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| Registros recuperados: 76 | |
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| Offret, Clement; Paulino, Sauvann; Gauthier, Olivier; Château, Kevin; Bidault, Adeline; Corporeau, Charlotte; Miner, Philippe; Petton, Bruno; Pernet, Fabrice; Fabioux, Caroline; Paillard, Christine; Blay, Gwenaelle Le. |
| Digestive microbiota provides a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters Crassostrea gigas and clams Ruditapes philippinarum, two bivalves with different ecological niches. Based on the 16S rRNA region sequencing, digestive glands, seawater and sediments harbored specific bacterial communities, dominated by OTUs assigned to the Mycoplasmatales, Desulfobacterales and Rhodobacterales orders, respectively. Field implantation modified digestive bacterial microbiota of both bivalve species according to their intertidal position.... |
| Tipo: Text |
Palavras-chave: Microbiota; Oysters; Clams; Intertidal zone; Digestive gland; Metabarcoding. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73961/73320.pdf |
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| Pernet, Fabrice. |
| Le naissain d’huître creuse Crassostrea gigas est touché chaque année depuis 2008 par des mortalités causées par un microvariant de l’ostreid herpesvirus 1 (OsHV-1 μVar). Plusieurs études montrent que ces évènements de mortalité se produisent préférentiellement lorsque la température de l’eau est comprise entre 16°C et 24°C. Par conséquent, une exposition rapide des huîtres infectées par OsHV-1 à des températures supérieures à 24°C pourrait limiter les mortalités causées par le virus. Il est proposé de (1) vérifier l’hypothèse selon laquelle l’exposition à haute température réduit la mortalité des huîtres infectées par OsHV-1, et (2) déterminer si les animaux qui ont survécu suite à l’infection par OsHV-1 et au traitement thermique sont... |
| Tipo: Text |
Palavras-chave: Epidémiologie; Huître; OsHV-1; Risque; Survie; Température; Epidemiology; Oysters; OsHV-1; Risk; Survival; Temperature. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00434/54574/55953.pdf |
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| Seychelles, L. H.; Audet, C.; Tremblay, R.; Lemarchand, K.; Pernet, Fabrice. |
| The proliferation of bacteria in intensive aquaculture systems may be responsible for poor growth and mass mortality of marine fish larvae. Essential fatty acids provided in the diet could protect larvae by modulation of the immune response via arachidonic acid (AA) and eicosapentaenoic acid (EPA). Winter flounder Pseudopleuronectes americanus larvae were fed rotifers Brachionus plicatilis enriched with three commercial diets containing different fatty acid profiles. Bacterial colonization on the gills and skin and in the intestinal lumen was evaluated at the end of the rotifer feeding period (day 26), and growth was surveyed until metamorphosis. At 26 days post hatching, larvae fed rotifers containing the higher AA content and with a higher... |
| Tipo: Text |
Palavras-chave: Bacteria; Colonization; Fatty acids; Live feed; Winter flounder. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14273/12399.pdf |
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| Lupo, Coralie; Dutta, Bhagat Lal; Petton, Sebastien; Ezanno, P; Tourbiez, Delphine; Travers, Marie-agnes; Pernet, Fabrice; Bacher, Cedric. |
| Vibrio aestuarianus infection in oyster populations causes massive mortality, resulting in losses for oyster farmers. Such dynamics result from host-pathogen interactions and contagion through water-borne transmission. To assess the spatiotemporal spread of V. aestuarianus infection and associated oyster mortality at a bay scale, we built a mathematical model informed by experimental infection data at 2 temperatures and spatially dependent marine connectivity of oyster farms. We applied the model to a real system and tested the importance of each factor using a number of modelling scenarios. Results suggest that introducing V. aestuarianus in a fully susceptible adult oyster population in the bay would lead to the mortality of all farmed oysters over 6 to... |
| Tipo: Text |
Palavras-chave: Basic reproduction number; Crassostrea gigas; Hydrodynamics; Oyster disease; Sensitivity analysis; Vibrio aestuarianus. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77459/79114.pdf |
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| Fuhrmann, Marine; Richard, Gaëlle; Quere, Claudie; Petton, Bruno; Pernet, Fabrice. |
| Environmental change in the marine realm has been accompanied by emerging diseases as new pathogens evolve to take advantage of hosts weakened by environmental stress. Here we investigated how an exposure to reduced seawater pH influenced the response of the oyster Crassostrea gigas to an infection by the Ostreid herpesvirus type I (OsHV-1). Oysters were acclimated at pH 8.1 or pH 7.8 and then exposed to OsHV-1. Their survival was monitored and oyster tissues were sampled for biochemical analyses. The survival of oysters exposed to OsHV-1 at pH 7.8 was lower (33.5%) than that of their counterparts at pH 8.1 (44.8%) whereas levels of OsHV-1 DNA were similar. Energetic reserves, fatty acid composition and prostaglandin levels in oyster did not vary... |
