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Registros recuperados: 170 | |
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Lafont, Maxime; Vergnes, Agnes; Vidal-dupiol, Jeremie; De Lorgeril, Julien; Gueguen, Yannick; Haffner, Philippe; Petton, Bruno; Chaparro, Cristian; Barrachina, Celia; Destoumieux-garzon, Delphine; Mitta, Guillaume; Gourbal, Benjamin; Montagnani, Caroline. |
Over the last decade, innate immune priming has been evidenced in many invertebrate phyla. If mechanistic models have been proposed, molecular studies aiming to substantiate these models have remained scarce. We reveal here the transcriptional signature associated with immune priming in the oyster Crassostrea gigas. Oysters were fully protected against Ostreid herpesvirus 1 (OsHV-1), a major oyster pathogen, after priming with poly(I·C), which mimics viral double-stranded RNA. Global analysis through RNA sequencing of oyster and viral genes after immune priming and viral infection revealed that poly(I·C) induces a strong antiviral response that impairs OsHV-1 replication. Protection is based on a sustained upregulation of immune genes, notably genes... |
Tipo: Text |
Palavras-chave: Innate immunity; Priming; OsHV-1; Antiviral response; Immune memory; Oyster; POMS; Poly(I·C); Interferon; Transcriptomic. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72580/71541.pdf |
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Suquet, Marc; Gonzalez, Ricardo; Lebrun, Luc; Queau, Isabelle; Mingant, Christian; Robert, Rene. |
Controlled reproduction of the European flat oyster requires the development of tools adapted to this species, including a practical anaesthesia and gonad sampling protocol to facilitate sex determination and the verification of gametogenesis. Three replicate groups of 10 oysters (mean weight +/- SD: 29.9 +/- 8.5 g) were anaesthetised in 5 L containers using magnesium chloride designed either for laboratory (Flucka (R)) or agricultural (Dead Sea Work (R): DSW) use, at two concentrations (50 or 72 g L-1). No significant differences were observed in the percentages of oysters anaesthetised or subsequent oyster mortality with the different anaesthetics or concentrations, but increasing water temperature from 14.9 to 18.8 degrees C significantly increased the... |
Tipo: Text |
Palavras-chave: Oyster; Ostrea edulis; Anaesthesia; Magnesium chloride; Gonad sampling. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00018/12907/9876.pdf |
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Benabdelmouna, Abdellah; Ledu, Christophe. |
We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploid lines to tetraploids used as broodstock, avoiding a triploid step with the risk of transferring undesirable traits from highly fecund triploids. High variability in the level of cytogenetic stability was found among the different tetraploid oysters tested showing that induction method has an important impact on the long-term cytogenetic stability of the... |
Tipo: Text |
Palavras-chave: Oyster; Tetraploid induction; Mosaicism; Aneuploidy; Cytogenetic stability. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38924/37464.pdf |
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Silva,Ana I.M.; Vieira,Regine H.S.F.; Menezes,Francisca G.R.; Fonteles-Filho,Antonio A.; Torres,Regina C.O.; Sant'Anna,Ernani S.. |
This study was aimed at evaluating the microbiological quality of mangrove oysters (Crassostrea rhizophorae), collected at a natural oyster bed in the estuary of Cocó river (Fortaleza, Ceará, Brazil). MPN values were used for estimating the total (TC) and fecal (FC) coliforms and Enterococcus spp. TC and FC MPN values in the whole muscle and intervalve liquid ranged from <1.8 to >1,600/g and from <1.8 to 920/g, respectively. The MPN estimates for Enterococcus spp. were between <3.0 and >1,100/g. No correlation was found between the physico-chemical parameters (temperature, salinity and pH) of the surrounding water and the bacteriological contamination levels found in the tested oysters. The only correlation found was between TC and FC... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oyster; Total and fecal coliforms; Enterococci; Bacteriocins. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822004000100021 |
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Suquet, Marc; Pouvreau, Stephane; Queau, Isabelle; Boulais, Myrina; Le Grand, Jacqueline; Ratiskol, Dominique; Cosson, Jacky. |
