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| Registros recuperados: 30 | |
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| Delaporte, Maryse; Soudant, P; Lambert, C; Jegaden, M; Moal, Jeanne; Pouvreau, Stephane; Degremont, Lionel; Boudry, Pierre; Samain, Jean-francois. |
| Within the framework of a national scientific program named "MORtalites ESTivales de l'huitre creuse Crassostrea gigas" (MOREST), a family-based experiment was developed to study the genetic basis of resistance to summer mortality in the Pacific oyster, Crassostrea gigas. As part of the MOREST project, the second generation of three resistant families and two susceptible families were chosen and pooled into two respective groups: "R" and "S". These two groups of oysters were conditioned for 6 months on two food levels (4% and 12% of oyster soft-tissue dry weight in algal dry weight per day) with a temperature gradient that mimicked the Marennes-Oleron natural cycle during the oyster reproductive period. Oyster mortality remained low for the first two... |
| Tipo: Text |
Palavras-chave: Summer mortality; Reproduction; Reactive oxygen species ROS; Hemocyte parameters; Genetic selection; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3578.pdf |
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| Normand, Julien; Li, Ronghua; Quillien, Virgile; Nicolas, Jean-louis; Boudry, Pierre; Pernet, Fabrice; Huvet, Arnaud. |
| Pacific oyster Crassostrea gigas suffers from chronic or sporadic mortality outbreaks worldwide, resulting from infectious diseases and/or physiological disorders triggered by environmental factors. Since 2008, ostreid herpesvirus OsHV-1 μVar has been identified as the main agent responsible for mass mortality of juvenile oysters in Europe. Previous studies of genome-wide expression profiling have provided candidate genes that potentially contribute to genetically-based resistance to summer mortality. To assess their value in determining resistance to the juvenile mass mortality that has occurred in France since 2008, we analyzed the expression of 17 candidate genes in an experimental infection by OsHV-1 μVar, and in an in vivo field experiment. Individual... |
| Tipo: Text |
Palavras-chave: Molluscs; Gene expression profiling; Inhibitor of kappa B; Summer mortality; Ostreid herpesvirus. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00177/28823/27325.pdf |
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| Petton, Bruno; Bruto, Maxime; James, Adele; Labreuche, Yannick; Alunno-bruscia, Marianne; Le Roux, Frederique. |
| Successive disease outbreaks in oyster (Crassostrea gigas) beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 µvar) and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 µvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF) oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe... |
| Tipo: Text |
Palavras-chave: Pacific oysters; Summer mortality; Herpes virus; Vibrio pathogenicity; Experimental infection. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38220/36377.pdf |
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| Gagnaire, Beatrice; Soletchnik, Patrick; Madec, Patrick; Geairon, Philippe; Le Moine, Olivier; Renault, Tristan. |
| Summer mortality is an important economic concern for the Pacific oyster, Crassostrea gigas, industry all over the world and particularly in France. Outbreaks appear when oysters are in gonadal maturation. Bivalve defence mechanisms against pathogen invasion are assumed by circulating cells, the hemocytes. A field experiment was conducted in the Marennes-Oleron Basin (Charente-Maritime, France) in order to monitor hemocyte parameters, gametogenesis and mortality rates among C. gigas during 7 months from March to September 2002. Diploid (from natural bed and from hatchery) and triploid oysters were placed at 15 cm or 70 cm above sediment at Marennes-Oleron Basin. Triploid animals were included because they are considered as sterile animals. Mortality rates... |
| Tipo: Text |
Palavras-chave: Sexual maturation; Summer mortality; Triploids; Diploids; Flow cytometry; Hemocyte activities; Crassostrea gigas; Pacific oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2923.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for this trait in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences of mortality were observed during the first year in Rivière d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between... |
| Tipo: Text |
Palavras-chave: Genetic variability; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3442.pdf |
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| 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 |
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| Degremont, Lionel. |
| In order to study genetic variability for survival during summer mortality events in the oyster Crassostrea gigas, a first generation (G1) was bred in 2001. 17 G1 half-sib families (HSF) were obtained ; each HSF was reared in three sites along the French coast during the summer period. Significant differences in survival were observed among HSF indicating a genetic basis for survival. In 2002, several HSF were selected on their survival performances to constitute a divergent selection (G2) (outbreed and inbred). Significant differences in survival were found among these offspring of the 'high' and 'low' selected groups in several laboratory experiments and in all sites. Growth performance was not influenced by selection on survival. This confirms the... |
| Tipo: Text |
Palavras-chave: Juvenile; Genetic; Growth; Summer mortality; Crassostrea gigas; Juvéniles; Héritabilité; Rendement; Croissance; Mortalités estivales; Crassostrea gigas. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/these-202.pdf |
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| Degremont, Lionel. |
| During the MOREST project (2001–2006), oyster summer mortality was extensively investigated in Crassostrea gigas in France. However, significant increases in magnitude and geographic distribution of summer mortality episodes have been reported since 2008. This paper investigates the response to selection for survival, which was successfully performed between 2001 and 2003, in this new context. It also examines the relationship between the mortality and the three pathogens Vibrio aestuarianus, V. splendidus and the Ostreid herpesvirus 1 (OsHV-1). Three batches of juvenile (6-month-old) Crassostrea gigas were produced in February 2009 and tested in the field in the Marennes-Oléron Bay during summer (August and September) 2009: one control batch, one batch... |
| Tipo: Text |
Palavras-chave: Summer mortality; Crassostrea gigas; Disease resistance; Ostreid herpesvirus; Vibrio sp; Oyster. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00033/14472/11770.pdf |
