|
|
|
| Registros recuperados: 65 | |
|
|
| Delaporte, Maryse; Soudant, Philippe; Moal, Jeanne; Giudicelli, Emilie; Lambert, Christophe; Seguineau, Catherine; Samain, Jean-francois. |
| Arachidonic acid (20:4n-6, ArA) and its eicosanoid metabolites have been demonstrated to be implicated in immune functions of vertebrates, fish, and insects. Thus, the aim of this study was to assess the impact of ArA supplementation on the FA composition and hemocyte parameters of oysters Crassostrea gigas. Oyster dietary conditioning consisted of direct addition of ArA solutions at a dose of 0, 0.25, or 0.41 mu g ArA per mL of seawater into tanks in the presence or absence of T-Iso algae. Results showed significant incorporation of ArA into gill polar lipids when administered with algae (up to 19.7%) or without algae (up to 12.1%). ArA supplementation led to an increase in hemocyte numbers, phagocytosis, and production of reactive oxygen species by... |
| Tipo: Text |
Palavras-chave: Hemocyte parameters; Oyster immunity; Arachidonic Acid; Poly unsaturated fatty acids; Nutrition; Bivalve; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1876.pdf |
| |
|
| |
|
|
| Degremont, Lionel; Boudry, Pierre; Ropert, Michel; Samain, Jean-francois; Bedier, Edouard; Soletchnik, Patrick. |
| This study investigated the effects of age (first or second summer of life) and environment (three study sites on French coasts) on summer mortality in Crassostrea gigas, using three generations of oysters produced during the Morest project. For each generation, two groups of oysters, selected either as 'resistant' (R) or 'susceptible' (S) to summer mortality at the age of 6 months in Rivière d'Auray (RA, South Brittany), were evaluated. In Ronce (Marennes-Oléron Bay) and RA, R oysters had low mortality during their first and second summers, while mortality was higher during the second summer in Baie des Veys (BDV, Normandy). In RA, S oysters exhibited higher mortality during their first summer than during their second, while the opposite result was found... |
| Tipo: Text |
Palavras-chave: Summer mortality; Age; Environment; Genetic; Crassostrea gigas. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6972.pdf |
| |
|
|
| Tremblay, Rejean; Cartier, Simon; Miner, Philippe; Pernet, Fabrice; Quere, Claudie; Moal, Jeanne; Muzellec, Marie-louise; Mazuret, Michel; Samain, Jean-francois. |
| The main objective of this study was to identify algal diets that maximize the survival and growth and alter the biochemical content of Pecten maximus larvae with the aim of improving metamorphosis. We also evaluated the potential of the cryptophyceae Rhodomonas salina as a food source for these larvae. Two flagellates, Isochrysis aff. galbana (T) and Pavlova lutheri (P), and two diatoms, Chaetoceros gracilis (C) or Skeletonema costatum (S), were tested as two ternary diets, namely PTC and PTS. PTC and PTS were compared with diets that also included R. salina (R). The addition of R. salina and the replacement of C. gracilis by S. costatum in the traditional hatchery diet seem to be two interesting alternatives for increasing the productivity of larval... |
| Tipo: Text |
Palavras-chave: Algal fatty acids and sterols; Energetic content; Metamorphosis; Nutrition; Scallop. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2404.pdf |
| |
|
| |
|
| |
|
| |
|
|
| Lambert, C.; Moal, J.; Pouvreau, Stephane; Le Moullac, Gilles; Samain, Jean-francois. |
| Les mortalités apparaissent toujours très rapidement après le passage de la température de l'eau à 19°C. II a bien été montré que ce n'était pas la valeur absolue de la température qui était associée à la mortalité, puisque des années très chaudes comme 2003, peu de mortalités étaient enregistrées. II s'agit plutôt d'un seuil à partir duquel le risque devient réel. La température affecte tous les processus de la physiologie et c'est un facteur clef de la distribution géographique des espèces. Les espèces se maintiennent dans les conditions environnementales qui ont permis leur adaptation. Les mortalités traduisent donc une rupture de l'adaptation ou une modification brutale de l'environnement qui peut affecter les équilibres qui se sont installés entre... |
| Tipo: Text |
|
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41537/40745.pdf |
| |
|
|
| Lambert, Christophe; Soudant, Phillippe; Degremont, Lionel; Delaporte, Maryse; Moal, Jeanne; Boudry, Pierre; Jean, Frédéric; Huvet, Arnaud; Samain, Jean-francois. |
| High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Riviere d'Auray (Brittany) and Ronce (Marennes-oleron Basin, Poitou Charentes). Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered... |
| Tipo: Text |
Palavras-chave: Genetic; Flow cytometry; Reactive oxygen species ROS; Adhesion; Hemocyte; Crassostrea gigas; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3054.pdf |
| |
|
|
| Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Mazurie, Joseph; Mazurie, Joseph; Martin, Jean-louis; Moal, Jeanne; Mathieu, Michel; Pouvreau, Stephane; Lambert, Christophe; Escoubas, Jean-michel; Nicolas, Jean-louis; Le Roux, Frédérique; Renault, Tristan; Burgeot, Thierry; Bacher, Cedric; Boudry, Pierre. |
