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| Registros recuperados: 57 | |
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| Gueguen, Yannick; Romestand, Bernard; Fievet, Julie; Schmitt, Paulina; Destoumieux Garzon, Delphine; Franck, Vandenbulcke; Philippe, Bulet; Bachere, Evelyne. |
| A cDNA sequence that encodes a 61-amino acid polypeptide precursor with homologies to proline-rich antimicrobial peptides (AMPs) was identified in the oyster Crassostrea gigas. After release of a hydrophobic signal peptide. the resulting 37-amino acid peptide, Cg-Prp, is composed of an acidic region and a cationic proline-rich region. To evaluate the biological properties of Cg-Prp, multiple proline-rich peptides corresponding to putative processing of the full-length Cg-Prp were synthesized. A limited antimicrobial activity was observed for two of them, which also showed strong synergistic antimicrobial activity with Cg-Def, a defensin from C gigas. To our knowledge, this is the first evidence of synergy between a defensin and another AMP in an... |
| Tipo: Text |
Palavras-chave: Antimicrobial peptide; Mollusk; Synergy; Invertebrate; Innate immunity; Pacific oyster. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6232.pdf |
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| Joubert, Caroline; Linard, Clementine; Le Moullac, Gilles; Soyez, Claude; Saulnier, Denis; Teaniniuraitemoana, Vaihiti; Ky, Chin-long; Gueguen, Yannick. |
| In this study, we analyzed the combined effect of microalgal concentration and temperature on the shell growth of the bivalve Pinctada margaritifera and the molecular mechanisms underlying this biomineralization process. Shell growth was measured after two months of rearing in experimental conditions, using calcein staining of the calcified structures. Molecular mechanisms were studied though the expression of 11 genes encoding proteins implicated in the biomineralization process, which was assessed in the mantle. We showed that shell growth is influenced by both microalgal concentration and temperature, and that these environmental factors also regulate the expression of most of the genes studied. Gene expression measurement of shell matrix protein... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00210/32095/30535.pdf |
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| Le Moullac, Gilles; Soyez, Claude; Latchere, Oihana; Vidal-dupiol, Jeremie; Fremery, Juliette; Saulnier, Denis; Lo Yat, Alain; Belliard, Corinne; Mazouni-gaertner, Nabila; Gueguen, Yannick. |
| The pearl culture is one of the most lucrative aquacultures worldwide. In many South Pacific areas, it depends on the exploitation of the pearl oyster Pinctada margaritifera and relies entirely on the environmental conditions encountered in the lagoon. In this context, assessing the impact of climatic stressors, such as global warming and ocean acidification, on the functionality of the resource in terms of renewal and exploitation is fundamental. In this study, we experimentally addressed the impact of temperature (22, 26, 30 and 34 °C) and partial pressure of carbon dioxide pCO2 (294, 763 and 2485 μatm) on the biomineralization and metabolic capabilities of pearl oysters. While the energy metabolism was strongly dependent on temperature, results showed... |
| Tipo: Text |
Palavras-chave: Global change; Pearl oyster; Bioenergetic; Biomineralization; Pacific ocean; French Polynesia. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00332/44364/43969.pdf |
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| Teaniniuraitemoana, Vaihiti; Lepretre, Maxime; Levy, Peva; Vanaa, Vincent; Parrad, Sophie; Gaertner-mazouni, Nabila; Gueguen, Yannick; Huvet, Arnaud; Le Moullac, Gilles. |
| The black-lip pearl oyster Pinctada margaritifera is a protandrous hermaphrodite species. Its economic value has led to the development of controlled hatchery reproduction techniques, although many aspects remain to be optimized. In order to understand reproductive mechanisms and their controlling factors, two independent experiments were designed to test hypotheses of gametogenesis and sex ratio control by environmental and hormonal factors. In one, pearl oysters were exposed under controlled conditions at different combinations of temperature (24 and 28°C) and food level (10,000 and 40,000 cells mL−1); whereas in the other, pearl oysters were conditioned under natural conditions into the lagoon and subjected to successive 17β-estradiol injections (100 μg... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00285/39638/38184.pdf |
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| Joubert, Caroline; Piquemal, David; Marie, Benjamin; Manchon, Laurent; Pierrat, Fabien; Zanella-cleon, Isabelle; Cochennec-laureau, Nathalie; Gueguen, Yannick; Montagnani, Caroline. |
| Background: The shell of the pearl-producing bivalve Pinctada margaritifera is composed of an organic cell-free matrix that plays a key role in the dynamic process of biologically-controlled biomineralization. In order to increase genomic resources and identify shell matrix proteins implicated in biomineralization in P. margaritifera, high-throughput Expressed Sequence Tag (EST) pyrosequencing was undertaken on the calcifying mantle, combined with a proteomic analysis of the shell. Results: We report the functional analysis of 276 738 sequences, leading to the constitution of an unprecedented catalog of 82 P. margaritifera biomineralization-related mantle protein sequences. Components of the current "chitin-silk fibroin gel-acidic macromolecule" model of... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00020/13154/10202.pdf |
