aquaculture purposes because of its high stress tolerance and ease of culture in a wide spectrum of environments; they are therefore suitable candidates for biotechnology applications. To date, no data are available regarding chloroplast transformation vectors based on specific endogenous promoters and homologous targeting regions. We report on the identification of Tetraselmis suecica genes encoding the ribulose bisphosphate carboxylase/oxygenase large subunit protein, the photosystem II D1 protein and the ATP synthase CF1-beta subunit protein together with their untranslated regions (5'UTR, 3'UTR). The full-length ORFs of the putative genes with their regulatory sequences were obtained. We were also able to identify the downstream 3' end of the large subunit ribosomal RNA gene (23S) along with the 5S RNA end-to-end with the psbA gene on the complementary strand. The intergenic region between these genes appears to be a good target site for the integration of target proteins. Moreover, we identified a back-to-back promoter region among the rbcL and atpB genes. To assess the bidirectionality activities of both promoters, a dual reporter vector was constructed for Tetraselmis suecica transformation containing the cat and TurboGFP genes driven by the 5'rbcL/5'atpB divergent promoter. The vector included the 23S-5S and psbA nucleotide sequences as flanking regions. These flanking regions provided suitable insertion sites within the chloroplast genome for cassette integration via homologous recombination. Simultaneous expression of the chloramphenicol-resistant conferring gene and the gene coding for TurboGFP driven by 5'rbcL/5'atpB showed a potent natural bidirectional promoter as a reliable genetic tool., (© 2020 Phycological Society of America.) more...
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- 2020
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7. What Is in Store for EPS Microalgae in the Next Decade?
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Pierre G, Delattre C, Dubessay P, Jubeau S, Vialleix C, Cadoret JP, Probert I, and Michaud P
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- Biofuels, Biomass, Culture Media, Humans, Seaweed chemistry, Bioengineering, Microalgae chemistry, Polysaccharides chemistry
- Abstract
Microalgae and their metabolites have been an El Dorado since the turn of the 21st century. Many scientific works and industrial exploitations have thus been set up. These developments have often highlighted the need to intensify the processes for biomass production in photo-autotrophy and exploit all the microalgae value including ExoPolySaccharides (EPS). Indeed, the bottlenecks limiting the development of low value products from microalgae are not only linked to biology but also to biological engineering problems including harvesting, recycling of culture media, photoproduction, and biorefinery. Even respecting the so-called "Biorefinery Concept", few applications had a chance to emerge and survive on the market. Thus, exploiting EPS from microalgae for industrial applications in some low-value markets such as food is probably not a mature proposition considering the competitiveness of polysaccharides from terrestrial plants, macroalgae, and bacteria. However, it does not imply drawing a line on their uses but rather "thinking them" differently. This review provides insights into microalgae, EPS, and their exploitation. Perspectives on issues affecting the future of EPS microalgae are also addressed with a critical point of view. more...
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- 2019
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8. Marine algae as attractive source to skin care.
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Berthon JY, Nachat-Kappes R, Bey M, Cadoret JP, Renimel I, and Filaire E
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- Collagen genetics, Collagen metabolism, Gene Expression Regulation, Humans, Matrix Metalloproteinases genetics, Matrix Metalloproteinases metabolism, Polyphenols chemistry, Polyphenols isolation & purification, Polyphenols pharmacology, Polysaccharides chemistry, Polysaccharides isolation & purification, Polysaccharides pharmacology, Protective Agents chemistry, Protective Agents pharmacology, Reactive Oxygen Species metabolism, Signal Transduction, Skin pathology, Skin radiation effects, Skin Aging drug effects, Skin Aging radiation effects, Skin Care methods, Tissue Inhibitor of Metalloproteinases genetics, Tissue Inhibitor of Metalloproteinases metabolism, Ultraviolet Rays adverse effects, Chlorophyta chemistry, Phaeophyceae chemistry, Protective Agents isolation & purification, Reactive Oxygen Species antagonists & inhibitors, Rhodophyta chemistry, Skin drug effects
- Abstract
As the largest organ in the human body, the skin has multiple functions of which one of the most important is the protection against various harmful stressors. The keratinised stratified epidermis and an underlying thick layer of collagen-rich dermal connective tissues are important components of the skin. The environmental stressors such as ultraviolet radiation (UVR) and pollution increase the levels of reactive oxygen species (ROS), contributing to clinical manifestations such as wrinkle formation and skin aging. Skin aging is related to the reduction of collagen production and decrease of several enzymatic activities including matrix metalloproteinases (MMPs), which degrade collagen structure in the dermis; and tissue inhibitor of metalloproteinases (TIMPs), which inhibit the action of MMPs. In addition to alterations of DNA, signal transduction pathways, immunology, UVR, and pollution activate cell surface receptors of keratinocytes and fibroblasts in the skin. This action leads to a breakdown of collagen in the extracellular matrix and a shutdown of new collagen synthesis. Therefore, an efficient antioxidants strategy is of major importance in dermis and epidermis layers. Marine resources have been recognised for their biologically active substances. Among these, marine algae are rich-sources of metabolites, which can be used to fight against oxidative stress and hence skin aging. These metabolites include, among others, mycosporine-like amino acids (MAAs), polysaccharides, sulphated polysaccharides, glucosyl glycerols, pigments, and polyphenols. This paper reviews the role of oxidative processes in skin damage and the action of the compounds from algae on the physiological processes to maintain skin health. more...
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- 2017
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9. Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups.
- Author
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Serive B, Nicolau E, Bérard JB, Kaas R, Pasquet V, Picot L, and Cadoret JP
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- Carotenoids isolation & purification, Chromatography, High Pressure Liquid, Fresh Water analysis, Microalgae classification, Pigments, Biological isolation & purification, Porphyrins isolation & purification, Seawater analysis, Xanthines analysis, Xanthines isolation & purification, Carotenoids analysis, Microalgae chemistry, Pigments, Biological analysis, Porphyrins analysis
- Abstract
Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature. Using an optimized extraction process coupled to a HPLC de-replication strategy, we examined the pigment composition of 37 microalgae strains, representative of the broad taxonomic diversity of marine and freshwater species (excluding cyanobacteria). For each species, the major pigments already described were unambiguously identified. We also observed the presence of several minor unidentified pigments in each chromatogram. The global analysis of pigment compositions revealed a total of 124 pigments, including 98 pigments or derivatives unidentified using the standards. Absorption spectra indicated that 35 corresponded to chlorophyll/porphyrin derivatives, 57 to carotenoids and six to derivatives having both spectral signatures. Sixty-one of these unidentified or new carotenoids and porphyrin derivatives were characteristic of particular strains or species, indicating their possible use as highly specific chemotaxonomic markers capable of identifying one strain out of the 37 selected. We developed a graphical analysis using Gephi software to give a clear representation of pigment communities among the various phytoplankton strains, and to reveal strain-characteristic and shared pigments. This made it possible to reconstruct the taxonomic evolution of microalgae classes, on the basis of the conservation, loss, and/or appearance of pigments. more...
