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| Registros recuperados: 136 | |
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| Prudence, Marie. |
| Two amylase genes, A and B, from the oyster Crassostrea gigas were characterized. Using PCR-RFLP, 6 and 4 alleles, respectively, were described for the amylase genes A and B. The roles of A and B amylase genes were investigated experimentally. They are expressed during larval and adult stages, and A transcripts are more abundant than B. The A transcript increases significantly with temperature, in high trophic conditions. However, A and B transcript levels do not change when food quantity increases although amylase activity augments. The level of B is correlated with dietary starch quantities, whereas the amount of A appears to remain constant ; simultaneously amylase activity decreases and the KM increases. These results suggest that expression of B is... |
| Tipo: Text |
Palavras-chave: Enzymatic analyse; Genetic polymorphism; Genes; Nutrition; Growth; Environmental effects; Oysters; Amylases; Amylases; Analyse enzymatique; Polymorphisme génétique; Gènes; Nutrition; Croissance; Effets de l'environnement; Huîtres; Amylases; Amylases. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/these-1700.pdf |
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| Huvet, Arnaud; Herpin, Amaury; Degremont, Lionel; Labreuche, Yannick; Samain, Jean-francois; Cunningham, Charles. |
| Summer mortality associated with juveniles of the oyster Crassostrea gigas is probably the result of a complex interaction between the host, pathogens and environmental factors. Genetic variability in the host appears to be a major determinant in its sensitivity to summer mortality. Previously, divergent selection criteria based on summer survival have been applied to produce oyster families with resistant and susceptible progeny. In this paper, we describe the use of suppression subtractive hybridization to generate 150 C gigas clones that were differentially regulated between resistant and susceptible F2 progeny. The nucleotide sequence of these clones was determined. In 28%, the inferred amino sequence was found to match the products of known genes, 14%... |
| Tipo: Text |
Palavras-chave: Suppression subtractive hybridization; Oysters; Differentially regulated genes; Bivalves; Bacterial challenge. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-651.pdf |
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| Degremont, Lionel; Bedier, Edouard; Soletchnik, Patrick; Ropert, Michel; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois; Boudry, Pierre. |
| Summer mortality has been reported in the Pacific oyster, Crassostrea gigas, for many years in different parts of the world. The causes of this phenomenon are complex. The multidisciplinary program "MOREST", coordinated by IFREMER, was initiated to understand the causes of summer mortality of Crassostrea gigas juveniles in France and to reduce its impact on oyster production. Within this program, three successive groups of bi-parental families were bred in a hatchery in 2001 and placed in the field during summer in three sites (Ronce, Riviere d'Auray, and Baie des Veys). This paper reports the relative importance of family, site and field placement timing for three characters of major importance for oyster production: survival, growth, and yield. At the... |
| Tipo: Text |
Palavras-chave: Juvenile; Crassostrea gigas; Oysters; Yield; Growth; Survival. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1693.pdf |
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| Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe; Phelipot, Pascal; Noiret, Christophe; Peudenier, Isabelle; Grizel, Henri. |
| For determination of ploidy levels in bivalves, three techniques are now routinely used: karyological determination. microfluorimetry and flow cytometry. This paper proposes an alternative technique which is based on determination of the optical density (OD) of stained nuclei using image analysis. A karyological and image analysis comparative experiment conducted on juveniles of Crassostrea gigas (Thunberg) and Ruditapes philippinarum (Adam & Reeve) is described and highlights the advantages of the image analysis technique. Initially developed on C. gigas and R. philippinarum, the image analysis method was easily extended to other bivalve species and to different developmental stages, as demonstrated by two experiments conducted on Ostrea edulis (L.).... |
| Tipo: Text |
Palavras-chave: Estimation bivalve triploidy; Image analysis; Triploid; Genetic; Crassostrea gigas; Oysters. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/1994/publication-3200.pdf |
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| Polo, David; Schaeffer, Julien; Teunis, Peter; Buchet, Vincent; Le Guyader, Soizick. |