| Tipo: Text |
Palavras-chave: Acidification; Bivalve; Disease; Environment; Metabolism; Mortality risk. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58334/60887.pdf |
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| Genard, Bertrand; Moraga, Dario; Pernet, Fabrice; David, Elise; Boudry, Pierre; Tremblay, Rejean. |
| Quantification of mRNA of genes related to metabolism, immunity and cellular stress was examined in relation to a massive mortality event during the culture of American oyster larvae, Crassostrea virginica which was probably, in regard to previous microbiological analysis, induced by vibrio infection. To document molecular changes associated with the mortality event, mRNA levels were compared to biochemical and physiological data, previously described in a companion paper. Among the 18 genes studied, comparatively to the antibiotic control, 10 showed a lower relative gene expression when the massive mortality occurred. Six of them are presumed to be related to metabolism, corroborating the metabolic depression associated with the mortality event suggested... |
| Tipo: Text |
Palavras-chave: Massive mortality; Relative gene expression; Metabolism; Immunity; Cellular stress; Larvae. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00075/18585/16138.pdf |
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| Fuhrmann, Marine; Delisle, Lizenn; Petton, Bruno; Corporeau, Charlotte; Pernet, Fabrice. |
| The Pacific oyster, Crassostrea gigas, is an osmoconforming bivalve exposed to wide salinity fluctuations. The physiological mechanisms used by oysters to cope with salinity stress are energy demanding and may impair other processes, such as defense against pathogens. This oyster species has been experiencing recurrent mortality events caused by the Ostreid herpesvirus 1 (OsHV-1). The objectives of this study were to investigate the effect of salinity (10, 15, 25 and 35‰) on energetic reserves, key enzyme activities and membrane fatty acids, and to identify the metabolic risk factors related to OsHV-1-induced mortality of oysters. Acclimation to low salinity led to increased water content, protein level, and energetic reserves (carbohydrates and... |
| Tipo: Text |
Palavras-chave: Bivalve; Disease; Environment; Metabolism; Mortality risk; Salinity. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00427/53886/54958.pdf |
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| Chouvelon, Tiphaine; Schaal, G.; Grall, J.; Pernet, Fabrice; Perdriau, M.; A-pernet, E. J.; Le Bris, H.. |
| Anthropogenic activities and land-based inputs into the sea may influence the trophic structure and functioning of coastal and continental shelf ecosystems, despite the numerous opportunities and services the latter offer to humans and wildlife. In addition, hydrological structures and physical dynamics potentially influence the sources of organic matter (e.g., terrestrial versus marine, or fresh material versus detrital material) entering marine food webs. Understanding the significance of the processes that influence marine food webs and ecosystems (e.g., terrestrial inputs, physical dynamics) is crucially important because trophic dynamics are a vital part of ecosystem integrity. This can be achieved by identifying organic matter sources that enter food... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38612/37468.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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| Richard, Gaelle; Guerard, Fabienne; Corporeau, Charlotte; Lambert, Christophe; Paillard, Christine; Pernet, Fabrice. |
| We investigated the effect of brown ring disease (BRD)1 development and algal diet on energy reserves and activity of enzymes related to energy metabolism, antioxidant system and immunity in Manila clam, Ruditapes philippinarum. We found that algal diet did not impact the metabolic response of clams exposed to Vibrio tapetis. At two days post-injection (dpi), activities of superoxide dismutase and glutathione peroxidase (GPx) decreased whereas activities of nitric oxide synthase (iNOS) and catalase increased in infected clams, although no clinical signs were visible (BRD-). At 7 dpi, activities of several antioxidant and immune-related enzymes were markedly increased in BRD-likely indicating an efficient reactive oxygen species (ROS) scavenging compared to... |
| Tipo: Text |
Palavras-chave: Antioxidant enzymes; Immunity; Energetic metabolism; Ruditapes philippinarum; Vibrio tapetis. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00316/42684/42057.pdf |
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| Delisle, Lizenn; Fuhrmann, Marine; Quere, Claudie; Pauletto, Marianna; Pichereau, Vianney; Pernet, Fabrice; Corporeau, Charlotte. |
| Voltage-dependent anion channel (VDAC) is a key mitochondrial protein. VDAC drives cellular energy metabolism by controlling the influx and efflux of metabolites and ions through the mitochondrial membrane, playing a role in its permeabilization. This protein exerts a pivotal role during the white spot syndrome virus (WSSV) infection in shrimp, through its involvement in a particular metabolism that plays in favor of the virus, the Warburg effect. The Warburg effect corresponds to an atypical metabolic shift toward an aerobic glycolysis that provides energy for rapid cell division and resistance to apoptosis. In the Pacific oyster Crassostrea gigas, the Warburg effect occurs during infection by Ostreid herpesvirus (OsHV-1). At present, the role of VDAC in... |