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- 2017
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10. Transcription factors in microalgae: genome-wide prediction and comparative analysis.
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Thiriet-Rupert S, Carrier G, Chénais B, Trottier C, Bougaran G, Cadoret JP, Schoefs B, and Saint-Jean B
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- Chlamydomonas reinhardtii genetics, Cyanobacteria genetics, Haptophyta genetics, Porphyridium genetics, Proteome, Stramenopiles genetics, Biological Evolution, Microalgae genetics, Multigene Family, Transcription Factors genetics
- Abstract
Background: Studying transcription factors, which are some of the key players in gene expression, is of outstanding interest for the investigation of the evolutionary history of organisms through lineage-specific features. In this study we performed the first genome-wide TF identification and comparison between haptophytes and other algal lineages., Results: For TF identification and classification, we created a comprehensive pipeline using a combination of BLAST, HMMER and InterProScan software. The accuracy evaluation of the pipeline shows its applicability for every alga, plant and cyanobacterium, with very good PPV and sensitivity. This pipeline allowed us to identify and classified the transcription factor complement of the three haptophytes Tisochrysis lutea, Emiliania huxleyi and Pavlova sp.; the two stramenopiles Phaeodactylum tricornutum and Nannochloropsis gaditana; the chlorophyte Chlamydomonas reinhardtii and the rhodophyte Porphyridium purpureum. By using T. lutea and Porphyridium purpureum, this work extends the variety of species included in such comparative studies, allowing the detection and detailed study of lineage-specific features, such as the presence of TF families specific to the green lineage in Porphyridium purpureum, haptophytes and stramenopiles. Our comprehensive pipeline also allowed us to identify fungal and cyanobacterial TF families in the algal nuclear genomes., Conclusions: This study provides examples illustrating the complex evolutionary history of algae, some of which support the involvement of a green alga in haptophyte and stramenopile evolution. more...
- Published
- 2016
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11. High-affinity nitrate/nitrite transporter genes (Nrt2) in Tisochrysis lutea: identification and expression analyses reveal some interesting specificities of Haptophyta microalgae.
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Charrier A, Bérard JB, Bougaran G, Carrier G, Lukomska E, Schreiber N, Fournier F, Charrier AF, Rouxel C, Garnier M, Cadoret JP, and Saint-Jean B
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- Amino Acid Sequence, Anion Transport Proteins chemistry, Anion Transport Proteins metabolism, Exons, Introns, Molecular Sequence Data, RNA, Messenger genetics, Sequence Homology, Amino Acid, Transcription, Genetic, Anion Transport Proteins genetics, Genes, Plant, Microalgae genetics, Nitrates metabolism, Nitrites metabolism
- Abstract
Microalgae have a diversity of industrial applications such as feed, food ingredients, depuration processes and energy. However, microalgal production costs could be substantially improved by controlling nutrient intake. Accordingly, a better understanding of microalgal nitrogen metabolism is essential. Using in silico analysis from transcriptomic data concerning the microalgae Tisochrysis lutea, four genes encoding putative high-affinity nitrate/nitrite transporters (TlNrt2) were identified. Unlike most of the land plants and microalgae, cloning of genomic sequences and their alignment with complementary DNA (cDNA) sequences did not reveal the presence of introns in all TlNrt2 genes. The deduced TlNRT2 protein sequences showed similarities to NRT2 proteins of other phyla such as land plants and green algae. However, some interesting specificities only known among Haptophyta were also revealed, especially an additional sequence of 100 amino acids forming an atypical extracellular loop located between transmembrane domains 9 and 10 and the function of which remains to be elucidated. Analyses of individual TlNrt2 gene expression with different nitrogen sources and concentrations were performed. TlNrt2.1 and TlNrt2.3 were strongly induced by low NO3 (-) concentration and repressed by NH4 (+) substrate and were classified as inducible genes. TlNrt2.2 was characterized by a constitutive pattern whatever the substrate. Finally, TlNrt2.4 displayed an atypical response that was not reported earlier in literature. Interestingly, expression of TlNrt2.4 was rather related to internal nitrogen quota level than external nitrogen concentration. This first study on nitrogen metabolism of T. lutea opens avenues for future investigations on the function of these genes and their implication for industrial applications., (© 2015 Scandinavian Plant Physiology Society.) more...
- Published
- 2015
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12. UPLC-MSE profiling of Phytoplankton metabolites: application to the identification of pigments and structural analysis of metabolites in Porphyridium purpureum.
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Juin C, Bonnet A, Nicolau E, Bérard JB, Devillers R, Thiéry V, Cadoret JP, and Picot L
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- Biomarkers metabolism, Chromatography, High Pressure Liquid, Cyclopropanes chemistry, Cyclopropanes isolation & purification, Cyclopropanes metabolism, Databases, Chemical, Drug Discovery methods, Galactolipids biosynthesis, Galactolipids chemistry, Galactolipids isolation & purification, Hydroxylation, Metabolomics methods, Microalgae growth & development, Microalgae isolation & purification, Microalgae metabolism, Molecular Structure, Molecular Weight, Photobioreactors, Phytoplankton growth & development, Phytoplankton isolation & purification, Pigments, Biological chemistry, Pigments, Biological isolation & purification, Plant Extracts chemistry, Plastoquinone chemistry, Plastoquinone isolation & purification, Plastoquinone metabolism, Porphyridium growth & development, Porphyridium isolation & purification, Software, Spectrometry, Mass, Electrospray Ionization, Tandem Mass Spectrometry, Phytoplankton metabolism, Pigments, Biological biosynthesis, Porphyridium metabolism
- Abstract
A fast and high-resolution UPLC-MSE analysis was used to identify phytoplankton pigments in an ethanol extract of Porphyridium purpureum (Pp) devoid of phycobiliproteins. In a first step, 22 standard pigments were analyzed by UPLC-MSE to build a database including retention time and accurate masses of parent and fragment ions. Using this database, seven pigments or derivatives previously reported in Pp were unequivocally identified: β,β-carotene, chlorophyll a, zeaxanthin, chlorophyllide a, pheophorbide a, pheophytin a, and cryptoxanthin. Minor amounts of Divinyl chlorophyll a, a chemotaxonomic pigment marker for prochlorophytes, were also unequivocally identified using the database. Additional analysis of ionization and fragmentation patterns indicated the presence of ions that could correspond to hydroxylated derivatives of chlorophyll a and pheophytin a, produced during the ethanolic extraction, as well as previously described galactosyldiacylglycerols, the thylakoid coenzyme plastoquinone, and gracilamide B, a molecule previously reported in the red seaweed Gracillaria asiatica. These data point to UPLC-MSE as an efficient technique to identify phytoplankton pigments for which standards are available, and demonstrate its major interest as a complementary method for the structural elucidation of ionizable marine molecules. more...
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- 2015
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13. The use of fluorescent Nile red and BODIPY for lipid measurement in microalgae.
