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| Registros recuperados: 57 | |
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| Gueguen, Yannick; Gaertner-mazouni, Nabila; Lo, Cedrik; Le Moullac, Gilles. |
| The paper presents a state of the art on knowledge of the black pearl oyster aquaculture at the scale of French Polynesia. It also introduces the main results obtained throughout the multi-partners POLYPERL project. The goal of this project was to develop an integrated and participative action-research of the pearl oyster culture system, focusing on the environmental, technological, economical and societal dimensions impacting the industry. The research proposed ranges from the understanding of biological phenomena of the production system to socio-economic aspects and governance of the industry, taking into account the management of anthropogenic, climate and health risks. We introduce here the different papers from the POLYPERL project that are compiled... |
| Tipo: Text |
Palavras-chave: Pearl culture; Global change; French Polynesia; Pinctada margaritifera. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45698/45320.pdf |
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| Delmotte, Jean; Chaparro, Cristian; Galinier, Richard; De Lorgeril, Julien; Petton, Bruno; Stenger, Pierre-louis; Vidal-dupiol, Jeremie; Destoumieux-garzon, Delphine; Gueguen, Yannick; Montagnani, Caroline; Escoubas, Jean Michel; Mitta, Guillaume. |
| Juvenile Pacific oysters (Crassostrea gigas) are subjected to recurrent episodes of mass mortalities that constitute a threat for the oyster industry. This mortality syndrome named “Pacific Oyster Mortality Syndrome” (POMS) is a polymicrobial disease whose pathogenesis is initiated by a primary infection by a variant of an Ostreid herpes virus named OsHV-1 μVar. The characterization of the OsHV-1 genome during different disease outbreaks occurring in different geographic areas has revealed the existence of a genomic diversity for OsHV-1 μVar. However, the biological significance of this diversity is still poorly understood. To go further in understanding the consequences of OsHV-1 diversity on POMS, we challenged five biparental families of oysters to two... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Herpesvirus diversity; Genotype-genotype interactions; Oyster genetic background; Viral populations. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75533/76414.pdf |
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| Lacoste, Elise; Le Moullac, Gilles; Levy, Peva; Gueguen, Yannick; Gaertner-mazouni, Nabila. |
| In bivalve aquaculture, dominant fouling organisms are filter feeders which can compete for food with reared bivalves, sometimes causing mortality or reducing their growth rate. This study investigated the effect of biofouling on the farmed pearl oyster Pinctada margaritifera in two lagoons of French Polynesia. Survival, growth and reproduction of 2 year-old pearl oysters were monitored with regular sampling schedules, from the initial stage of colonization up to 20 months of biofouling accumulation. Control groups of pearl oysters were kept free of biofouling as is the current practice in pearl farms. After more than a year of monitoring, no significant difference was recorded in shell growth rate between pearl oysters reared with epibionts and the... |
| Tipo: Text |
Palavras-chave: Pearl oyster culture; Pinctada margaritifera; Biofouling; Growth; Reproduction. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31188/29587.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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| Latchere, Oihana; Fievet, Julie; Lo, Cedrik; Schneider, Denis; Dieu, Stephanie; Cabral, Philippe; Belliard, Corinne; Ky, Chin-long; Gueguen, Yannick; Saulnier, Denis. |
| The present study investigated the effect of electrolysis on the biomineralization capacities of juveniles of the mollusk Pinctada margaritifera for the first time. Size-selected individuals from two groups, “Medium” and “Large”, from a multi-parental family produced in a hatchery system were subjected to electrolysis under a low voltage current over a nine-week experimental period. The growth of the juveniles was individually monitored and assessed weekly by wet weight and shell height measurements. At the end of the experiment, mantle tissue was sampled for biomineralization-related gene expression analysis. Electrolysis significantly increased pearl oyster growth in terms of shell height and wet weight for Large juveniles from the 5th and the 2nd week,... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Pinctada margaritifera; Electrolysis; Biomineralization; Gene expression. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00343/45410/44924.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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| Zappa, Sebastien; Rolland, Jean-luc; Flament, Didier; Gueguen, Yannick; Boudrant, Joseph; Dietrich, Jacques. |
| This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of the E. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70 degreesC, respectively. Thus far, P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105 degreesC of 18 and 5 h, respectively.... |
| Tipo: Text |
Palavras-chave: Escherichia coli; Characterization; Isolation; Gene; Alkaline phosphatase; Pyrococcus abyssi; Archaeon. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1268.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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| 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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| Le Moullac, Gilles; Soyez, Claude; Vidal-dupiol, Jeremie; Belliard, Corinne; Fievet, Julie; Sham-koua, Manaarii; Lo-yat, Alain; Saulnier, Denis; Gaertner-mazouni, N.; Gueguen, Yannick. |
| The possible consequences of acidification on pearl farming are disruption of oyster metabolism and change in growth. In the laboratory, we studied the impact of pCO2 (3540, 1338 and 541μatm) on the physiology of pearl oysters exposed for 100 days. This experiment was repeated after an interval of one year. Several physiological compartments were examined in pearl oysters: the scope for growth by measuring ingestion, assimilation and oxygen consumption, gametogenesis by means of histological observations, shell growth by measurement and observation by optical and electronic microscopy, and at molecular level by measuring the expression of nine genes of mantle cells implied in the biomineralisation process. Results from both experiments showed that high... |