| Complex interactions between oyster, environment and pathogens were observed during the MOREST (2001-2005) project on summer mortality events of Crassostrea gigas oysters in France. The talk will show how nutrition level increasing reproductive intensity generates a risk for pathogen infection under synergistic effect of temperature and stress. Moreover, a genetic component is associated to specific reproductive performances and spawning behaviour. To better understand origin of such resistance or susceptibility to summer mortality, other characteristics as stress susceptibility, energy management and hemocyte activities of oysters from the two phenotypes were compared. This first comparison suggests interactions between stress, reproduction and defence... |
| Tipo: Text |
Palavras-chave: Genetic; Pathologie; Mortality; Crassostrea gigas; Pacific oyster; Reproduction; Nutrition; Physilogy. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/acte-3467.pdf |
| |
|
|
| David, Elise; Boudry, Pierre; Degremont, Lionel; Tanguy, Amelie; Quere, N; Samain, Jean-francois; Moraga, D. |
| Large-scale mortality events have been observed in Pacific oyster Crassostrea gigas on the west coast of France since the early 1980s, particularly during summer. In order to understand the causes of this mortality, two generations of oysters from single-pair matings were studied in three sites on the French Atlantic coast (Baie-des-Veys, Auray and Ronce-les-Bains). The present paper examines the role of two candidate genes in the susceptibility of oysters to summer mortality, and the selective pressure exerted by such mortality on their polymorphism. Glutamine synthetase (amino-acid metabolism) and delta-9 desaturase (lipid metabolism) genes were studied in the successive generations, using polymerase chain reaction single-strand conformation polymorphism... |
| Tipo: Text |
Palavras-chave: SSCP; Mortality; Glutamine synthetase; Delta 9 desaturase; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3040.pdf |
| |
|
|
| Samain, Jean-francois. |
| French oyster farming has been subject to severe mortalities during the summer months. Results from the research program "Morest", which ran from 2000 to 2006 and examined the possible causes of these mortalities, led to the construction of a model to explain the interaction between environmental factors, oyster physiology and different opportunistic pathogens underlying oyster summer mortality. Temperature, food, reproduction and stress were the main factors required for oyster mortality. Genetically-based resistance ("R" oysters) or susceptibility ("S" oysters) to summer mortality was revealed by divergent selection. Building on these results, a literature search was made in 2007 on the molecular origin of genetic resistance to such a complex mortality... |
| Tipo: Text |
Palavras-chave: Immunity; Antibacterial activity; Host defence; Environmental stress; Crassostrea gigas. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00051/16229/13752.pdf |
| |
|
|
| Degremont, Lionel; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| The French project "Morest", coordinated by IFREMER, aims to understand the causes of the summer mortalities in Crassostrea gigas. In 2001, three sets of families were bred following a nested half-sib mating design. 17 half-sib families (HSF) were obtained in this first generation (G1) and reared in 3 sites. Significant differences in survival were observed among HSF, and some HSF showed high levels of mortality in all sites, clearly indicating a genetic basis for survival. In 2002, a second generation (G2), including divergent selection and inbred lines, was constituted. Monitoring of survival and growth of G2s were the same as in 2001. Significant differences in survival were found between the offspring of the "high" and "low" selected groups and between... |
| Tipo: Text |
Palavras-chave: Summer; Oyster culture; Juveniles mortality; Genetics; Commercial species; Breeding. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3346.pdf |
| |
|
|
| Samain, Jean-francois; Moal, Jeanne; Alayse-danet, Anne-marie; Daniel, Jean-yves; Le Coz, Jean-rene. |
| Model for Rapid Detection of Sublethal Effects of Pollutants. II. An in situ Example: Anomalous Metabolism of the Hyponeustonic Copepod Anomalocera patersoni Coinciding with an Oil Spill An unusual correlation has been obsemed between the amylase and trypsin content of a natural zooplankton population and of the hyponeustonic copepod Anomalocera patersoni and the oil spill of the "Amoco Cadiz" in 1978. This anomaly has also been obsewed in Artemia sp. cultures (San Francisco Bay strain) poisoned by copper. This phenomenon could originate from a general physiological perturbation. Such a non-specific perturbation could explain the anormal correlation between parameters which are usually independent and specifically regulated. The determination of such... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5362.pdf |
| |
|
|
| Delaporte, Maryse; Soudant, P; Lambert, C; Moal, Jeanne; Pouvreau, Stephane; Samain, Jean-francois. |