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Rumin J, Bonnefond H, Saint-Jean B, Rouxel C, Sciandra A, Bernard O, Cadoret JP, and Bougaran G
- Abstract
Microalgae are currently emerging as one of the most promising alternative sources for the next generation of food, feed, cosmetics and renewable energy in the form of biofuel. Microalgae constitute a diverse group of microorganisms with advantages like fast and efficient growth. In addition, they do not compete for arable land and offer very high lipid yield potential. Major challenges for the development of this resource are to select lipid-rich strains using high-throughput staining for neutral lipid content in microalgae species. For this purpose, the fluorescent dyes most commonly used to quantify lipids are Nile red and BODIPY 505/515. Their fluorescent staining for lipids offers a rapid and inexpensive analysis tool to measure neutral lipid content, avoiding time-consuming and costly gravimetric analysis. This review collates and presents recent advances in algal lipid staining and focuses on Nile red and BODIPY 505/515 staining characteristics. The available literature addresses the limitations of fluorescent dyes under certain conditions, such as spectral properties, dye concentrations, cell concentrations, temperature and incubation duration. Moreover, the overall conclusion of the present review study gives limitations on the use of fluorochrome for screening of lipid-rich microalgae species and suggests improved protocols for staining recalcitrant microalgae and recommendations for the staining quantification. more...
- Published
- 2015
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14. Microwave-assisted extraction of phycobiliproteins from Porphyridium purpureum.
- Author
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Juin C, Chérouvrier JR, Thiéry V, Gagez AL, Bérard JB, Joguet N, Kaas R, Cadoret JP, and Picot L
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- Chromatography, High Pressure Liquid, Microwaves, Phycobiliproteins chemistry, Phycocyanin chemistry, Phycoerythrin chemistry, Porphyridium chemistry, Phycobiliproteins isolation & purification, Phycocyanin isolation & purification, Phycoerythrin isolation & purification
- Abstract
In the present study, microwave-assisted extraction was first employed to extract the phycobiliproteins of Porphyridium purpureum (Pp). Freeze-dried Pp cells were subjected to microwave-assisted extraction (MAE) to extract phycoerythin (PE), phycocyanin (PC), and allophycocyanin (APC). MAE combined reproducibility and high extraction yields and allowed a 180- to 1,080-fold reduction of the extraction time compared to a conventional soaking process. The maximal PE extraction yield was obtained after 10-s MAE at 40 °C, and PE was thermally damaged at temperatures higher than 40 °C. In contrast, a flash irradiation for 10 s at 100 °C was the best process to efficiently extract PC and APC, as it combined a high temperature necessary to extract them from the thylakoid membrane to a short exposure to thermal denaturation. The extraction order of the three phycobiliproteins was coherent with the structure of Pp phycobilisomes. Moreover, the absorption and fluorescence properties of MAE extracted phycobiliproteins were stable for several months after the microwave treatment. Scanning electron microscopy indicated that MAE at 100 °C induced major changes in the Pp cell morphology, including fusion of the exopolysaccharidic cell walls and cytoplasmic membranes of adjacent cells. As a conclusion, MAE is a fast and high yield process efficient to extract and pre-purify phycobiliproteins, even from microalgae containing a thick exopolysaccharidic cell wall. more...
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- 2015
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15. Comparative proteomics reveals proteins impacted by nitrogen deprivation in wild-type and high lipid-accumulating mutant strains of Tisochrysis lutea.
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Garnier M, Carrier G, Rogniaux H, Nicolau E, Bougaran G, Saint-Jean B, and Cadoret JP
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- Haptophyta genetics, Lipids genetics, Microalgae genetics, Proteome genetics, Species Specificity, Haptophyta metabolism, Lipid Metabolism physiology, Microalgae metabolism, Mutation, Nitrogen metabolism, Proteome metabolism, Proteomics methods
- Abstract
Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for biomass feedstock, food and biofuel production. Using a domesticated oleaginous algae Tisochrysis lutea, we performed the first comparative proteomic analysis on the wild type strain and a selected lipid over-accumulating mutant. 2-DE analysis was made on these strains cultured in two metabolic conditions, with and without nitrogen deprivation, which revealed significant differences in proteomes according to both strain and nitrogen availability. Mass spectrometry allowed us to identify 37 proteins that were differentially expressed between the two strains, and 17 proteins regulated by nitrogen starvation concomitantly with lipid accumulation. The proteins identified are known to be involved in various metabolic pathways including lipid, carbohydrate, amino acid, energy and pigment metabolisms, photosynthesis, protein translation, stress response and cell division. Four candidates were selected for possible implication in the over-accumulation of lipids during nitrogen starvation. These include the plastid beta-ketoacyl-ACP reductase protein, the coccolith scale associated protein and two glycoside hydrolases involved in biosynthesis of fatty acids, carbon homeostasis and carbohydrate catabolism, respectively. This proteomic study confirms the impact of nitrogen starvation on overall metabolism and provides new perspectives to study the lipid over-accumulation in the prymnesiophyte haptophyte T. lutea., Biological Significance: This paper study consists of the first proteomic analysis on Tisochrysis lutea, a non-model marine microalga of interest for aquaculture and lipids production. Comparative proteomics revealed proteins putatively involved in the up-accumulation of neutral lipids in a mutant strain during nitrogen starvation. The results are of great importance for future works to improve lipid accumulation in microalgae of biotechnological interest for biofuel production. This article is part of a Special Issue entitled: Proteomics of non-model organisms., (Copyright © 2014 Elsevier B.V. All rights reserved.) more...
- Published
- 2014
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16. Comparative transcriptome of wild type and selected strains of the microalgae Tisochrysis lutea provides insights into the genetic basis, lipid metabolism and the life cycle.
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Carrier G, Garnier M, Le Cunff L, Bougaran G, Probert I, De Vargas C, Corre E, Cadoret JP, and Saint-Jean B
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- Algal Proteins metabolism, Gene Expression Profiling, Genetic Variation, Genotype, High-Throughput Nucleotide Sequencing, Microalgae growth & development, Microalgae metabolism, Molecular Sequence Annotation, Polymorphism, Single Nucleotide, Recombination, Genetic, Selection, Genetic, Sequence Analysis, DNA, Algal Proteins genetics, Life Cycle Stages genetics, Lipid Metabolism genetics, Microalgae genetics, Transcriptome
- Abstract
The applied exploitation of microalgae cultures has to date almost exclusively involved the use of wild type strains, deposited over decades in dedicated culture collections. Concomitantly, the concept of improving algae with selection programs for particular specific purposes is slowly emerging. Studying since a decade an economically and ecologically important haptophyte Tisochrysis lutea (Tiso), we took advantage of the availability of wild type (Tiso-Wt) and selected (Tiso-S2M2) strains to conduct a molecular variations study. This endeavour presented substantial challenges: the genome assembly was not yet available, the life cycle unknown and genetic diversity of Tiso-Wt poorly documented. This study brings the first molecular data in order to set up a selection strategy for that microalgae. Following high-throughput Illumina sequencing, transcriptomes of Tiso-Wt and Tiso-S2M2 were de novo assembled and annotated. Genetic diversity between both strains was analyzed and revealed a clear conservation, while a comparison of transcriptomes allowed identification of polymorphisms resulting from the selection program. Of 34,374 transcripts, 291 were differentially expressed and 165 contained positional polymorphisms (SNP, Indel). We focused on lipid over-accumulation of the Tiso-S2M2 strain and 8 candidate genes were identified by combining analysis of positional polymorphism, differential expression levels, selection signature and by study of putative gene function. Moreover, genetic analysis also suggests the existence of a sexual cycle and genetic recombination in Tisochrysis lutea. more...
