29 Hits in 0.85 sec

Feuille de route IFB 2021-2028: MUDIS4LS [article]

Jacques Van Helden, Julien Seiler, Gildas Le Corguillé, Claudine Médigue, IFB Teams
2021 Zenodo  
M ANAGEMENT FRAMEWORK M ANAGEMENT Relevant experience of the project manager The project is managed by a team composed of Jacques van Helden (scientific management), Gildas Le Corguillé and Julien  ...  ABiMS ( ) Corresponding people: Corre Erwan, Gildas Le Corguillé The mission of the ABiMS platform is to assist researchers of the marine community and, more broadly, of the  ... 
doi:10.5281/zenodo.5229330 fatcat:speqf7rjcjc5hiaqeemlmvjg7m

How Egg Case Proteins Can Protect Cuttlefish Offspring?

Valérie Cornet, Joël Henry, Didier Goux, Emilie Duval, Benoit Bernay, Gildas Le Corguillé, Erwan Corre, Céline Zatylny-Gaudin, Michael Schubert
2015 PLoS ONE  
Sepia officinalis egg protection is ensured by a complex capsule produced by the female accessory genital glands and the ink bag. Our study is focused on the proteins constituting the main egg case. De novo transcriptomes from female genital glands provided essential databases for protein identification. A proteomic approach in SDS-PAGE coupled with MS unveiled a new egg case protein family: SepECPs, for Sepia officinalis Egg Case Proteins. N-glycosylation was demonstrated by PAS staining
more » ... GE gels. These glycoproteins are mainly produced in the main nidamental glands. SepECPs share high sequence homology, especially in the signal peptide and the three cysteine-rich domains. SepECPs have a high number of cysteines, with conserved motifs involved in 3D-structure. SDS-PAGE showed that SepECPs could form dimers; this result was confirmed by TEM observations, which also revealed a protein network. This network is similar to the capsule network, and it associates these structural proteins with polysaccharides, melanin and bacteria to form a tight mesh. Its hardness and elasticity provide physical protection to the embryo. In addition, SepECPs also have bacteriostatic antimicrobial activity on GRAM-bacteria. By observing the SepECP / Vibrio aestuarianus complex in SEM, we demonstrated the ability of these proteins to agglomerate bacteria and thus inhibit their growth. These original proteins identified from the outer egg case ensure the survival of the species by providing physical and chemical protection to the embryos released in the environment without any maternal protection.
doi:10.1371/journal.pone.0132836 pmid:26168161 pmcid:PMC4500399 fatcat:w4lyrgm7mzbbrbropssh5cks2y

Genetic regulation of life cycle transitions in the brown alga Ectocarpus

Susana M. Coelho, Olivier Godfroy, Alok Arun, Gildas Le Corguillé, Akira F. Peters, J. Mark Cock
2011 Plant Signalling & Behavior  
Coelho, 1,2 Olivier Godfroy, 1,2 Alok Arun, 1,2 Gildas Le Corguillé, 3 Modifications to life cycle structures may have played an important adaptive role during the evolution of some major eukaryotic  ... 
doi:10.4161/psb.6.11.17737 pmid:22067105 pmcid:PMC3329369 fatcat:faps5tqm2bfzfbvpxtmsuquniq

Translatome analysis at the egg-to-embryo transition in sea urchin

Héloïse Chassé, Julie Aubert, Sandrine Boulben, Gildas Le Corguillé, Erwan Corre, Patrick Cormier, Julia Morales
2018 Nucleic Acids Research  
Early embryogenesis relies on the translational regulation of maternally stored mRNAs. In sea urchin, fertilization triggers a dramatic rise in translation activity, necessary for the onset of cell division. Here, the full spectrum of the mRNAs translated upon fertilization was investigated by polysome profiling and sequencing. The translatome of the early sea urchin embryo gave a complete picture of the polysomal recruitment dynamics following fertilization. Our results indicate that only a
more » ... set of maternal mRNAs were selectively recruited onto polysomes, with overrepresented functional categories in the translated set. The increase in translation upon fertilization depends on the formation of translation initiation complexes following mTOR pathway activation. Surprisingly, mTOR pathway inhibition differentially affected polysomal recruitment of the newly translated mR-NAs, which thus appeared either mTOR-dependent or mTOR-independent. Therefore, our data argue for an alternative to the classical cap-dependent model of translation in early development. The identification of the mRNAs translated following fertilization helped assign translational activation events to specific mRNAs. This translatome is the first step to a comprehensive analysis of the molecular mechanisms governing translation upon fertilization and the translational regulatory networks that control the egg-to-embryo transition as well as the early steps of embryogenesis.
doi:10.1093/nar/gky258 pmid:29660001 pmcid:PMC5961321 fatcat:65utzppmprgyzb3eyrnzz2rltu

