|
|
|
| Registros recuperados: 858 | |
|
|
| Labreuche, Yannick; Lambert, Christophe; Soudant, Philippe; Boulo, Viviane; Huvet, Arnaud; Nicolas, Jean-louis. |
| The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster; Pathogenesis; Vibrio aestuarianus; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2182.pdf |
| |
|
| |
|
|
| Escoubas, Jean-michel; Montagnani, Caroline; Le Roux, Frédérique; De Lorgeril, Julien; Berthe, Franck; Bachere, Evelyne. |
| We isolated complementary DNA (Cg-TIMP) from Crassostrea gigas that codes for a protein highly homologous to vertebrate tissue inhibitors of metalloproteinases (TIMPs). In vertebrates, TIMPs are multifunctional proteins that play a key role in extracellular matrix metabolism. They are involved in physiological processes (e.g. embryonic development, damage repair, angiogenesis) and pathological processes (e.g. inflammatory reactions, cancer). |
| Tipo: Text |
Palavras-chave: Proteine; Cg TIMP; ADN; Crassostrea gigas. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3268.pdf |
| |
|
|
| Delaporte, Maryse; Chu, Fu-lin; Langdon, Chris; Moal, Jeanne; Lambert, Christophe; Samain, Jean-francois; Soudant, Philippe. |
| The aim of this study was to assess the effect of dietary eicosapentaenoic acid (20:5n-3) on hemocyte parameters such as hemocyte concentration, phagocytosis, and non-stimulated reactive oxygen species (ROS) production in Pacific oysters Crassostrea gigas, as well on proximate biochemical and fatty acid compositions. One-year-old oysters (C. gigas) were fed T-Isochrysis aff. galbana(T-Iso), which is low in 20:5n-3, either alone or with supplements of a lipid emulsion rich in 20:5n-3 at 1%, 10% or 50% (dry weight of the algal ration) for up to 7 weeks. Changes in gill fatty acid composition demonstrated that the lipid emulsion was well ingested by oysters during the dietary conditioning. Biochemical analysis indicated that oysters fed supplements of 50%... |
| Tipo: Text |
Palavras-chave: Polyunsaturated fatty acids; Immunology; Hemocytes; Eicosapentaenoic acid 20 : 5n 3; Crassostrea gigas; Bivalves. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2604.pdf |
| |
|
|
| Suquet, Marc; Labbe, C.; Brizard, Raphael; Donval, Anne; Le Coz, Jean-rene; Quere, Claudie; Haffray, P.. |
| Changes in sperm features during the movement phase are especially interesting to study in external fertilization species whose sperm duration movement is long because this implies a significant adaptation of moving cells to the external medium. This study describes the changes in tetraploid Pacific oyster sperm characteristics in relation to time post activation. Sperm individually collected on three tetraploid males were activated in seawater. Their features were analysed over a 24 h period and compared to a sperm pool collected on three diploid males as a reference. The percentage of motile spermatozoa, the intracellular ATP content, and the fine structure of spermatozoa were studied in relation to time post activation. Furthermore, the fertilisation... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Sperm; Tetraploid; Motility; ATP; Ultrastructure. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11756/8639.pdf |
| |
|
|
| Richard, Marion; Bec, Beatrice; Vanhuysse, Charles; Mas, Sébastien; Parin, David; Chantalat, Camila; Le Gall, Patrik; Fiandrino, Annie; Lagarde, Franck; Mortreux, Serge; Ouisse, Vincent; Rolland, Jean-luc; Degut, Anaïs; Hatey, Elise; Fortune, Martine; Roque D'Orbcastel, Emmanuelle; Messiaen, Gregory; Munaron, Dominique; Callier, Myriam; Oheix, Jocelyne; Derolez, Valerie; Mostajir, Behzad. |
| Oysters modify the planktonic microbial community structure by their filtration and NH4 excretion activities. While many studies have been conducted on this subject with adult oysters, none had been carried out in situ with juveniles. Pacific oyster juveniles (Magallana gigas, previously Crassostrea gigas) died massively all over the world since 2008 in relation with OsHV-1 infection. During mortality episodes, sick and dead oysters are not separated from healthy live ones, and left to decay in the surrounding environment, with unknown consequences for the nutrient cycle and planktonic microbial components (PMC). The present study aimed to elucidate for the first time the interactions between oyster juveniles and PMC during a mortality episode. Innovative... |
| Tipo: Text |
Palavras-chave: Magallana gigas; Crassostrea gigas; Spat; OsHV-1 mu Var; Mortality; Picoplankton; Heterotrophic flagellates; Ciliates; Uronema; Balanion. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00474/58559/61115.pdf |
| |
|
| |
|
|
| 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 |
| |
|
|
| Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne. |
| In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Genomic library; Microbiology; Defensin; Oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2127.pdf |
| |
|
|
| Fleury, Pierre-gildas; Mazurie, Joseph; Ropert, Michel; Soletchnik, Patrick; Le Coz, Florence. |
| The wide range of data from the French Ifremer/REMORA network, collected since 1993 allow a global characterization of mortalities of 1-year old and 2-years old cupped oysters Crassostrea gigas, that are cultivated in the main French oyster areas (Fleury et al, 2003), and thus a better understanding of the causes of these mortalities (Ifremer /MOREST project). The average annual mortalities on intertidal sites range from 10 to 20%. Most of the mortalities take place in Spring and Summer. 1-year oyster mortalities occur in Marennes and several sites in Brittany whilst 2-years oyster mortalities occur in the same sites and in baie des Veys (Normandy). In addition, 2-years oyster mortalities appear more variable according to different annual surveys.... |