- Published
- 2014
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17. Antiproliferative activity of Cyanophora paradoxa pigments in melanoma, breast and lung cancer cells.
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Baudelet PH, Gagez AL, Bérard JB, Juin C, Bridiau N, Kaas R, Thiéry V, Cadoret JP, and Picot L
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- Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Apoptosis drug effects, Cell Line, Tumor, Cryptoxanthins, Cyanophora metabolism, Female, Humans, MCF-7 Cells, Pigments, Biological chemistry, Skin Neoplasms, Xanthophylls chemistry, Xanthophylls pharmacology, Zeaxanthins, Melanoma, Cutaneous Malignant, Breast Neoplasms drug therapy, Cell Proliferation drug effects, Cyanophora chemistry, Lung Neoplasms drug therapy, Melanoma drug therapy, Pigments, Biological pharmacology
- Abstract
The glaucophyte Cyanophora paradoxa (Cp) was chemically investigated to identify pigments efficiently inhibiting malignant melanoma, mammary carcinoma and lung adenocarcinoma cells growth. Cp water and ethanol extracts significantly inhibited the growth of the three cancer cell lines in vitro, at 100 µg · mL(-1). Flash chromatography of the Cp ethanol extract, devoid of c-phycocyanin and allophycocyanin, enabled the collection of eight fractions, four of which strongly inhibited cancer cells growth at 100 µg · mL(-1). Particularly, two fractions inhibited more than 90% of the melanoma cells growth, one inducing apoptosis in the three cancer cells lines. The detailed analysis of Cp pigment composition resulted in the discrimination of 17 molecules, ten of which were unequivocally identified by high resolution mass spectrometry. Pheophorbide a, β-cryptoxanthin and zeaxanthin were the three main pigments or derivatives responsible for the strong cytotoxicity of Cp fractions in cancer cells. These data point to Cyanophora paradoxa as a new microalgal source to purify potent anticancer pigments, and demonstrate for the first time the strong antiproliferative activity of zeaxanthin and β-cryptoxanthin in melanoma cells. more...
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- 2013
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18. The potential of microalgae for the production of bioactive molecules of pharmaceutical interest.
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Mimouni V, Ulmann L, Pasquet V, Mathieu M, Picot L, Bougaran G, Cadoret JP, Morant-Manceau A, and Schoefs B
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- Animals, Biological Products metabolism, Diatoms metabolism, Humans, Lipids biosynthesis, Pigments, Biological biosynthesis, Microalgae metabolism
- Abstract
Through the photosynthetic activity, microalgae process more than 25% of annual inorganic carbon dissolved in oceans into carbohydrates that ultimately, serve to feed the other levels of the trophic networks. Besides, microalgae synthesize bioactive molecules such as pigments and lipids that exhibit health properties. In addition, abiotic stresses, such as high irradiance, nutrient starvation, UV irradiation, trigger metabolic reorientations ending with the production of other bioactive compounds such as ω-3 fatty acids or carotenoids. Traditionally, these compounds are acquired through the dietary alimentation. The increasing, and often unsatisfied, demand for compounds from natural sources, combined with the decrease of the halieutic resources, forces the search for alternative resources for these bioactive components. Microalgae possess this strong potential. For instance, the diatom Odontella aurita is already commercialized as dietary complement and compete with fish oil for human nutrition. In this contribution, the microalga world is briefly presented. Then, the different types of biologically active molecules identified in microalgae are presented together with their potential use. Due to space limitation, only the biological activities of lipids and pigments are described in details. The contribution ends with a description of the possibilities to play with the environmental constrains to increase the productivity of biologically active molecules by microalgae and by a description of the progresses made in the field of alga culturing. more...
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- 2012
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19. Selection and optimisation of a method for efficient metabolites extraction from microalgae.
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Serive B, Kaas R, Bérard JB, Pasquet V, Picot L, and Cadoret JP
- Subjects
- Biofuels, Carbon Dioxide isolation & purification, Microalgae metabolism
- Abstract
Over the last decade, the use of microalgae for biofuel production and carbon dioxide sequestration has become a challenge worldwide. Processing costs are still too high for these methods to be profitable though, leading to a need to find high value by-products to optimise the added value of this biomass. For high-throughput screening of such metabolites, it is essential to reach the inner content of the cell. This paper presents research and development of a technique enabling a high extraction yield of any metabolite, taking into account the difficulty of extracting bound and or inaccessible molecules with a wide variety of polarities. To this end, several disruption techniques were tested at laboratory scale on two biological models: Porphyridium purpureum and Phaeodactylum tricornutum. A mixer mill gave the best results, offering access to a broad diversity of metabolites from microalgae for high-throughput screening., (Copyright © 2012 Elsevier Ltd. All rights reserved.) more...
- Published
- 2012
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20. Enhancement of neutral lipid productivity in the microalga Isochrysis affinis Galbana (T-Iso) by a mutation-selection procedure.
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Bougaran G, Rouxel C, Dubois N, Kaas R, Grouas S, Lukomska E, Le Coz JR, and Cadoret JP
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- Fatty Acids analysis, Flow Cytometry, Fluorometry, Haptophyta chemistry, Haptophyta radiation effects, Ultraviolet Rays, Haptophyta genetics, Haptophyta metabolism, Lipid Metabolism, Metabolic Engineering, Mutation, Selection, Genetic
- Abstract
Microalgae offer a high potential for energetic lipid storage as well as high growth rates. They are therefore considered promising candidates for biofuel production, with the selection of high lipid-producing strains a major objective in projects on the development of this technology. We developed a mutation-selection method aimed at increasing microalgae neutral lipid productivity. A two step method, based on UVc irradiation followed by flow cytometry selection, was applied to a set of strains that had an initial high lipid content and improvement was assessed by means of Nile-red fluorescence measurements. The method was first tested on Isochrysis affinis galbana (T-Iso). Following a first round of mutation-selection, the total fatty acid content had not increased significantly, being 262 ± 21 mgTFA (gC)-1 for the wild type (WT) and 269 ± 49 mgTFA (gC)-1 for the selected population (S1M1). Conversely, fatty acid distribution among the lipid classes was affected by the process, resulting in a 20% increase for the fatty acids in the neutral lipids and a 40% decrease in the phospholipids. After a second mutation-selection step (S2M2), the total fatty acid content reached 409 ± 64 mgTFA (gC)-1 with a fatty acid distribution similar to the S1M1 population. Growth rate remained unaffected by the process, resulting in a 80% increase for neutral lipid productivity., (Copyright © 2012 Wiley Periodicals, Inc.) more...