n brooding mollusc species that incubate larvae before their release in seawater, the biology of gametes remains poorly explored. The present study describes some biological characteristics of sperm of the European flat oyster, a native species that has been over-exploited in the past and is nowadays classified as an endangered species in Europe. Flat oysters were collected by divers in the Rade de Brest (Finistère, France), during its natural reproduction period. Gonadal pH is acidic (6.31 ± 0.10). Spermatozoa are clustered in spermatozeugmata, an acellular structure in which the sperm heads are embedded. After their transfer in seawater, spermatozeugmata have a mean diameter of 64 ± 3 μm and they release free spermatozoa for a mean duration of... |
Tipo: Text |
Palavras-chave: Oyster; Ostrea edulis; Brooding species; Sperm; Spermatozeugmata; Endangered species. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56539/58245.pdf |
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Arzul, Isabelle; Miossec, Laurence; Blanchet, Estelle; Garcia, Celine; Francois, Cyrille; Joly, Jean-pierre. |
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. After its first description in June 1979 in L'Ile Tudy, Brittany, the parasite rapidly spread to all French oyster farming areas and in other European countries through transfers of live molluscs. Bonamiosis and marteiliosis, another protozoan disease appeared in the seventies, drastically reduced the French flat oyster production from 20 000 tonnes in 1970 to less than 2000 tonnes after 1981. In 2001, about 1650 t of flat oysters were marketed in France. The production is restricted to several areas specialised in reproduction, growth and/or marketing, and depends on transfers of animals. Most important production... |
Tipo: Text |
Palavras-chave: Bonamia ostreae; Parasitology; Pathology; Ostrea edulis; Oyster. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-6381.pdf |
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Renault, Tristan; Cochennec, Nathalie; Grizel, Henri. |
The protozoan Bonamia ostreae (Ascetospora) is the etiological agent of bonamiosis, or hemocyte disease of the European fiat oyster, Ostrea edulis (Pichot et al., 1980). Since this infection was first reported from the coast of Brittany (Comps et al., 1980), the parasite has spread rapidly along the French Atlantic coasts (Grizel & Tigé, 1982), and in the European countries including the UK, Holland, lreland and Spain (Bannister & Key, 1982; Van Banning, 1982; Polanco et al., 1984). Under the EEC Council Directive 91/67, this parasitic protozoan is included in list II of Annex A. Serious pathogen agents for molluscs that should be obligatorily declared are placed in this list |
Tipo: Text |
Palavras-chave: Infection; Protozoan; Oyster; Ostrea edulis; Bonamia ostreae. |
Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/publication-2892.pdf |
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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 |
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Goulletquer, Philippe. |
NOAA’s National Marine Fisheries Services (NMFS) received a petition to list the Eastern oyster (Crassostrea virginica) as either threatened or endangered under the Endangered Species Act (ESA). The Eastern oyster is an emblematic species in the US coastal states, playing a significant role at various levels: shaping coastal social communities, providing a commercial activity (public fishery & aquaculture) and recreational - amenity benefits, and as a keystone species in highly diverse and sensitive ecosystems (estuaries). This petition is likely the result of concerns regarding the partial collapse of public fisheries in several states as well as from the resulting damages to this species induced by severe hurricanes. A Biological Review Team (BRT)... |
Tipo: Text |
Palavras-chave: Biology; Habitat threats; Predation; Disease; Bivalvia; Crassostrea virginica; Oyster; Recommendations. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00043/15458/12833.pdf |
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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 |
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Fleury, Elodie; Fabioux, Caroline; Lelong, C; Favrel, P; Huvet, Arnaud. |
Through differential screening between oyster families selected for high and low summer survival, we have characterized a new transforming growth factor-beta (TGF-beta) superfamily member. This novel factor, named oyster-gonadal-TGF beta-like (og-TGF beta-like), is synthesized as a 307 amino acid precursor and displays 6 of the 7 characteristic cysteine residues of the C-terminal, mature peptide. Sequence comparison revealed that og-TGF beta-like has a low percentage of identity with other known TGF-beta superfamily members, suggesting that og-TGF beta-like is a derived member of this large superfamily. Real-time PCR (RT-PCR) analysis in different oyster tissues showed that og-TGF beta-like is specifically expressed in both male and female gonads, at... |
