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| Registros recuperados: 57 | |
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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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| 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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| 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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| 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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| Dupont, Samuel; Lokmer, A.; Corre, E.; Auguet, Jean-christophe; Petton, Bruno; Toulza, E.; Montagnani, Caroline; Tanguy, G.; Pecqueur, D.; Salmeron, C.; Guillou, L.; Desnues, C.; La Scola, B.; Bou Khalil, J.; De Lorgeril, Julien; Mitta, Guillaume; Gueguen, Yannick; Escoubas, Jean Michel. |
| Background The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health. Results We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a... |
| Tipo: Text |
Palavras-chave: Oyster genetic background; Hemolymph microbiota dynamics; Early-life microbiota; Trans-kingdom interactions; Crassostrea gigas; Within-host ecosystem. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73916/73254.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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| 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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| Roberts, S; Gueguen, Yannick; De Lorgeril, Julien; Goetz, F. |
| Interleukin-17 (IL-17) gene models have been found in the sequenced genomes of Strongylocentrotus purpuratus and Caenorhabditis elegans. However, there have been no published reports on the empirical cloning and characterization of any interleukin cDNAs in invertebrates. From a Pacific oyster (Crossostrea gigas) hemocyte cDNA library, two clones were obtained that encoded a protein similar to vertebrate IL-17s. The putative oyster IL-17 homolog (CgIL-17) was 27% identical to rainbow trout IL-17D, 21% to human IL-17D and 24% to an IL-17D-like gene model obtained from the annotation of the sea urchin genome. IL-17s from the oyster, sea urchin, trout and human, contained conserved cysteine residues found in all forms of IL-17 in mammals. Injection of bacteria... |
| Tipo: Text |
Palavras-chave: Invertebrate innate immunity; Crassostrea gigas; Invertebrate cytokines; Hemocytes; Pacific oyster; Interleukin. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4151.pdf |
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| Cardona, Emilie; Saulnier, Denis; Lorgeoux, Benedicte; Chim, Liet; Gueguen, Yannick. |
| This study compares the antioxidant and antimicrobial transcriptional expression of blue shrimps reared according to two different systems, BioFloc Technology (BFT) and Clear sea Water (CW) and their differential responses when facing an experimental sublethal hydrogen peroxide stress. After 30 days of rearing, juvenile shrimps were exposed to H2O2 stress at a concentration of 30 ppm during 6 hours. The oxidative stress caused by H2O2 was examined in the digestive glands of the shrimp, in which antioxidant enzyme (AOE) and antimicrobial peptide (AMP) gene expression were analysed by quantitative real-time PCR. Results showed that rearing conditions did not affect the expression of genes encoding AOEs or AMPs. However, H2O2 stress induced a differential... |
| Tipo: Text |
Palavras-chave: Biofloc; Shrimps; Antimicrobial peptides; Antioxidant enzymes. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38116/36269.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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| Gueguen, Yannick; Saulnier, Denis; Santini, Adrien; Magre, Kevin; Garen, Pierre; Bernagout, Solene; Nohl, Marine; Bouisset, Patrick; Helme, Herehia; Planes, Serge; Le Moullac, Gilles. |
| This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM,... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; French Polynesia; Cadmium; Chromium; Gene expression; Metallothionein. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48707/49146.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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| 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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| Simon-colin, Christelle; Gueguen, Yannick; Bachere, Evelyne; Kouzayha, Achraf; Saulnier, Denis; Gayet, Nicolas; Guezennec, Jean. |
| Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Exopolysaccharide; Tachyplesin; Antimicrobial. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38599/37128.pdf |
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| Gueguen, Yannick; Czorlich, Yann; Mastail, Max; Le Tohic, Bruno; Defay, Didier; Lyonnard, Pierre; Marigliano, Damien; Gauthier, Jean-pierre; Bari, Hubert; Lo, Cedrik; Chabrier, Sebastien; Le Moullac, Gilles. |
| Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Pearl rotation; Biomineralization. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38598/37127.pdf |
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| Registros recuperados: 57 | |
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