- Published
- 2012
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21. Integrative taxonomy of the Pavlovophyceae (Haptophyta): a reassessment.
- Author
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Bendif el M, Probert I, Hervé A, Billard C, Goux D, Lelong C, Cadoret JP, and Véron B
- Subjects
- Evolution, Molecular, Haptophyta genetics, Haptophyta isolation & purification, Haptophyta ultrastructure, Molecular Sequence Data, Haptophyta classification, Phylogeny
- Abstract
The Pavlovophyceae (Haptophyta) contains four genera (Pavlova, Diacronema, Exanthemachrysis and Rebecca) and only thirteen characterised species, several of which are important in ecological and economic contexts. We have constructed molecular phylogenies inferred from sequencing of ribosomal gene markers with comprehensive coverage of the described diversity, using type strains when available, together with additional cultured strains. The morphology and ultrastructure of 12 of the described species was also re-examined and the pigment signatures of many culture strains were determined. The molecular analysis revealed that sequences of all described species differed, although those of Pavlova gyrans and P. pinguis were nearly identical, these potentially forming a single cryptic species complex. Four well-delineated genetic clades were identified, one of which included species of both Pavlova and Diacronema. Unique combinations of morphological/ultrastructural characters were identified for each of these clades. The ancestral pigment signature of the Pavlovophyceae consisted of a basic set of pigments plus MV chl cPAV, the latter being entirely absent in the Pavlova + Diacronema clade and supplemented by DV chl cPAV in part of the Exanthemachrysis clade. Based on this combination of characters, we propose a taxonomic revision of the class, with transfer of several Pavlova species to an emended Diacronema genus. The evolution of the class is discussed in the context of the phylogenetic reconstruction presented., (Copyright © 2011 Elsevier GmbH. All rights reserved.) more...
- Published
- 2011
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22. N-glycans of Phaeodactylum tricornutum diatom and functional characterization of its N-acetylglucosaminyltransferase I enzyme.
- Author
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Baïet B, Burel C, Saint-Jean B, Louvet R, Menu-Bouaouiche L, Kiefer-Meyer MC, Mathieu-Rivet E, Lefebvre T, Castel H, Carlier A, Cadoret JP, Lerouge P, and Bardor M
- Subjects
- Amino Acid Sequence, Animals, CHO Cells, Computational Biology methods, Cricetinae, Cricetulus, Diatoms genetics, Endoplasmic Reticulum genetics, Genetic Complementation Test methods, Genome-Wide Association Study methods, Golgi Apparatus enzymology, Golgi Apparatus genetics, Humans, Mice, Molecular Sequence Data, Mutation, N-Acetylglucosaminyltransferases genetics, Polysaccharides genetics, Receptors, G-Protein-Coupled genetics, Receptors, G-Protein-Coupled metabolism, Diatoms enzymology, Endoplasmic Reticulum enzymology, N-Acetylglucosaminyltransferases metabolism, Polysaccharides metabolism
- Abstract
N-glycosylation, a major co- and post-translational event in the synthesis of proteins in eukaryotes, is unknown in aquatic photosynthetic microalgae. In this paper, we describe the N-glycosylation pathway in the diatom Phaeodactylum tricornutum. Bio-informatic analysis of its genome revealed the presence of a complete set of sequences potentially encoding for proteins involved in the synthesis of the lipid-linked Glc(3)Man(9)GlcNAc(2)-PP-dolichol N-glycan, some subunits of the oligosaccharyltransferase complex, as well as endoplasmic reticulum glucosidases and chaperones required for protein quality control and, finally, the α-mannosidase I involved in the trimming of the N-glycan precursor into Man-5 N-glycan. Moreover, one N-acetylglucosaminyltransferase I, a Golgi glycosyltransferase that initiates the synthesis of complex type N-glycans, was predicted in the P. tricornutum genome. We demonstrated that this gene encodes for an active N-acetylglucosaminyltransferase I, which is able to restore complex type N-glycans maturation in the Chinese hamster ovary Lec1 mutant, defective in its endogeneous N-acetylglucosaminyltransferase I. Consistent with these data, the structural analyses of N-linked glycans demonstrated that P. tricornutum proteins carry mainly high mannose type N-glycans ranging from Man-5 to Man-9. Although representing a minor glycan population, paucimannose N-glycans were also detected, suggesting the occurrence of an N-acetylglucosaminyltransferase I-dependent maturation of N-glycans in this diatom. more...
- Published
- 2011
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23. Antiproliferative activity of violaxanthin isolated from bioguided fractionation of Dunaliella tertiolecta extracts.
- Author
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Pasquet V, Morisset P, Ihammouine S, Chepied A, Aumailley L, Berard JB, Serive B, Kaas R, Lanneluc I, Thiery V, Lafferriere M, Piot JM, Patrice T, Cadoret JP, and Picot L
- Subjects
- Apoptosis drug effects, Cell Line, Tumor, Chromatography, High Pressure Liquid, DNA Fragmentation drug effects, Humans, Xanthophylls isolation & purification, Xanthophylls pharmacology, Antineoplastic Agents pharmacology, Cell Proliferation drug effects, Microalgae chemistry
- Abstract
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT dichloromethane extract exhibited a strong anti-proliferative activity on MCF-7 and LNCaP cells, and was further fractionated and sub-fractionated by RP-HPLC. High resolution mass spectrometry and spectrophotometric analysis unequivocally identified violaxanthin as the most antiproliferative molecule present in DT DCM extract. Violaxanthin purified from DT induced MCF-7 dose-dependent growth inhibition in continuous and discontinuous treatments, at concentrations as low as 0.1 μg·mL⁻¹ (0.17 μM). Phosphatidylserine exposure, typical of early apoptosis, was observed after 48 h treatment at 8 μg·mL⁻¹ (13.3 μM) but no DNA fragmentation, characteristic of late apoptosis steps, could be detected even after 72 h treatment at 40 μg·mL⁻¹ (66.7 μM). Taken together, our results demonstrate the strong antiproliferative activity of violaxanthin on one human mammary cancer cell line, and suggest that studying the pharmacology of violaxanthin and pharmacomodulated derivatives on cancer cells may allow potent antiproliferative drugs to be obtained. more...
- Published
- 2011
- Full Text
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24. Digital expression profiling of novel diatom transcripts provides insight into their biological functions.
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Maheswari U, Jabbari K, Petit JL, Porcel BM, Allen AE, Cadoret JP, De Martino A, Heijde M, Kaas R, La Roche J, Lopez PJ, Martin-Jézéquel V, Meichenin A, Mock T, Schnitzler Parker M, Vardi A, Armbrust EV, Weissenbach J, Katinka M, and Bowler C more...