| Tipo: Text |
Palavras-chave: Voltage-dependent anion channel; Warburg effect; Crassostrea gigas; Ostreid herpes virus. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00420/53129/54142.pdf |
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| Genard, Bertrand; Pernet, Fabrice; Lemarchand, Karine; Boudry, Pierre; Moraga, Dario; Tremblay, Rejean. |
| In this paper, biochemical and physiological analyses were used to characterize changes associated with mortality event occurred during veliger development of American oyster, Crassostrea virginica. Biochemical analyses included the evaluation of lipid classes, fatty acid composition and total protein content. Larval physiology was evaluated by studying feeding activity, enzymes related to energy metabolism, oxidative stress levels and enzymatic antioxidant defenses. These analyses were complemented by bacterial community analyses as well as by measuring larval oyster performance. We observed that mortality events coincided with (1) strong changes in the surrounding bacterial community; (2) a progressive decrease in feeding activity; (3) higher levels of... |
| Tipo: Text |
Palavras-chave: Massive mortality; Larvae; Microbial environment; Lipid; Fatty acids; Energy metabolism; Oxidative stress; Antioxidant enzymes; Crassostrea virginica. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00051/16231/13753.pdf |
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| Pernet, Fabrice; Malet, Nathalie; Pastoureaud, Annie; Vaquer, Andre; Quere, Claudie; Dubroca, Laurent. |
| Carbon stable isotopes and fatty acids were measured in the suspended particulate organic matter (POM) of the Thau lagoon to study its qualitative temporal changes in relation to environmental factors and to identify the food sources of bivalves over a one-yr-cycle in relation to their growth. Reciprocally, the impact of shellfish farming on POM was also studied. Oysters and mussels were sampled and measured for biometry, stable isotopes and fatty acid composition. Water samples were collected at two sites, both inside and outside of the shellfish farming area, to determine concentrations in POM, chlorophyll a (Chl a) and stable isotopes. Carbon isotopes and fatty acids in bivalves reflected seasonal changes in food sources, which varied consistently with... |
| Tipo: Text |
Palavras-chave: Aquaculture; Bivalve; Competition; Feeding ecology; Growth; Trophic markers. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00075/18575/16177.pdf |
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| Rayssac, Nathalie; Malet, Nathalie; Pernet, Fabrice. |
| The objective of this work is to understand why oysters Crassostrea gigas shows low settlement success in the Thau lagoon despite the fact that biomass of adults is elevated and that larvae show normal development in the water column. Our hypotheses are that oysters compete for food or space with other filter-feeders animals such as sponges, ascidians and other bivalves. To test the trophic hypothesis, we analysed the entire settler community harvested on four-month-old collectors deployed in the Thau lagoon during the summer 2009 for stable isotopes and fatty acids. Based on the isotopic, crustacean amphipods and barnacles can be rejected as a potential food competitor of juvenile oysters. However, other bivalves such as Mytilus sp., Anomia sp., and... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12665/9555.pdf |
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| Soletchnik, Patrick; Mazurie, Joseph; Allain, Gwenhael; Bedier, Edouard; Benabdelmouna, Abdellah; Blin, Jean-louis; Bouquet, Anne-lise; Cochet, Hélène; Degremont, Lionel; Gaussem, Florian; Gervasoni, Erika; Glize, Philippe; Petton, Bruno; Roussel, Pierre-yves; Pernet, Fabrice. |
| This paper summarizes knowledge about relations between husbandry practices and oyster spat mortalities since 2008 in France. These relations are strictly analyzed from a panel of experiments set on the shore (in outdoor experiments) by Ifremer teams and technical institutes all over French coasts. Results show some practices are able to reduce spat mortality with some influencing factors relevant of spat quality (sanitary status, natural or genetic selection) or husbandry practices. Spat “free” of virus is able to survive up to 90% when it is isolated and confined in ponds or nursery, during an epidemic crisis. When outbreaks occurred in oyster beds, natural or nursery spat died in almost same proportions. In 2010, some studies conducted in Mediterranean... |
| Tipo: Text |
Palavras-chave: Surmortalité; Naissain; Huître creuse; OsHV-1; Pratiques culturales; Mortality; Spat; Cupped oyster; Crassostrea gigas; OsHV-1; Cultural practices. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00032/14280/25847.pdf |
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| Registros recuperados: 76 | |
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