CyanoLyase: a database of phycobilin lyase sequences, motifs and functions

Anthony Bretaudeau, François Coste, Florian Humily, Laurence Garczarek, Gildas Le Corguillé, Christophe Six, Morgane Ratin, Olivier Collin, Wendy M. Schluchter, Frédéric Partensky
2012 Nucleic Acids Research  
CyanoLyase ( is a manually curated sequence and motif database of phycobilin lyases and related proteins. These enzymes catalyze the covalent ligation of chromophores (phycobilins) to specific binding sites of phycobiliproteins (PBPs). The latter constitute the building bricks of phycobilisomes, the major light-harvesting systems of cyanobacteria and red algae. Phycobilin lyases sequences are poorly annotated in public databases. Sequences included in CyanoLyase
more » ... ere retrieved from all available genomes of these organisms and a few others by similarity searches using biochemically characterized enzyme sequences and then classified into 3 clans and 32 families. Amino acid motifs were computed for each family using Protomata learner. CyanoLyase also includes BLAST and a novel pattern matching tool (Protomatch) that allow users to rapidly retrieve and annotate lyases from any new genome. In addition, it provides phylogenetic analyses of all phycobilin lyases families, describes their function, their presence/absence in all genomes of the database (phyletic profiles) and predicts the chromophorylation of PBPs in each strain. The site also includes a thorough bibliography about phycobilin lyases and genomes included in the database. This resource should be useful to scientists and companies interested in natural or artificial PBPs, which have a number of biotechnological applications, notably as fluorescent markers.
doi:10.1093/nar/gks1091 pmid:23175607 pmcid:PMC3531064 fatcat:dimmf6wycbd57l3robs334dbla

Prochlorococcus and Synechococcus have Evolved Different Adaptive Mechanisms to Cope with Light and UV Stress

Daniella Mella-Flores, Christophe Six, Morgane Ratin, Frédéric Partensky, Christophe Boutte, Gildas Le Corguillé, Dominique Marie, Nicolas Blot, Priscillia Gourvil, Christian Kolowrat, Laurence Garczarek
2012 Frontiers in Microbiology  
Prochlorococcus and Synechococcus, which numerically dominate vast oceanic areas, are the two most abundant oxygenic phototrophs on Earth. Although they require solar energy for photosynthesis, excess light and associated high UV radiations can induce high levels of oxidative stress that may have deleterious effects on their growth and productivity. Here, we compared the photophysiologies of the model strains Prochlorococcus marinus PCC 9511 and Synechococcus sp. WH7803 grown under a
more » ... light/dark cycle of high visible light supplemented or not with UV. Prochlorococcus exhibited a higher sensitivity to photoinactivation than Synechococcus under both conditions, as shown by a larger drop of photosystem II (PSII) quantum yield at noon and different diel patterns of the D1 protein pool. In the presence of UV, the PSII repair rate was significantly depressed at noon in Prochlorococcus compared to Synechococcus. Additionally, Prochlorococcus was more sensitive than Synechococcus to oxidative stress, as shown by the different degrees of PSII photoinactivation after addition of hydrogen peroxide. A transcriptional analysis also revealed dramatic discrepancies between the two organisms in the diel expression patterns of several genes involved notably in the biosynthesis and/or repair of photosystems, light-harvesting complexes, CO 2 fixation as well as protection mechanisms against light, UV, and oxidative stress, which likely translate profound differences in their light-controlled regulation. Altogether our results suggest that while Synechococcus has developed efficient ways to cope with light and UV stress, Prochlorococcus cells seemingly survive stressful hours of the day by launching a minimal set of protection mechanisms and by temporarily bringing down several key metabolic processes. This study provides unprecedented insights into understanding the distinct depth distributions and dynamics of these two picocyanobacteria in the field.
doi:10.3389/fmicb.2012.00285 pmid:23024637 pmcid:PMC3441193 fatcat:sjka4ocj7zd43p54zstlgurgxu