- Subjects
- Carbon Dioxide metabolism, Environment, Expressed Sequence Tags, Iron metabolism, Molecular Sequence Data, Nitrogen metabolism, Salinity, Silicates metabolism, Temperature, Adaptation, Physiological genetics, Diatoms genetics, Gene Expression Profiling methods, Gene Expression Regulation physiology, RNA, Messenger analysis
- Abstract
Background: Diatoms represent the predominant group of eukaryotic phytoplankton in the oceans and are responsible for around 20% of global photosynthesis. Two whole genome sequences are now available. Notwithstanding, our knowledge of diatom biology remains limited because only around half of their genes can be ascribed a function based onhomology-based methods. High throughput tools are needed, therefore, to associate functions with diatom-specific genes., Results: We have performed a systematic analysis of 130,000 ESTs derived from Phaeodactylum tricornutum cells grown in 16 different conditions. These include different sources of nitrogen, different concentrations of carbon dioxide, silicate and iron, and abiotic stresses such as low temperature and low salinity. Based on unbiased statistical methods, we have catalogued transcripts with similar expression profiles and identified transcripts differentially expressed in response to specific treatments. Functional annotation of these transcripts provides insights into expression patterns of genes involved in various metabolic and regulatory pathways and into the roles of novel genes with unknown functions. Specific growth conditions could be associated with enhanced gene diversity, known gene product functions, and over-representation of novel transcripts. Comparative analysis of data from the other sequenced diatom, Thalassiosira pseudonana, helped identify several unique diatom genes that are specifically regulated under particular conditions, thus facilitating studies of gene function, genome annotation and the molecular basis of species diversity., Conclusions: The digital gene expression database represents a new resource for identifying candidate diatom-specific genes involved in processes of major ecological relevance. more...
- Published
- 2010
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25. The Phaeodactylum genome reveals the evolutionary history of diatom genomes.
- Author
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Bowler C, Allen AE, Badger JH, Grimwood J, Jabbari K, Kuo A, Maheswari U, Martens C, Maumus F, Otillar RP, Rayko E, Salamov A, Vandepoele K, Beszteri B, Gruber A, Heijde M, Katinka M, Mock T, Valentin K, Verret F, Berges JA, Brownlee C, Cadoret JP, Chiovitti A, Choi CJ, Coesel S, De Martino A, Detter JC, Durkin C, Falciatore A, Fournet J, Haruta M, Huysman MJ, Jenkins BD, Jiroutova K, Jorgensen RE, Joubert Y, Kaplan A, Kröger N, Kroth PG, La Roche J, Lindquist E, Lommer M, Martin-Jézéquel V, Lopez PJ, Lucas S, Mangogna M, McGinnis K, Medlin LK, Montsant A, Oudot-Le Secq MP, Napoli C, Obornik M, Parker MS, Petit JL, Porcel BM, Poulsen N, Robison M, Rychlewski L, Rynearson TA, Schmutz J, Shapiro H, Siaut M, Stanley M, Sussman MR, Taylor AR, Vardi A, von Dassow P, Vyverman W, Willis A, Wyrwicz LS, Rokhsar DS, Weissenbach J, Armbrust EV, Green BR, Van de Peer Y, and Grigoriev IV more...
- Subjects
- DNA, Algal analysis, Genes, Bacterial genetics, Molecular Sequence Data, Protein Structure, Tertiary, Sequence Homology, Amino Acid, Signal Transduction, Diatoms genetics, Evolution, Molecular, Genome genetics
- Abstract
Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes ( approximately 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans. more...
- Published
- 2008
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26. [Microalgae as cell factories producing recombinant commercial proteins].
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Cadoret JP, Bardor M, Lerouge P, Cabigliera M, Henriquez V, and Carlier A
- Subjects
- Animals, Chloroplasts physiology, Commerce, Eukaryota genetics, Gene Silencing, Mice, Mice, Transgenic, Models, Biological, Eukaryota physiology, Proteins genetics, Recombinant Proteins biosynthesis
- Abstract
Extraction of natural substances and chemical synthesis are the main sources of pharmaceutical molecules. When possible, one may transfer the gene of the molecule in living cells creating individual factories producing on demand and in a safe way the requested molecule. Today, bacteria, yeast, mammalian cells and plants constitute the main plate-forms for various commercial products. Microalgae present numerous advantages and could offer a powerful tool for the production of commercial molecules in a near future. more...
- Published
- 2008
- Full Text
- View/download PDF
27. [Lipid biofuel production with microalgae: potential and challenges].
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Cadoret JP and Bernard O
- Subjects
- Animals, Bioreactors economics, Bioreactors microbiology, Biotechnology economics, Carbon Dioxide metabolism, Chemical Industry economics, Cyanobacteria growth & development, Cyanobacteria metabolism, Eukaryota growth & development, Fatty Acids metabolism, Forecasting, Industrial Microbiology economics, Industrial Microbiology instrumentation, Photosynthesis, Plant Oils, Biotechnology methods, Chemical Industry methods, Energy-Generating Resources economics, Eukaryota metabolism, Industrial Microbiology methods, Industrial Oils economics
- Abstract
Microalgae can accumulate fatty acids up to 80% of their dry weight (Chisti 2007). As a consequence the yield per hectare could be higher by a factor of 30 compared to terrestrial oleaginous species. Biodiversity of microalgae is enormous. It is estimated that there are between 200 000 and several million species. Such diversity is an unexplored potential for research and industry. In comparison to terrestrial oleaginous species, microalgae have many characteristics addressing environmental problems with a drastically enhanced oil production. Microalgae are currently generating mediatic enthusiasm, and many start-ups are investing this niche. Nevertheless there are still locks to undo via upstream search, before the expected returns and costs are met and before these technologies can be developed at a large scale. more...
- Published
- 2008
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- View/download PDF
28. Cultivated microalgae and the carotenoid fucoxanthin from Odontella aurita as potent anti-proliferative agents in bronchopulmonary and epithelial cell lines.
- Author
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Moreau D, Tomasoni C, Jacquot C, Kaas R, Le Guedes R, Cadoret JP, Muller-Feuga A, Kontiza I, Vagias C, Roussis V, and Roussakis C
- Abstract
The antiproliferative activities of several extracts from cultivated microalgae in France have been studied against bronchopulmonary and epithelial cell lines, respectively (A549, NSCLC-N6 and SRA 01/04). The algal extracts, of Diatomae (Odontella aurita, Chaetoseros sp.), as well as of Haptophyceae: Isochrisys aff. galbana, appeared as the most active among all the assayed species, expressing a broad spectrum of in vitro antiproliferative activity of well-differentiated pathologic cells such as NSCLC-N6 by terminal differentiation. Bio-guided fractionation of the above referred extracts, led us to the isolation, of the carotenoid fucoxanthin. Fucoxanthin has been structurally determined, through modern spectral means and has been studied separately for its activities. more...
