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| Registros recuperados: 82 | |
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| Renault, Tristan; Cochennec, Nathalie. |
| Grossly visible lesions of the ctenidia and occasional mortalities in Japanese oyster Crassostrea gigas from the Atlantic French coast were reported in 1992-1993. From August 1992 to March 1993, 235 living oysters were collected to determine the cause of tissue lesions and mortalities. Microscopical examination of fixed, stained sections revealed that 53 2% of these oysters had ctenidia and mantle lesions associated with irregular basophllic and Feulgen positive cytoplasmic inclusion bodies. Ultrastructurally, the infectious agent was a chlamydia-like organism. Indirect fluorescent and peroxidase conjugated antibody tests suggested that this agent might share common antigens with the prokaryotic agent Chlamydia psittaci, strain ovis |
| Tipo: Text |
Palavras-chave: Mantle; Ctenidia; Chlamydia like organisms; Pacific oyster; Crassostrea gigas. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/publication-2896.pdf |
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| Le Deuff, Rose-marie. |
| Among the marine molluscs, Pacific oyster, Crassostrea gigas, is actually the most reared species in the world. Noticeably in France, where it was imported between 1960 and 1970, and replaced Portuguese oyster, Crassostrea angulata. Intensification of breeding and the associated introductions of new species may be hazardous. Indeed, they might be responsible for the appearance and the dissemination of new diseases in bivalve molluscs. In addition to these observations, the quasi monobreeding of C. gigas in France enhances the necessity to develop research concerning the diagnosis of pathologies affecting this species, namely the diagnosis of viral diseases. Several families of viruses have been described within marine bivalves molluscs. The purpose of this... |
| Tipo: Text |
Palavras-chave: Mollusques bivalves; Crassostrea gigas; Huître japonaise; Pathologie; Iridovirus; Herpèsvirus; Diagnostic; Bivalve molluscs; Crassostrea gigas; Pacific oyster; Pathology; Iridovirus; Herpesvirus; Diagnosis. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00107/21792/19367.pdf |
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| Ernande, Bruno; Boudry, Pierre; Heurtebise, Serge; Haure, Joel; Martin, Jean-louis. |
| Introduction : Growth and survival are the life-history traits of the most interest for oyster production since they determine biomass output (growth x survival). This study aimed to investigate whether there is genetic basis for growth, survival and their plasticity to know if a selection program is conceivable for these traits. Material and Methods : Nested half-sibs mating design was used to produce families of oysters: 5 males were each mated to three females producing 5 half-sibs families, each containing 3 full-sib families. At 15 months of age (May 1999), each full-sibs family was randomly split into five groups which were given different treatments. Two groups were placed in a constant environment: one with low food resources and another with high... |
| Tipo: Text |
Palavras-chave: Genotyic; Plasticity; Survival; Growth; Genetic; Crassostrea gigas; Pacific oyster. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/acte-3498.pdf |
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| Renault, Tristan; Stokes, Nancy; Chollet, Bruno; Cochennec, Nathalie; Berthe, Franck; Gerard, Andre; Burreson, Eugene. |
| Two cases of haplosporidian infection occurred during 1993 in Pacific oysters Crassostrea gigas from the French Atlantic coast. The localization and ultrastructure of the plasmodia are described. In situ hybridization of infected tissue sections was conducted with DNA probes for oyster-infecting haplosporidians. The Haplosporidium nelsoni-specific DNA probe MSX1347 hybridized with the C. gigas parasite, and the H, costale-specific probe SSO1318 did not hybridize. Total genomic DNA was extracted from the infected tissue sections for polymerase chain reaction (PCR) amplification of the haplosporidian. PCR amplifications with H. nelsoni-specific primers and with 'universal' actin primers did not yield the expected products of 573 and 700 bp, respectively. A... |
| Tipo: Text |
Palavras-chave: Haplosporidium nelsoni; Haplosporidiosis; Crassostrea gigas; Pacific oyster. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-821.pdf |
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| Bouilly, Karine; Leitao, Alexandra; Mccombie, Helen; Miramand, Pierre; Lapegue, Sylvie. |
| Aneuploidy is the alteration of the normal diploid chromosome number. In the Pacifie oyster, Crassastrea gigas, hypodiploid cells have regularly been reported as have a negative correlation between this phenomenon and growth and evidence for a genetic basis. We previously demonstrated a positive relationship between a pollutant, atrazine, and aneuploidy in Crassastrea gigas adults and juveniles. To evaluate the persistence of this impact, the present study focused on a sample of the same juveniles previously exposed to different atrazine treatments (0.0 1 mg/l which represents a peak value found in a polluted environment and 0.1 mg/l) for three and a half months. Then, we evaluated them for aneuploidy after another two and a half months in non polluted... |
| Tipo: Text |
Palavras-chave: Cadmium; Atrazine; Pollutant; Pacific oyster; Aneuploidy. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-2852.pdf |
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| Bouilly, Karine; Leitao, Alexandra; Chaves, Raquel; Guedes Pinto, Henrique; Boudry, Pierre; Lapegue, Sylvie. |
| Aneuploidy has previously been observed in the Pacific oyster, Crassostrea gigas, and shown to be negatively correlated with growth. Moreover, a significant impact of atrazine exposure has been described in C. gigas, and persistence of that effect has been observed between generations. Evidence of differential chromosome loss has been demonstrated in aneuploid karyotypes of C. gigas using the G-banding technique. Pairs 1, 5, 9, and 10 are characterized by the loss of 1 chromosome. As restriction enzyme (RE) digestion chromosome banding allows a better identification of chromosome pairs, we used this technique to identify which chromosomes are affected when aneuploidy is increased by exposure to atrazine. The progeny of oysters contaminated by atrazine were... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Pacific oyster; Restriction enzyme digestion chromosome banding; Atrazine; Aneuploidy; Crassostrea gigas; Huître creuse; Marquage chromosomique par digestion d'enzymes de restriction; Atrazine; Aneuploïdie. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/2005/publication-654.pdf |