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| Yang, Yinshan; Boze, Helene; Chemardin, Patrick; Padilla, Andre; Moulin, Guy; Tassanakajon, Anchalee; Pugniere, Martine; Roquet, Francoise; Destoumieux Garzon, Delphine; Gueguen, Yannick; Bachere, Evelyne; Aumelas, Andre. |
| The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and N-15 uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C-34-C-55 disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM(R)-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM(R)-174 complexes indicated rather high molecular sized aggregates, which... |
| Tipo: Text |
Palavras-chave: Ultracentrifugation; Surface plasmon resonance; Septic shock; Structure; NMR; Lipid A; Lipopolysaccharide; Anti lipopolysaccharide factor. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6320.pdf |
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| Gonzalez, Marcelo; Gueguen, Yannick; Destoumieux Garzon, Delphine; Romestand, Bernard; Fievet, Julie; Pugniere, M; Roquet, F; Escoubas, Jean-michel; Vandenbulcke, F; Levy, O; Saune, Laure; Bulet, P; Bachere, Evelyne. |
| A cDNA sequence with homologies to members of the LPS-binding protein and bactericidal/permeability-increasing protein (BPI) family was identified in the oyster Crassostrea gigas. The recombinant protein was found to bind LIPS, to display bactericidal activity against Escherichia coli, and to increase the permeability of the bacterial cytoplasmic membrane. This indicated that it is a BPI rather than an LPS-binding protein. By in situ hybridization, the expression of the C gigas BPI (Cg-bpi) was found to be induced in hemocytes after oyster bacterial challenge and to be constitutive in various epithelia of unchallenged oysters. Thus, Cg-bpi transcripts were detected in the epithelial cells of tissues/organs in contact with the external environment (mantle,... |
| Tipo: Text |
Palavras-chave: Oyster innate immunity; Mollusk; Hemocyte; Epithelia; Antimicrobial. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3564.pdf |
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| Teaniniuraitemoana, Vaihiti; Huvet, Arnaud; Levy, Peva; Gaertner-mazouni, Nabila; Gueguen, Yannick; Le Moullac, Gilles. |
| The genomics of economically important marine bivalves is studied to provide better understanding of the molecular mechanisms underlying their different reproductive strategies. The recently available gonad transcriptome of the black-lip pearl oyster Pinctada margaritifera is a novel and powerful resource to study these mechanisms in marine mollusks displaying hermaphroditic features. In this study, RNAseq quantification data of the P. margaritifera gonad transcriptome were analyzed to identify candidate genes in histologically-characterized gonad samples to provide molecular signatures of the female and male sexual pathway in this pearl oyster. Based on the RNAseq data set, stringent expression analysis identified 1,937 contigs that were differentially... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00256/36768/35374.pdf |
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| Le Moullac, Gilles; Soyez, Claude; Lyonnard, Pierre; Chabrier, Sébastien; Milhade, Leo; Gueguen, Yannick; Beliaeff, Benoit. |
| Non‐invasive functional exploration techniques can provide information on different aspects of general organism functioning and, unlike lethal or invasive techniques, allow individual organisms to be monitored for as long as necessary. For bivalves, a fairly wide variety of methods and instrumental means exist allowing physiology to be assessed on‐line while keeping animals alive and intact. The current range of non‐invasive techniques for bivalves consists of systems for measuring metabolic flows and valve activity, which can be used on bivalve molluscs for as long as an individual animal's characteristics (e.g. size) make this technically feasible. In this paper, we present some of these non‐invasive techniques with applications for pearl oyster and list... |
| Tipo: Text |
Palavras-chave: Bivalve; Filtration; Pearl rotation; Respiration; Valvometry. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71161/69551.pdf |
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| Rosa, Rafael Diego; Vergnes, Agnes; De Lorgeril, Julien; Goncalves, Priscila; Perazzolo, Luciane Maria; Saune, Laure; Romestand, Bernard; Fievet, Julie; Gueguen, Yannick; Bachere, Evelyne; Destoumieux-garzon, Delphine. |
| Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded beta-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27077/25236.pdf |
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| Gueguen, Yannick; Garnier, Julien; Robert, Lorenne; Lefranc, Marie-paule; Mougenot, Isabelle; De Lorgeril, Julien; Janech, Michael; Gross, Paul S.; Warr, Gregory W.; Cuthbertson, Brandon; Barracco, Margherita A.; Bulet, Philippe; Aumelas, André; Yang, Yinshan; Bo, Dong; Xiang, Jianhai; Tassanakajon, Anchalee; Piquemal, Piquemal; Bachere, Evelyne. |
| Antimicrobial peptides play a major role in innate immunity. The penaeidins, initially characterized from the shrimp Litopenaeus vannamei, are a family of antimicrobial peptides that appear to be expressed in all penaeid shrimps. As of recent, a large number of penaeid nucleotide sequences have been identified from a variety of penaeid shrimp species and these sequences currently reside in several databases under unique identifiers with no nomenclatural continuity. To facilitate research in this field and avoid potential confusion due to a diverse number of nomenclatural designations, we have made a systematic effort to collect, analyse, and classify all the penaeidin sequences available in every database. We have identified a common penaeidin signature... |