- Published
- 2006
- Full Text
- View/download PDF
29. Crassostrea gigas ferritin: cDNA sequence analysis for two heavy chain type subunits and protein purification.
- Author
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Durand JP, Goudard F, Pieri J, Escoubas JM, Schreiber N, and Cadoret JP
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Binding Sites genetics, Blotting, Northern, Chromatography, High Pressure Liquid, Chromatography, Ion Exchange, DNA, Complementary chemistry, DNA, Complementary genetics, Electrophoresis, Polyacrylamide Gel, Ferritins chemistry, Ferritins isolation & purification, Gene Expression Profiling, Iron-Regulatory Proteins metabolism, Molecular Sequence Data, Multigene Family genetics, Phylogeny, Protein Subunits chemistry, Protein Subunits genetics, Protein Subunits isolation & purification, RNA, Messenger genetics, RNA, Messenger metabolism, Sequence Alignment, Sequence Analysis, DNA, Sequence Analysis, Protein, Sequence Homology, Amino Acid, Sequence Homology, Nucleic Acid, Ferritins genetics, Ostreidae genetics
- Abstract
Ferritin has been shown as being the principal iron storage in the majority of living organisms. In marine species, ferritin is also involved in high-level accumulation of (210)Po. As part of our work on the investigation of these radionuclides' concentration in natural environment, ferritin was searched at the gene and protein level. Ferritin was purified from the visceral mass of the oyster Crassostrea gigas by ion-exchange chromatography and HPLC. SDS-PAGE revealed one band of 20 kDa. An Expressed Sequence Tag (EST) library was screened and led to the identification of two complementary DNA (cDNA) involved in ferritin subunit expression. The complete coding sequences and the untranslated regions (UTRs) of the two genes were obtained and a 5' Rapid Amplification of cDNA Ends (RACE) was used to obtain the two iron-responsive elements (IREs) with the predicted stem-loop structures usually present in the 5'-UTR of ferritin mRNA. Sequence alignment in amino acid of the two new cDNA showed an identity with Pinctada fucata (85.4-88.3%), Lymnaea stagnalis (79.3-82.2%) and Helix pomatia (79.1-79.1%). The residues responsible for the ferroxidase center, conserved in all vertebrate H-ferritins, are present in the two oyster ferritin subunits. Oyster ferritins do not present the special characteristics of other invertebrate ferritins like insect ferritins but have some functional similarities with the vertebrate H chains ferritin. more...
- Published
- 2004
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30. Immune gene discovery by expressed sequence tags generated from hemocytes of the bacteria-challenged oyster, Crassostrea gigas.
- Author
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Gueguen Y, Cadoret JP, Flament D, Barreau-Roumiguière C, Girardot AL, Garnier J, Hoareau A, Bachère E, and Escoubas JM
- Subjects
- Animals, Bacteria immunology, Blood Cells cytology, Cell Adhesion Molecules genetics, Cell Division genetics, DNA, Complementary chemistry, DNA, Complementary genetics, Endopeptidases genetics, Ferritins genetics, Gene Expression Regulation immunology, Metallothionein genetics, Ostreidae immunology, Sequence Analysis, DNA, Tissue Inhibitor of Metalloproteinases genetics, Expressed Sequence Tags, Hemocytes metabolism, Immunity, Innate genetics, Ostreidae genetics
- Abstract
An expressed sequence tag program was undertaken to isolate genes involved in defense mechanisms of the Pacific oyster, Crassostrea gigas. Putative function could be assigned to 54% of the 1142 sequenced cDNAs. We built a public database where all EST information are accessible through numerous search profiles (http://www.ifremer.fr/GigasBase). Based on sequence similarities we identified 20 genes that may be implicated in immune function. We investigated the expression of four of these genes during bacterial challenge of oysters. Three of them were induced in response to challenge lending support to their involvement in oyster immunity. Moreover, four other genes were highly homologous to components of the NF-kappa B signaling pathway which is involved in innate immune response in Drosophila and mammals. Altogether, our results open a new way to investigate the immune response in mollusks. more...
- Published
- 2003
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31. Infection of cultured embryo cells of the pacific oyster, Crassostrea gigas, by pantropic retroviral vectors.
- Author
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Boulo V, Cadoret JP, Shike H, Shimizu C, Miyanohara A, and Burns JC
- Subjects
- Animals, Cell Adhesion, Cell Culture Techniques, Cell Survival, Embryo, Nonmammalian virology, Genes, Reporter, Heart embryology, Luciferases biosynthesis, Luciferases genetics, Myocardium cytology, Osmotic Pressure, Ostreidae cytology, Ostreidae virology, Promoter Regions, Genetic, Recombinant Proteins biosynthesis, Retroviridae physiology, Cells, Cultured, Embryo, Nonmammalian cytology, Genetic Vectors, Ostreidae embryology, Retroviridae genetics
- Abstract
The inability to stably introduce and express foreign genes has hampered basic research in molluscan species. We cultured cells from dissociated embryos of the Pacific oyster, Crassostrea gigas, and infected these primary cultures with pantropic retroviral vectors containing the envelope glycoprotein of vesicular stomatitis virus. Luciferase transgene expression mediated by different heterologous promoters was demonstrated for at least 9 d after infection of the cells. Surprisingly, the promoter reproducibly mediating the highest level of luciferase expression was the retroviral promoter (U3 region of long terminal repeat) from the Moloney murine leukemia virus. The infection efficiency using a low multiplicity of infection (0.05) was estimated by quantitative polymerase chain reaction to be between 0.1-0.5%. This system will facilitate studies of gene expression and regulation and should be widely applicable to other molluscan species. more...
- Published
- 2000
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32. Transient expression assays with the proximal promoter of a newly characterized actin gene from the oyster Crassostrea gigas.
- Author
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Cadoret JP, Debón R, Cornudella L, Lardans V, Morvan A, Roch P, and Boulo V
- Subjects
- Actins chemistry, Amino Acid Sequence, Animals, Base Sequence, Cells, Cultured, Cloning, Molecular, DNA-Binding Proteins genetics, Gene Expression Regulation, Genes, Reporter, Molecular Sequence Data, Mutation, Nuclear Proteins genetics, Serum Response Factor, Transfection, Actins genetics, Ostreidae genetics, Promoter Regions, Genetic
- Abstract
We undertook the characterization of an actin gene and its proximal promoter in the oyster Crassostrea gigas. A complete actin cDNA was identified, sequenced and its amino acid sequence deduced. Comparative analysis showed a high homology with actin of other species and that this gene is closer to the cytoplasmic form of actins than to the muscle type. A probe derived from the 5'-untranslated region of the cDNA was then used to isolate the actin gene from a genomic library. The gene was sequenced and shown to contain a single 643 bp intron. A 1670 bp fragment upstream from the open reading frame was isolated and sequenced. This upstream region displays typical features of actins such as a serum response element (CarG box). This fragment was cloned into the promoterless vector pGL3-basic and the resulting construct was transfected into cells of dissociated oyster heart primary cultures. Its capacity to express the luciferase in this in vitro homologous system was monitored and showed high expression levels. This is the first complete actin sequence reported so far for the oyster C. gigas and its promoter is the first available among bivalves. more...