Tipo: Text |
Palavras-chave: Reproduction; Oyster; Gene expression; Transforming growth factor; Bivalve mollusc. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3899.pdf |
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Bigot, Laetitia; Zatylny-gaudin, Celine; Rodet, Franck; Bernay, Benoit; Boudry, Pierre; Favrel, Pascal. |
Gonadotropin-releasing hormone (GnRH), a key neuropeptide regulating reproduction in vertebrates has now been characterized in a number of non-vertebrate species. Despite the demonstration of its ancestral origin, the structure and the function of this family of peptides remain poorly known in species as distant as lophotrochozoans. In this study, two GnRH-related peptides (Cg-GnRH-a and CgGnRH-G) were characterized by mass spectrometry from extracts of the visceral ganglia of the Pacific oyster Crassostrea gigas. These peptides showed a high degree of sequence identity with GnRHs of other mollusks and annelids and to a lesser extent with those of vertebrates or with AKH and corazonins of insects. Both the mature peptides and the transcript encoding the... |
Tipo: Text |
Palavras-chave: Mollusk; Bivalve; Oyster; Neuroendocrinology; Reproduction; GnRH. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19003/17477.pdf |
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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 |
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Behrens, Daphne; Rouxel, Julien; Burgeot, Thierry; Akcha, Farida. |
Herbicides are one of the major classes of pollutants contaminating coastal waters over the world. Among them, diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a phenylurea herbicide frequently detected in oyster-producing area, known to be toxic for this important exploited non-target species. With the aim to investigate the mechanisms by which diuron displays its toxicity in oyster, the implication of both biotransformation and oxygen reactive species (ROS) production was studied considering embryotoxicity and genotoxicity as endpoints. Comparative embryotoxicity and genotoxicity of diuron and its main metabolites (DCPMU, DCPU and 3,4-DCA) were thus studied on oyster larvae by the embryo-larval bioassay on D larvae and the comet assay on trochophore... |
Tipo: Text |
Palavras-chave: Oyster; Herbicide; Embryotoxicity; Genotoxicity; Oxidative stress; Biotransformation. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00324/43521/43053.pdf |
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Normand, Julien; Le Pennec, Marcel; Boudry, Pierre. |
We compared the temporal dynamics of gametogenesis in diploid and triploid Pacific oysters (Crassostrea gigas) using histology. Oysters were reared in an estuarine farming site in Brittany over 3 years and their gametogenesis was monitored over the exceptionally hot summer of 2003. Both diploids and triploids showed active gametogenesis, but a high proportion of triploids remained at early stages of gonad development. Gametogenesis of triploids was characterized by the simultaneous occurrence of gonias and immature cytes together with mature gametes rather than overall retardation, though some triploids showed complete gonad maturation. Evidence of spawning was seen in both groups, and the quantity of germinal products emitted appeared to be similar in... |
Tipo: Text |
Palavras-chave: Triploidy; Crassostrea gigas; Oyster; Gametogenesis. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4152.pdf |
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Pouliquen, Hervé; Le Bris, Hervé; Buchet, Vincent; Pinault, Louis. |
Marine fish farms use many antibacterial agents to prevent or fight bacterial diseases. The major part of the orally supplied drugs reach the environment, either directly due to excessive feeding and reduced appetite of the cultured fish, or indirectly after passing through the fish. Some of the drugs entering the environment may be taken up by bivalves. Comparative contamination and decontamination of Japanese oyster Crassostrea gigas and blue mussel Mytilus edulis were studied when these bivalves were kept during 10 d in seawater containing oxytetracycline (OTC) or oxolinic acid (OA) at concentrations of 0.15 and 1.50 mg l(-1). After the 10 d exposure at the seawater concentrations of 0.15 and 1.50 mg l(-1), OTC and OA concentrations in bivalve tissues... |
Tipo: Text |
Palavras-chave: Mussel; Oxolinic acid; Oxytetracycline; Oyster. |
Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00282/39359/39437.pdf |
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Registros recuperados: 170 | |
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