Tracking a refined eIF4E-binding motif reveals Angel1 as a new partner of eIF4E

Pauline Gosselin, Yvan Martineau, Julia Morales, Mirjam Czjzek, Virginie Glippa, Isabelle Gauffeny, Emmanuelle Morin, Gildas Le Corguillé, Stephane Pyronnet, Patrick Cormier, Bertrand Cosson
2013 Nucleic Acids Research  
The initiation factor 4E (eIF4E) is implicated in most of the crucial steps of the mRNA life cycle and is recognized as a pivotal protein in gene regulation. Many of these roles are mediated by its interaction with specific proteins generally known as eIF4Einteracting partners (4E-IPs), such as eIF4G and 4E-BP. To screen for new 4E-IPs, we developed a novel approach based on structural, in silico and biochemical analyses. We identified the protein Angel1, a member of the CCR4 deadenylase
more » ... Immunoprecipitation experiments provided evidence that Angel1 is able to interact in vitro and in vivo with eIF4E. Point mutation variants of Angel1 demonstrated that the interaction of Angel1 with eIF4E is mediated through a consensus eIF4Ebinding motif. Immunofluorescence and cell fractionation experiments showed that Angel1 is confined to the endoplasmic reticulum and Golgi apparatus, where it partially co-localizes with eIF4E and eIF4G, but not with 4E-BP. Furthermore, manipulating Angel1 levels in living cells had no effect on global translation rates, suggesting that the protein has a more specific function. Taken together, our results illustrate that we developed a powerful method for identifying new eIF4E partners and open new perspectives for understanding eIF4E-specific regulation.
doi:10.1093/nar/gkt569 pmid:23814182 pmcid:PMC3763552 fatcat:dwpjepvavnaahnvr244zcaumgq

Seascape genomics reveals population isolation in the reef-building honeycomb worm, Sabellaria alveolata (L.)

Anna P. Muir, Stanislas F. Dubois, Rebecca E. Ross, Louise B. Firth, Antony M. Knights, Fernando P. Lima, Rui Seabra, Erwan Corre, Gildas Le Corguillé, Flavia L. D. Nunes
2020 BMC Evolutionary Biology  
Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried
more » ... t RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.
doi:10.1186/s12862-020-01658-9 pmid:32778052 fatcat:tegb3osfzvgbfevegjrya7cw4m

Ultraviolet stress delays chromosome replication in light/dark synchronized cells of the marine cyanobacterium Prochlorococcus marinus PCC9511

Christian Kolowrat, Frédéric Partensky, Daniella Mella-Flores, Gildas Le Corguillé, Christophe Boutte, Nicolas Blot, Morgane Ratin, Martial Ferréol, Xavier Lecomte, Priscillia Gourvil, Jean-François Lennon, David M Kehoe (+1 others)
2010 BMC Microbiology  
The marine cyanobacterium Prochlorococcus is very abundant in warm, nutrient-poor oceanic areas. The upper mixed layer of oceans is populated by high light-adapted Prochlorococcus ecotypes, which despite their tiny genome (~1.7 Mb) seem to have developed efficient strategies to cope with stressful levels of photosynthetically active and ultraviolet (UV) radiation. At a molecular level, little is known yet about how such minimalist microorganisms manage to sustain high growth rates and avoid
more » ... ntially detrimental, UV-induced mutations to their DNA. To address this question, we studied the cell cycle dynamics of P. marinus PCC9511 cells grown under high fluxes of visible light in the presence or absence of UV radiation. Near natural light-dark cycles of both light sources were obtained using a custom-designed illumination system (cyclostat). Expression patterns of key DNA synthesis and repair, cell division, and clock genes were analyzed in order to decipher molecular mechanisms of adaptation to UV radiation. Results: The cell cycle of P. marinus PCC9511 was strongly synchronized by the day-night cycle. The most conspicuous response of cells to UV radiation was a delay in chromosome replication, with a peak of DNA synthesis shifted about 2 h into the dark period. This delay was seemingly linked to a strong downregulation of genes governing DNA replication (dnaA) and cell division (ftsZ, sepF), whereas most genes involved in DNA repair (such as recA, phrA, uvrA, ruvC, umuC) were already activated under high visible light and their expression levels were only slightly affected by additional UV exposure. Conclusions: Prochlorococcus cells modified the timing of the S phase in response to UV exposure, therefore reducing the risk that mutations would occur during this particularly sensitive stage of the cell cycle. We identified several possible explanations for the observed timeshift. Among these, the sharp decrease in transcript levels of the dnaA gene, encoding the DNA replication initiator protein, is sufficient by itself to explain this response, since DNA synthesis starts only when the cellular concentration of DnaA reaches a critical threshold. However, the observed response likely results from a more complex combination of UV-altered biological processes.
doi:10.1186/1471-2180-10-204 pmid:20670397 pmcid:PMC2921402 fatcat:ajqqgsfyerhgfkyqthiwbtqeby