- Published
- 1999
- Full Text
- View/download PDF
33. Promoters from Drosophila heat shock protein and cytomegalovirus drive transient expression of luciferase introduced by particle bombardment into embryos of the oyster Crassostrea gigas.
- Author
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Cadoret JP, Boulo V, Gendreau S, and Mialhe E
- Subjects
- Animals, Cell Survival, Cytomegalovirus genetics, Drosophila genetics, Gene Expression Regulation genetics, Genes, Reporter genetics, Genetic Vectors, Kinetics, Luciferases metabolism, Ostreidae embryology, Ovum metabolism, Temperature, Zygote metabolism, Biolistics methods, HSP70 Heat-Shock Proteins genetics, Luciferases genetics, Ostreidae genetics, Promoter Regions, Genetic
- Abstract
Using high velocity particle bombardment, we transferred a reporter gene into early stages of the oyster Crassostrea gigas and showed the expression of the introduced genes in these embryos at later stages of development. We tested two promoters: (1) the heat shock protein 70 promoter of Drosophila; (2) the cytomegalovirus early promoter, both linked to the luciferase reporter gene. The hsp 70-luc (pDrluc) construct allowed an expression level up to 55-fold higher than the control in a heat inducible fashion. The CMV-luc (pCMVL) construct constitutively gave a 4-fold higher expression than the control. This confirms the suitability of particle bombardment for transfecting genes into eggs, zygotes and trochopores of bivalves and demonstrates the functionality of two heterologous expression vectors in C. gigas. more...
- Published
- 1997
- Full Text
- View/download PDF
34. Microinjection of bivalve eggs: application in genetics.
- Author
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Cadoret JP, Gendreau S, Delecheneau JM, Rousseau C, and Mialhe E
- Subjects
- Animals, Blastocyst cytology, Cell Survival, Cytomegalovirus, Embryo, Nonmammalian cytology, Female, Fertilization in Vitro methods, Genetic Vectors, Male, Microinjections, Promoter Regions, Genetic, Zygote physiology, beta-Galactosidase biosynthesis, beta-Galactosidase genetics, Bivalvia physiology, Blastocyst physiology, Embryo, Nonmammalian physiology, Oocytes physiology, Ostreidae physiology, Recombinant Proteins biosynthesis
- Abstract
New strategies for embryonic manipulation have been developed in recent years through plant and animal research. However, research on marine invertebrate embryos has suffered from a lack of basic tools, such as microinjection. Here we present a technique developed for microinjecting eggs and embryos of the oyster Crassostrea gigas and the mussel Mytilus edulis. In experimental trials, approximately 40% of microinjected embryos survived. This technique was used to microinject beta-galactosidase, for which specific detection techniques were developed. A reporter construct (CMV-beta) based on a promoter of cytomegalovirus linked to the beta-galactosidase-encoding gene was then microinjected, and the expression level of this construct was monitored. The suitability of this technique is discussed in terms of its application to the manipulation of bivalve mollusks in pathology and genetics. more...
- Published
- 1997
35. Nucleotide and deduced amino acid sequences of Biomphalaria glabrata actin cDNA.
- Author
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Lardans V, Ringaut V, Duclermortier P, Cadoret JP, and Dissous C
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Blotting, Northern, Cloning, Molecular, Cytoskeleton, DNA, Complementary, Molecular Sequence Data, Promoter Regions, Genetic, Sequence Analysis, Sequence Homology, Amino Acid, Actins genetics, Biomphalaria genetics
- Abstract
The complete nucleotide sequence of Biomphalaria glabrata actin has been cloned by PCR amplification and screening of a cDNA library of Biomphalaria glabrata. The comparison of the deduced amino acid sequence with other actins suggests that a cytoskeletal form of the protein has been cloned. more...
- Published
- 1997
- Full Text
- View/download PDF
36. Transient expression of luciferase reporter gene after lipofection in oyster (Crassostrea gigas) primary cell cultures.
- Author
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Boulo V, Cadoret JP, Le Marrec F, Dorange G, and Miahle E
- Subjects
- Animals, Cells, Cultured, Cytomegalovirus genetics, Drosophila, Genes, Immediate-Early genetics, HSP70 Heat-Shock Proteins genetics, Liposomes, Luciferases metabolism, Myocardium cytology, Ostreidae cytology, Promoter Regions, Genetic, Simian virus 40 genetics, Transcription, Genetic, Gene Expression, Genes, Reporter genetics, Luciferases genetics, Ostreidae genetics, Transfection methods
- Abstract
Transient expression of the luciferase gene, under transcriptional control of several heterologous promoters, was obtained in heart primary cell cultures of the Pacific oyster, Crassostrea gigas. Drosophila heat shock protein 70 promoter (hsp70), cytomegalovirus, and simian virus early promoters, controlling the luciferase gene, were transfected into the cell cultures using liposomes. Two culture media were used to establish primary cell cultures and tested as transfection media. Parameters such as the quantity of DNA and the ratio of DNA to liposome were analyzed to define the best transfection conditions. In oysters, the Drosophila inducible hsp70 promoter behaved in a way similar to that observed in other animal species. Moreover, for this study, hsp70 was more efficient than the cytomegalovirus and simian virus promoters. more...
- Published
- 1996
37. Future of biotechnology-based control of disease in marine invertebrates.
- Author
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Mialhe E, Bachere E, Boulo V, Cadoret JP, Rousseau C, Cedeño V, Saraiva E, Carrera L, Calderon J, and Colwell RR
- Subjects
- Animals, Decapoda microbiology, Immunity, Innate genetics, Molecular Probe Techniques, Mollusca microbiology, Transformation, Genetic, Animal Diseases prevention & control, Aquaculture trends, Biotechnology trends, Communicable Diseases veterinary, Invertebrates microbiology, Marine Biology trends
- Abstract
Infectious disease is the single most devastating problem in mollusc and shrimp aquaculture. Pathogens causing the greatest problems have been identified as viruses, prokaryotes, and protozoans. Two approaches employing methods of biotechnology have been proposed to prevent, manage, and control mollusc and shrimp diseases. The first is development of a diagnostic scheme for detection and identification of pathogens, using molecular probes. This offers the opportunity for prophylactic measures to be taken. Molecular probes have been prepared for the major pathogens of molluscs, but in the case of shrimp pathogens, only a few are available. Monoclonal antibodies have also been prepared and are used in immunodiagnosis, e.g., immunofluorescence detection. Such diagnostic tools are relatively new to aquaculture, but have enormous potential. A second approach to the control of disease in marine invertebrates, notably shrimp, involves use of genetically transformed strains resistant to specific pathogens. Pathogen-resistant transgenic animals have been developed, but such research has only just begun for molluscs and shrimp. Transfection methods applied to mollusc and shrimp embryos have been successful, with preliminary data showing efficiency of heterologous promoters in controlling expression of reporter genes. Other transformation systems also show promise, including transposable elements and densoviruses. more...
- Published
- 1995
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