| Tipo: Text |
Palavras-chave: Meteorolgical factors; Phytoplankton; REMORA; Mortalities; Oysters; Crassostrea gigas. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4547.pdf |
| |
|
|
| Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Costil, K. S.; Dubois, Brice; Degremont, Lionel; Bouget, Jean-francois; Martin, Jean-louis; Enriquez-diaz, M.; Faury, Nicole; Le Moine, Olivier; Renault, Tristan; Gagnaire, Beatrice; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| Field characterization of summer mortality was performed in France in the frame of the Morest project. Natural and hatchery spat were compared between three oyster production areas in France. Regardless of the natural or hatchery origin, oysters died during the reproduction period after temperature reaches 19 degree C. Thus, in southern areas, temperature accelerated gametogenesis of small spat (10mm) as well as adults, and mortality appeared for the two age classes. In contrast, sexual maturation proceeded more slowly in northern where spat mortality was lower compared to 18 months old oysters. However, critical gametogenesis and temperature were not sufficient to induce mortalities, as observed in examples with stable environment. Alternatively sediment... |
| Tipo: Text |
Palavras-chave: Seasonal variation; Oyster culture; Mortality causes; Hatcheries; Gametogenesis; Environmental factors; Crassostrea gigas; Oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3348.pdf |
| |
|
|
| Gay, Melanie; Renault, Tristan; Le Roux, Fredérique. |
| The French oyster production is mainly based on the pacific oyster, Crassos/rea gigas. However, for several years, C. gigas spat has suffered severe mortality outbreaks. A multifactorial etiology implicating environment, oyster physiology, genetics and pathogens is heavily suspected. A herpesvims and bacteria belonging to the Vihrio s\p/endidus polyphyletic group have been isolated From summer mortality outbreaks. Moreover, several strains belonging to the genus Vibrio have been identified as pathogen for different mollusk species. However, few tools are available for the identification of these Vibrios and for the characterization of the virulence of the pathogenic strains. |
| Tipo: Text |
Palavras-chave: Mortality; Vibrio splendidus; Crassostrea gigas. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-2854.pdf |
| |
|
| |
|
|
| 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 |
| |
|
|
| Bouilly, Karine; Chaves, R.; Leitao, A.; Benabdelmouna, Abdellah; Guedes Pinto, H.. |
| Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or ribosomal DNA sequences. However, regarding chromosome identification, no study has been conducted with simple sequence repeats (SSRs). FISH was used to probe the physical organization of three particular SSRs, (GGAT)(4), (GT)(7) and (TA)(10) onto metaphase chromosomes of the Pacific oyster, Crassostrea gigas. Hybridization signals were observed in all the SSR probes, but the distribution and intensity of signals varied according to the oligonucleotide repeat. The intercalary, centromeric and telomeric bands were observed... |
| Tipo: Text |
Palavras-chave: Simple sequence repeats (SSRs); Mollusks; Fluorescence in situ hybridization (FISH); Crassostrea gigas; Chromosome identification. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6132.pdf |
| |
|
| |
|
|
| Mccombie, Helen; Lapegue, Sylvie; Cornette, Florence; Ledu, Christophe; Boudry, Pierre. |
| Alterations of chromosome number have been observed in the somatic tissue of Crassostrea gigas diploids and artificial polyploids bred in this species. Tetraploid animals with lower chromosome counts in some or all of their somatic tissue are considered undesirable as parents either for commercial triploids (produced via a cross with diploids) or for tetraploid breeding because (1) they may confer the tendency to lose chromosomes and revert to lower ploidy levels to their offspring or (2) their offspring could have a lower ploidy directly because of potential links between somatic and gametic chromosome loss. The present study evaluated the phenomenon in bi-parental tetraploid families bred from parents of differing ploidy quality, including a... |
| Tipo: Text |
Palavras-chave: Tetraploid; Chromosome; Genetic; Crassostrea gigas; Oyster. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3435.pdf |
| |
|
| |
|
|
| Gagnaire, Beatrice; Gay, Melanie; Huvet, Arnaud; Daniel, Jean-yves; Saulnier, Denis; Renault, Tristan. |
| To assess the impact of pollution induced by pesticides on Pacific oyster, Crassostrea gigas, health in France, in vivo effects of combined pesticide exposure and bacterial challenge on cell activities and gene expression in hemocytes were tested using flow cytometry and real-time PCR. As a first step, an in vivo model of experimental contamination was developed. Pacific oysters were exposed to a mixture of eight pesticides (atrazine, glyphosate, alachlor, metolachlor, fosetyl-alumimium, terbuthylazine, diuron and carbaryl) at environmentally relevant concentrations over a 7-day period. Hemocyte parameters (cell mortality, enzyme activities and phagocytosis) were monitored using flow cytometry and gene expression was evaluated by real-time PCR (RT-PCR).... |
| Tipo: Text |
Palavras-chave: Gene expression; Flow cytometry; Vibrio splendidus; Pathogenesis; Phagocytosis; Hemocyte; Pesticides; Bivalve immunity; Crassostrea gigas; Pacific oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3022.pdf |
| |
|
| |
| Registros recuperados: 858 | |
|
|
|