A sequence-tagged genetic map for the brown alga Ectocarpus siliculosus provides large-scale assembly of the genome sequence

Svenja Heesch, Ga Youn Cho, Akira F. Peters, Gildas Le Corguillé, Cyril Falentin, Gilles Boutet, Solène Coëdel, Claire Jubin, Gaelle Samson, Erwan Corre, Susana M. Coelho, J. Mark Cock
2010 New Phytologist  
Charrier B, Coelho SM, Le Bail A, Tonon T, Michel G, Potin P, Kloareg B, Boyen C, Peters AF, Cock JM. 2008.  ... 
doi:10.1111/j.1469-8137.2010.03273.x pmid:20456050 fatcat:swugzpexljabrnasutl4ez523a

Synergic Effects of Temperature and Irradiance on the Physiology of the Marine Synechococcus Strain WH7803

Ulysse Guyet, Ngoc A. Nguyen, Hugo Doré, Julie Haguait, Justine Pittera, Maël Conan, Morgane Ratin, Erwan Corre, Gildas Le Corguillé, Loraine Brillet-Guéguen, Mark Hoebeke, Christophe Six (+5 others)
2020 Frontiers in Microbiology  
Understanding how microorganisms adjust their metabolism to maintain their ability to cope with short-term environmental variations constitutes one of the major current challenges in microbial ecology. Here, the best physiologically characterized marine Synechococcus strain, WH7803, was exposed to modulated light/dark cycles or acclimated to continuous high-light (HL) or low-light (LL), then shifted to various stress conditions, including low (LT) or high temperature (HT), HL and ultraviolet
more » ... ) radiations. Physiological responses were analyzed by measuring time courses of photosystem (PS) II quantum yield, PSII repair rate, pigment ratios and global changes in gene expression. Previously published membrane lipid composition were also used for correlation analyses. These data revealed that cells previously acclimated to HL are better prepared than LL-acclimated cells to sustain an additional light or UV stress, but not a LT stress. Indeed, LT seems to induce a synergic effect with the HL treatment, as previously observed with oxidative stress. While all tested shift conditions induced the downregulation of many photosynthetic genes, notably those encoding PSI, cytochrome b6/f and phycobilisomes, UV stress proved to be more deleterious for PSII than the other treatments, and full recovery of damaged PSII from UV stress seemed to involve the neo-synthesis of a fairly large number of PSII subunits and not just the reassembly of pre-existing subunits after D1 replacement. In contrast, genes involved in glycogen degradation and carotenoid biosynthesis pathways were more particularly upregulated in response to LT. Altogether, these experiments allowed us to identify responses common to all stresses and those more specific to a given stress, thus highlighting genes potentially involved in niche acclimation of a key member of marine ecosystems. Our data also revealed important specific features of the stress responses compared to model freshwater cyanobacteria.
doi:10.3389/fmicb.2020.01707 pmid:32793165 pmcid:PMC7393227 fatcat:d7rxl2zicrelrdql75asw5koue

Plastid genomes of two brown algae, Ectocarpus siliculosus and Fucus vesiculosus: further insights on the evolution of red-algal derived plastids