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| Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Haure, Joel; Bedier, Edouard; Ropert, Michel; Moal, Jeanne; Huvet, Arnaud; Bacca, Helene; Van Wormhoudt, A; Delaporte, Maryse; Costil, K; Pouvreau, Stephane; Lambert, Christian; Boulo, Viviane; Soudant, Philippe; Nicolas, Jean-louis; Leroux, Frederique; Renault, Tristan; Gagnaire, Beatrice; Geret, Florence; Boutet, Isabelle; Burgeot, Thierry; Boudry, Pierre. |
| Summer mortality of Pacific oysters is known in several countries. However no specific pathogen has been systematically associated with this phenomenon. A complex combination of environmental and biological parameters has been suggested as the cause and is now starting to be identified. A high genetic basis was found for survival in oysters when a first generation (G1) was tested in three sites during summer. This paper presents a synthesis on physiological characteristics of two selected groups ('R' and 'S', from families selected for resistance and susceptibility to summer mortality respectively), of the second and third generations. R and S showed improvement or reduction of survival compared with the control in both field and laboratory trials... |
| Tipo: Text |
Palavras-chave: ROS; Temperature; Stress; Hemocytes; Reproduction; Genetic selection; Resistant oyster; Crassostrea gigas; Pacific Oyster; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2809.pdf |
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| 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 |
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| Fleury, Elodie; Huvet, Arnaud. |
| Summer mortality of Crassostrea gigas is the result of a complex interaction between oysters, their environment, and pathogens. A high heritability was estimated for resistance to summer mortality, which provided an opportunity to develop lines of oysters that were resistant (R) or susceptible (S) to summer mortality. Previous genome-wide expression profiling study of R and S oyster gonads highlighted reproduction and antioxidant defense as constitutive pathways that operate differentially between these two lines. Here, we show that signaling in innate immunity also operates differentially between these lines, and we hypothesize that this is at the main determinant of their difference in survival in the field. A reanalysis of our published microarray data... |
| Tipo: Text |
Palavras-chave: Mollusca; Crassostrea gigas; Gene; Immunity; CDNA microarray; Summer mortality. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00083/19423/17213.pdf |
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| Couty, Angélique. |
| The Japan oyster: Crassostrea gigas have been imported on the french coasts in the seventies and from this time it adapted to this environment. Since, it became the main oyster producted in France. But ,since twenty years C. gigas presents an anormaly and important mortality eah year in the period of summer. The syndrome known as summer mortality, appears particulary in mid-june. This mortality can affected 50% of the culture. Many studies have brought elements in the comprehension of the condition of apparition of this mortalilities. Temperature seems to play an important rule with reproductive maturation. But also, the deep ofwater could be associated to this mass mortality. The study began in march 2003 and characterize more precisely the summer... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Mortalité estivale; Croissance; Maturation; Environnement; Crassostrea gigas; Summer mortality; Growth; Maturation; Environment. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00306/41767/40980.pdf |
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| Samain, Jean-francois; Ropert, Michel; Bedier, Edouard; Soletchnik, Patrick; Mazurie, Joseph; Le Coz, Florence; Blin, Jean-louis; Mille, Dominique; Pajot, Régis; Haffray, Patrick; Bacher, Cedric; Grangere, Karine; Grangere, Karine; Pouvreau, Stephane; Bourles, Yves; Gohin, Francis; Woerther, Patrice; Boudry, Pierre. |
| Summer mortality has been reported in the Pacific oyster, Crassostrea gigas, for many years in Japan, US and Europe. It affects both adults and juveniles and the causes of this phenomenon are complex. Environmental, physiological or pathological putative causes were studied all over the world. Recently, the MOREST project ((MORtalitEStivale) a multidisciplinary project (2001-2005) focused on his problem led to a better understanding of this phenomenon in France. The results showed in these geographical conditions, the main interactions between the oysters, their environment and certain pathogens. |
| Tipo: Text |
Palavras-chave: Interaction model; Environmental parameters; Summer mortality; Crassostrea gigas; Pacific oyster. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/acte-3476.pdf |
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| Sauvage, Christopher; Boudry, Pierre; De Koning, D. -j.; Haley, C. S.; Heurtebise, Serge; Lapegue, Sylvie. |
| P>Summer mortality is a phenomenon severely affecting the aquaculture production of the Pacific oyster (Crassostrea gigas). Although its causal factors are complex, resistance to mortality has been described as a highly heritable trait, and several pathogens including the virus Ostreid Herpes virus type 1 (OsHV-1) have been associated with this phenomenon. A QTL analysis for survival of summer mortality and OsHV-1 load, estimated using real-time PCR, was performed using five F-2 full-sib families resulting from a divergent selection experiment for resistance to summer mortality. A consensus linkage map was built using 29 SNPs and 51 microsatellite markers. Five significant QTL were identified and assigned to linkage groups V, VI, VII and IX. Analysis of... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Herpes virus; Pacific oyster; QTL mapping; Summer mortality. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12241/9063.pdf |
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| Huvet, Arnaud; Normand, Julien; Fleury, Elodie; Quillien, Virgile; Fabioux, Caroline; Boudry, Pierre. |
| Summer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of reproductive effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P<0.001). with an estimated mean difference of 12.5%, whereas,... |
| Tipo: Text |
Palavras-chave: Bivalve mollusc; Crassostrea gigas; Reproduction; Selected lines; Summer mortality. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11766/8502.pdf |
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| Registros recuperados: 30 | |
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