| The aim of this study was to test the effect of food quantity on energy storage and defense capacities of oysters during a reproductive cycle. One-year-old Crassostrea gigas oysters were fed two different dietary rations (4% and 12% of oyster dry weight in algal dry weight per day) in controlled experimental conditions over an annual cycle. Oyster dry weights, carbohydrate and lipid contents, energetic adenylate charge, and hemocyte parameters of oysters were significantly affected by reproductive processes related to seasonal temperature variation and, to a lesser extent, by the dietary rations. Energy parameters decreased during gametogenesis as gonads developed then increased during the gonad resorption phase. The additional energy provided to oysters... |
| Tipo: Text |
Palavras-chave: Reactive oxygen species production; Reproduction; Phagocytosis; Hemocyte parameters; Energy storage; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1549.pdf |
| |
|
| |
|
|
| Palacios, Elena; Rehault, Jean Pierre; Heras, Horacio; Marty, Yannick; Moal, Jeanne; Samain, Jean-francois. |
| In this study, lipid classes and fatty acid composition were determined in eggs of P. vannamei as a function of survival to zoea III stage. Spawns were reared individually to zoea III and grouped, according to their final survival to this larval stage, into spawns of high and low survival. Eggs of individual spawns were analyzed for lipid and fatty acid composition of neutral and polar lipids and the results were then grouped according to survival to zoea III. The lipids within each group (high and low survival to zoea III) were pooled for the separation of phospholipids and the analysis of their fatty acid composition. Higher levels of triglycerides, carotenoids, and linoleic (18: 2n-6) acid in eggs were associated with improved survival to zoea III.... |
| Tipo: Text |
Palavras-chave: Triglycerides; Phospholipid; Larval quality; Larval culture; Carotenoid. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2002/publication-786.pdf |
| |
|
|
| Huvet, Arnaud; Daniel, Jean-yves; Quere, Claudie; Dubois, Solene; Prudence, Marie; Van Wormhoudt, A; Sellos, D; Samain, Jean-francois; Moal, Jeanne. |
| A semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to estimate tissue-specific expression of two amylase genes in five different tissues of the Pacific oyster Crassostrea gigas and the experimental effects of food level on the cellular, enzymatic and gene expression changes of the digestive gland. Results indicated that both genes were transcribed at different levels depending on tissue type. A strong preferential expression of both amylase genes was observed in the digestive gland leading to high amylase activities, in accordance with the digestive function of this organ. Traces of gene expression and activity were observed in other analysed tissues. These appeared higher in labial palps than in other... |
| Tipo: Text |
Palavras-chave: Oyster; Gene expression; Food regulation; Digestive enzyme activity; Alpha amylase. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-394.pdf |
| |
|
|
| Huvet, Arnaud; Degremont, Lionel; Labreuche, Yannick; Daniel, Jean-yves; Dubrunfaut, Thomas; Boudry, Pierre; Haure, Joel; Bedier, Edouard; Ropert, Michel; Herpin, Amaury; Cunningham, Charles; Moal, Jeanne; Samain, Jean-francois. |
| Summer mortality associated with juveniles of the oyster Crassostrea gigas is the result of a complex interaction between the host, pathogens and environment. Divergent selection based on summer survival have been applied to produce families with resistant and susceptible progeny. Here, we describe the use of suppression subtractive hybridization to generate 150 clones that were differentially regulated between resistant and susceptible F2 progeny. The nucleotide sequence of these 150 clones was determined. Among the 25 unique sequences that matched with the products of known genes, those putatively implicated in energy generation (12%) and immune function (16%), systems suspected to be implicated in summer mortality, were extended and analyzed by real... |
| Tipo: Text |
Palavras-chave: Selection; Gene; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3447.pdf |
| |
|
|
| Seguineau, Catherine; Soudant, P; Moal, Jeanne; Delaporte, Maryse; Miner, Philippe; Quere, Claudie; Samain, Jean-francois. |
| The present study tested two techniques for dietary supplementation of Crassostrea gigas spat with PUFA, such as arachidonic acid (AA). The first technique consisted of a preliminary enrichment and growth of an algal concentrate (T-ISO, Isochrysis sp.) with AA dissolved in an ethanol solution, the whole culture then being fed to the spat. This enrichment increased the AA weight percentage in T-ISO neutral and polar lipids from 0.6 to 22.4% and from 0.4 to 6.8%, respectively. The second delivery technique was direct addition separately of free AA dissolved in ethanol solution and algal concentrate (T-ISO + AA) to the spat-rearing tank. To test the efficiency of these delivery techniques, oyster spat were supplemented with AA-enriched T-ISO, T-ISO + AA, and... |
| Tipo: Text |
Palavras-chave: Food supply; Arachidonic acid; Spat; Crassostrea gigas; Dietary. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1094.pdf |
| |
| Registros recuperados: 65 | |
|
|
|