Gildas Le Corguillé, Gareth Pearson, Marta Valente, Carla Viegas, Bernhard Gschloessl, Erwan Corre, Xavier Bailly, Akira F Peters, Claire Jubin, Benoit Vacherie, J Mark Cock, Catherine Leblanc
2009 BMC Evolutionary Biology  
Heterokont algae, together with cryptophytes, haptophytes and some alveolates, possess red-algal derived plastids. The chromalveolate hypothesis proposes that the red-algal derived plastids of all four groups have a monophyletic origin resulting from a single secondary endosymbiotic event. However, due to incongruence between nuclear and plastid phylogenies, this controversial hypothesis remains under debate. Large-scale genomic analyses have shown to be a powerful tool for phylogenetic
more » ... uction but insufficient sequence data have been available for red-algal derived plastid genomes. The chloroplast genomes of two brown algae, Ectocarpus siliculosus and Fucus vesiculosus, have been fully sequenced. These species represent two distinct orders of the Phaeophyceae, which is a major group within the heterokont lineage. The sizes of the circular plastid genomes are 139,954 and 124,986 base pairs, respectively, the size difference being due principally to the presence of longer inverted repeat and intergenic regions in E. siliculosus. Gene contents of the two plastids are similar with 139-148 protein-coding genes, 28-31 tRNA genes, and 3 ribosomal RNA genes. The two genomes also exhibit very similar rearrangements compared to other sequenced plastid genomes. The tRNA-Leu gene of E. siliculosus lacks an intron, in contrast to the F. vesiculosus and other heterokont plastid homologues, suggesting its recent loss in the Ectocarpales. Most of the brown algal plastid genes are shared with other red-algal derived plastid genomes, but a few are absent from raphidophyte or diatom plastid genomes. One of these regions is most similar to an apicomplexan nuclear sequence. The phylogenetic relationship between heterokonts, cryptophytes and haptophytes (collectively referred to as chromists) plastids was investigated using several datasets of concatenated proteins from two cyanobacterial genomes and 18 plastid genomes, including most of the available red algal and chromist plastid genomes. The phylogenetic studies using concatenated plastid proteins still do not resolve the question of the monophyly of all chromist plastids. However, these results support both the monophyly of heterokont plastids and that of cryptophyte and haptophyte plastids, in agreement with nuclear phylogenies.
doi:10.1186/1471-2148-9-253 pmid:19835607 pmcid:PMC2765969 fatcat:fvopwmbsgrcvnlbs2vct4kw5ti

Dietary aquaculture by-product hydrolysates: impact on the transcriptomic response of the intestinal mucosa of European seabass (Dicentrarchus labrax) fed low fish meal diets

Alexandre Leduc, Céline Zatylny-Gaudin, Marie Robert, Erwan Corre, Gildas Le Corguille, Hélène Castel, Antoine Lefevre-Scelles, Vincent Fournier, Enric Gisbert, Karl B. Andree, Joël Henry
2018 BMC Genomics  
The sequencing of 100-pb paired-end reads was performed on an Illumina Miseq Sequencer at the SéSAME Platform (Centre de Lutte Contre le Cancer François Baclesse, Caen, France).  ... 
doi:10.1186/s12864-018-4780-0 pmid:29793421 pmcid:PMC5968468 fatcat:dvtm2ixdf5eh5kkbirb5exd3em

Crustacean cardioactive peptides: Expression, localization, structure, and a possible involvement in regulation of egg-laying in the cuttlefish Sepia officinalis

Maxime Endress, Céline Zatylny-Gaudin, Erwan Corre, Gildas Le Corguillé, Louis Benoist, Jérôme Leprince, Benjamin Lefranc, Benoît Bernay, Alexandre Leduc, Jimmy Rangama, Anne-Gaëlle Lafont, Arnaud Bondon (+1 others)
2018 General and Comparative Endocrinology  
The peptides were characterized by MALDI-TOF mass spectrometry on a Voyager DE-PRO (AB Sciex, Les Ulis, France) in the reflector mode, with CHCA as a matrix.  ... 
doi:10.1016/j.ygcen.2017.12.009 pmid:29278693 fatcat:re6zwc6qbfajlerayjmi5ashry

Community-driven data analysis training for biology [article]

Bérénice Batut, Saskia Hiltemann, Andrea Bagnacani, Dannon Baker, Vivek Bhardwaj, Clemens Blank, Anthony Bretaudeau, Loraine Guéguen, Martin Čech, John Chilton, Dave Clements, Olivia Doppelt-Azeroual (+24 others)
2017 bioRxiv   pre-print
The primary problem with the explosion of biomedical datasets is not the data itself, not computational resources, and not the required storage space, but the general lack of trained and skilled researchers to manipulate and analyze these data. Eliminating this problem requires development of comprehensive educational resources. Here we present a community-driven framework that enables modern, interactive teaching of data analytics in life sciences and facilitates the development of training
more » ... erials. The key feature of our system is that it is not a static but a continuously improved collection of tutorials. By coupling tutorials with a web-based analysis framework, biomedical researchers can learn by performing computation themselves through a web-browser without the need to install software or search for example datasets. Our ultimate goal is to expand the breadth of training materials to include fundamental statistical and data science topics and to precipitate a complete re-engineering of undergraduate and graduate curricula in life sciences.
doi:10.1101/225680 fatcat:bbgha6r4rbhifp5zx3mdj6tt6e
« Previous Showing results 1 — 15 out of 29 results