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| Boudry, Pierre. |
| To date, the most significant genetic improvement for the production of Pacific oyster (Crassostrea gigas) has been obtained through the production of triploids, especially since the development of tetraploids. Quantitative genetics studies suggest that significant gains, for disease resistance or other traits, could be obtained in diploids. However, the limited extent of hatchery-propagation (versus natural recruitment) and/or various technical difficulties and biological characteristics of the species have retarded the development of selective breeding programs. In the U.S.A., Australia and New Zealand, family-based selective breeding programs have recently been initiated to improve growth, disease tolerance and yield. In Europe, where both natural and... |
| Tipo: Text |
Palavras-chave: Microsatellite markers; Crassostrea gigas; Selective breeding; Triploid; Pacific oyster; Genetic. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3451.pdf |
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| Hedgecock, Dennis; Gaffney, Patrick M.; Goulletquer, Philippe; Guo, Ximing; Reece, Kimberly; Warr, Gregory. |
| An international community of biologists presents the Pacific oyster Crassostrea gigas as a candidate for genome sequencing. This oyster has global distribution and for the past several years the highest annual production of any freshwater or marine organism (4.2 million metric tons, worth $3.5 billion US). Economic and cultural importance of oysters motivates a great deal of biologic research, which provides a compelling rationale for sequencing an oyster genome. Strong rationales for sequencing the oyster genome also come from contrasts to other genomes: membership in the Lophotrochozoa, an understudied branch of the Eukaryotes and high fecundity, with concomitantly high DNA sequence polymorphism and a population biology that is more like plants than any... |
| Tipo: Text |
Palavras-chave: Genomics; Evolutionary and ecological; Nucleotide diversity; Lophotrochozoa; Crassostrea gigas genome sequence; Pacific oyster. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-2128.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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| Gagnaire, Beatrice; Thomas Guyon, H; Burgeot, Thierry; Renault, Tristan. |
| The shellfish industry is an important economic activity in France, occurring mostly in estuarine zones subject to pollution due to anthropogenic activities. The harmful effects of pollutants on species inhabiting these estuarine zones are not well known. Among marine species, bivalve mollusks---particularly Pacific oyster, Crassostrea gigas-may serve a model of interest. The species is sedentary and filter-feeding, which favors bioaccumulation of pollutants in their tissues. Oysters may be suitable for studies on disturbance by pollutants of physiological activities, among which defense mechanisms are poorly documented in bivalves. In this study, effects of pollutants on hemocyte functions were monitored in Pacific oyster, C. gigas. Hemocytes were exposed... |
| Tipo: Text |
Palavras-chave: Toxicity; Pesticides; PCBs; PAHs; Crassostrea gigas; Pacific oyster; Hemocytes; Flow cytometry; Cellular activities. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1695.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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| Pouvreau, Stephane; Rambeau, Marc; Cochard, Jean-claude; Robert, Rene. |
| Classically, investigation of the internal morphology and composition of molluscs and especially bivalves relies on destructive method (biometry, biochemistry and histology). These techniques have given essential information, but in contrast are time consuming and lead to the irreversible loss of the animal while they don't allow integration of the various levels of molecular-to-organism functioning. The aim of this study is to analyze for the first time the potential of NMR (nuclear magnetic resonance) imaging (MRI) to depict, with sufficient resolution and satisfactory contrast, the anatomy of a bivalve model, the Pacific oyster, Crassostrea gigas, without opening it. MRI experiments were carried out at 19 °C in several non-anaesthetized adult Pacific... |
| Tipo: Text |
Palavras-chave: In vivo physiology; Aquaculture; Anatomy; MRI; Pacific oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1819.pdf |
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| Boudry, Pierre; Degremont, Lionel; Bedier, Edouard; Pouvreau, Stephane; Normand, Julien; Ernande, Bruno. |
| To date, the most significant method to genetically reduce reproductive effort in the Pacific oyster (Crassostrea gigas) has been through the production of triploids, especially since the development of tetraploid lines allowing the breeding of 'natural' triploids. Gametogenesis of triploid oysters is strongly reduced compared with diploids, although they are not fully sterile and can produce viable gametes and some progenies when crossed with diploids. Reduced reproductive allocation and higher heterozygocity are commonly proposed as the main reasons why triploids often present superior yield compared with diploids. Temperature and food availability are known to favour gametogenesis in triploids, but the existence of genetic variation for this trait... |
| Tipo: Text |
Palavras-chave: Selective breeding; Reproduction; Genetic variation; Crassostrea gigas; Pacific oyster; Genetic. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3445.pdf |
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| 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 |
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| Registros recuperados: 82 | |
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