| Tipo: Text |
Palavras-chave: Nomenclature; Sequence database; Crustacea; Antimicrobial peptide; Penaeid shrimp; Penaeidin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2332.pdf |
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| De Lorgeril, Julien; Petton, Bruno; Lucasson, Aude; Perez, Valérie; Stenger, Pierre-louis; Degremont, Lionel; Montagnani, Caroline; Escoubas, Jean Michel; Haffner, Philippe; Allienne, Jean-françois; Leroy, Marc; Lagarde, Franck; Vidal Dupiol, Jeremie; Gueguen, Yannick; Mitta, Guillaume. |
| Background: As a major threat to the oyster industry, Pacific Oyster Mortality Syndrome (POMS) is a polymicrobial disease affecting the main oyster species farmed across the world. POMS affects oyster juveniles and became panzootic this last decade, but POMS resistance in some oyster genotypes has emerged. While we know some genetic loci associated with resistance, the underlying mechanisms remained uncharacterized. So, we developed a comparative transcriptomic approach using basal gene expression profiles between different oyster biparental families with contrasted phenotypes when confronted to POMS (resistant or susceptible). Results: We showed that POMS resistant oysters show differential expression of genes involved in stress responses, protein... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Oyster disease; Resistance; OsHV-1; Antiviral molecular pathways; Invertebrate immunity. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00602/71369/69811.pdf |
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| Lafont, Maxime; Vergnes, Agnes; Vidal-dupiol, Jeremie; De Lorgeril, Julien; Gueguen, Yannick; Haffner, Philippe; Petton, Bruno; Chaparro, Cristian; Barrachina, Celia; Destoumieux-garzon, Delphine; Mitta, Guillaume; Gourbal, Benjamin; Montagnani, Caroline. |
| Over the last decade, innate immune priming has been evidenced in many invertebrate phyla. If mechanistic models have been proposed, molecular studies aiming to substantiate these models have remained scarce. We reveal here the transcriptional signature associated with immune priming in the oyster Crassostrea gigas. Oysters were fully protected against Ostreid herpesvirus 1 (OsHV-1), a major oyster pathogen, after priming with poly(I·C), which mimics viral double-stranded RNA. Global analysis through RNA sequencing of oyster and viral genes after immune priming and viral infection revealed that poly(I·C) induces a strong antiviral response that impairs OsHV-1 replication. Protection is based on a sustained upregulation of immune genes, notably genes... |
| Tipo: Text |
Palavras-chave: Innate immunity; Priming; OsHV-1; Antiviral response; Immune memory; Oyster; POMS; Poly(I·C); Interferon; Transcriptomic. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72580/71541.pdf |
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| Maamaatuaiahutapu, Moana; Joufoques, Vaiana; Tamata, Thiery; Dupieux, Sylvain; Teissier, Alexandre; Rarahu, David; Remoissenet, Georges; Gasset, Eric; Knockaert, Camille; Gueguen, Yannick; Coves, Denis. |
| Ce rapport traite de la poursuite de l’acquisition de connaissances, du début du transfert vers le secteur privé et des futurs travaux sur de l’élevage du Paraha peue (Platax orbicularis). Acquisition de connaissances porte sur (i) Grossissement en cages en fonction du site d’élevage, tests de produits immuno-stimulants, définition de traitements anti-parasitaires, mise au point des méthodes de transport d’alevins et la mise en cages précoces d’animaux de 1 g pour le transport par voie aérienne vers les îles (i.i.) Synchronisation des pontes et mise en place d’un plan de croisement de géniteurs diminuant le risque de consanguinité et permettant un progrès génétique par la domestication et/ou la sélection, ainsi que la mise au point d’outils de... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00128/23887/21820.pdf |
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| Henneke, Ghislaine; Gueguen, Yannick; Flament, Didier; Azam, Philippe; Querellou, Joel; Dietrich, Jacques; Hubscher, Ulrich; Raffin, Jean-paul. |
| The molecular organization of the replication complex in archaea is similar to that in eukaryotes. Only two proteins homologous to subunits of eukaryotic replication factor C (RFC) have been detected in Pyrococcus abyssi (Pab). The genes encoding these two proteins are arranged in tandem. We cloned these two genes and co-expressed the corresponding recombinant proteins in Escherichia coli. Two inteins present in the gene encoding the small subunit (Pab RFC-small) were removed during cloning. The recombinant protein complex was purified by anion-exchange and hydroxyapatite chromatography. Also, the Pab RFC-small subunit could be purified, while the large subunit (Pab RFC-large) alone was completely insoluble. The highly purified Pab RFC complex possessed an... |
| Tipo: Text |
Palavras-chave: PCNA binding domain; Pyrococcus abyssi; Hyperthermophile; Archaea; Replication factor C. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/2002/publication-675.pdf |
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| Registros recuperados: 57 | |
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