| Tipo: Text |
Palavras-chave: Global change; Pearl oyster; Bioenergetic; Biomineralization; Pacific Ocean; French Polynesia. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00321/43189/42737.pdf |
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| De Lorgeril, Julien; Escoubas, Jean Michel; Loubiere, Vincent; Pernet, Fabrice; Le Gall, Patrik; Vergnes, Agnes; Aujoulat, Fabien; Jeannot, Jean-luc; Jumas-bilak, Estelle; Got, Patrice; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne. |
| Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We... |
| Tipo: Text |
Palavras-chave: Host pathogen interaction; Innate immunity; Invertebrate; Mollusk; In situ mortality; Total bacteria; Crassostrea gigas. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00433/54470/55845.pdf |
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| Thomas, Yoann; Belliard, Corinne; Garen, Pierre; Gueguen, Yannick; Montagnani, Caroline. |
| In French Polynesia, the black-lip pearl oyster Pinctada margaritifera has been farmed to produce pearls since the 1980s, forming the basis of a major industry. The sustainability of this activity relies on spat collection in the lagoons. However, pearl oyster spat can be difficult to identify for the evaluation of stock variations. It is especially hard to distinguish Pinctada spp. larvae at a very early stage of development. In the present study, a whole- mount in situ hybridisation (ISH) technique was developed to allow the discrimination of larvae of closely-related pearl oyster species found in the French Polynesian atolls. Using specific ribosomal 16S-DNA sequence data, we were able to successfully differentiate between Pinctada margaritifera and... |
| Tipo: Text |
Palavras-chave: Whole larvae in situ hybridisation; 16S rRNA; Plankton; Species identification; Pearl oyster; Pinctada margaritifera. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14603/11923.pdf |
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| Rouze, Heloise; Lecellier, Gael J.; Saulnier, Denis; Planes, Serge; Gueguen, Yannick; Wirshing, Herman H.; Berteaux-lecellier, Veronique. |
| The adaptative bleaching hypothesis (ABH) states that, depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to “switch” or “shuffle” their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community and, thus, contribute to the coral’s overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional molecular methods, to assess the presence of... |
| Tipo: Text |
Palavras-chave: Corals; French polynesia; Clade B; Symbiodinium; QPCR; Flexibility; Generalist; Faithful clade. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00365/47652/47683.pdf |
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| Chim, Liet; Cardona, Emilie; Lorgeoux, Benedicte; Gueguen, Yannick; Saulnier, Denis; Goguenheim, Jean; Wantiez, Laurent; Cahu, Chantal. |
| Shrimp farming in New-Caledonia faces up to difficulties. A fluctuating quality of broodstock prevents sustainable production of larvae in quantity and quality. The traditional extensive rearing method of broodstock in outdoor earthen ponds used in New Caledonia raises several issues: poor water quality control and biosecurity. Therefore it is fundamental to modify the broodstock culture strategy in order to achieve an easier water quality management and maximal biosecurity. Biofloc technology (BFT) offers easier water quality management, higher natural productivity, higher level of biosecurity, and could be a good alternative. Since 2011 a R&D program started under the supervision of IFREMER in New Caledonia and French Polynesia in order to study and... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00250/36084/34635.pdf |
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| Schmitt, Paulina; Gueguen, Yannick; Desmarais, Erick; Bachere, Evelyne; De Lorgeril, Julien. |
| Background: To gain insight into the molecular diversity of antimicrobial peptides and proteins in the oyster Crassostrea gigas, we characterized and compared the sequence polymorphism of the antimicrobial peptides (AMPs), Cg-Defensins (Cg-Defs) and Cg-Proline Rich peptide (Cg-Prp), and of the bactericidal permeability increasing protein, Cg-BPI. For that, we analyzed genomic and transcript sequences obtained by specific PCR amplification and in silico searches. Results: High diversification among the three antimicrobial effectors was evidenced by this polymorphism survey. On the basis of sequence phylogenies, each AMP aggregates into clearly defined groups of variants and is the product of a multigenic family displaying a variety of gene structures. In... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11182/6691.pdf |
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| Marie, Benjamin; Joubert, Caroline; Tayale, Alexandre; Zanella-cleon, Isabelle; Belliard, Corinne; Piquemal, David; Cochennec-laureau, Nathalie; Marin, Frederic; Gueguen, Yannick; Montagnani, Caroline. |
| Mollusca evolutionary success can be attributed partly to their efficiency to sustain and protect their soft body with an external biomineralized structure, the shell. Current knowledge of the protein set responsible for the formation of the shell microstructural polymorphism and unique properties remains largely patchy. In Pinctada margaritifera and Pinctada maxima, we identified 80 shell matrix proteins, among which 66 are entirely unique. This is the only description of the whole "biomineralization toolkit" of the matrices that, at least in part, is thought to regulate the formation of the prismatic and nacreous shell layers in the pearl oysters. We unambiguously demonstrate that prisms and nacre are assembled from very different protein repertoires.... |
| Tipo: Text |
Palavras-chave: Mantle; Mollusk shell matrix proteins; Proteome; Transcriptome; Evolution. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00118/22959/20922.pdf |
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| Registros recuperados: 57 | |
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