| Oysters, being filter feeders, can accumulate some human pathogens such as norovirus, a highly infectious calicivirus, most common cause of acute gastroenteritis worldwide. Accumulated virus decays over a period of days to weeks, possibly rendering contaminated oysters safe again. Sensitive molecular methods have been set up for shellfish analysis but without answering the question of infectious virus detection. Using the Tulane virus (TV), a norovirus surrogate that recognizes the same ligand as human norovirus in oyster tissues, the genome and infectious virus decay rates were estimated using inverse linear regression in a Bayesian framework for genome copies. Infectivity decreased faster than genome copies but infectious viruses were detected for... |
| Tipo: Text |
Palavras-chave: Infectious virus; Genome detection; Oysters; Persistence; Shellfish outbreaks. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00436/54736/56182.pdf |
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| Broquard, Coralie; Martinez, Anne-sophie; Maurouard, Elise; Lamy, Jean-baptiste; Dégremont, Lionel. |
| Understanding sex determination in the Pacific oyster Crassostrea gigas, a sequential hermaphrodite, can provide prospective on the evolution of sex-determining systems for comparative reproduction from an evolutionary perspective. Surprisingly, this mechanism is still poorly understood. To date, sex ratio and sex change have never been studied at the individual level for a large size group and long-term monitoring. To this purpose, we performed an ambitious individual long-term follow-up (6 years) on a large population (cohort 1: 7488 oysters) produced from wild oysters, as well as for a second population produced from the cohort 1 (cohort 2: 4320 oysters). All oysters were individually sexed from 2014 to 2019. For the cohort 1, our results showed a... |
| Tipo: Text |
Palavras-chave: Sex-ratio; Sex change; Oysters; Hermaphroditism; Crassostrea gigas. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00587/69868/67845.pdf |
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| Miossec, Laurence; Goulletquer, Philippe. |
| The Pacific oyster Crassostrea gigas: from an introduced species for aquaculture to an invasive species for the ecosystem Miossec L. and Goulletquer Ph. The Pacific oyster Crassostrea gigas has been introduced worldwide for aquaculture purposes since the beginning of the last century. In most of the countries the species established broadly, emphasizing its ability to adapt to a wide range of environmental conditions. In Europe the Pacific oyster was massively introduced in the 1970s especially into France after mass mortalities of the Portuguese oyster Crassostrea angulata affected by a viral disease. Good environmental conditions in some French areas on the Atlantic coast induced successful recruitments in the following years. The population became... |
| Tipo: Text |
Palavras-chave: Europe; Non indigenous introduction; Transfers; Crassostrea gigas; Oysters; Species introduced. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3399.pdf |
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| Guillois-bécel, Y.; Couturier, E.; Le Saux, Jean-claude; Roque-afonso, A.m.; Le Guyader, Soizick; Le Goas, A.; Pernes, J.; Le Bechec, S.; Briand, A.; Robert, C.; Dussaix, E.; Pommepuy, Monique; Vaillant, C.. |
| Following the notification of nine hepatitis A cases partly clustered near an oyster growing area in the Côtes d’Armor district (Brittany, France), epidemiological, environmental and microbiological investigations were performed in order to identify the source and vehicle of contamination and devise control measures. The investigations identified 111 cases, all of whom lived or had stayed in the district. Of these cases, 87% had eaten raw bivalve molluscs and 81% had specifically eaten oysters. The raw molluscs originated from a single shellfish farm located at the north of Paimpol bay. The shellfish were probably contaminated while being stored in submersible tanks or purified in a land-based tank. They were tainted either by sewage overflows or releases... |
| Tipo: Text |
Palavras-chave: Hepatitis A; Outbreak; Oysters; Epidemiological investigations; Traceback investigations. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00066/17750/15272.pdf |
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| Gagnaire, Beatrice; Renault, Tristan; Thomas Guyon, Hélène; Burgeot, Thierry. |
| Bay of Marennes-Oleron is an important French area of reproduction for sea bass, Dicentrarchus labrax. This area is often subjected to many pollutions due to anthropic activities, including pesticides and polycyclic aromatic hydrocarbons (PAH) which cause adverse effects in aquatic organisms. The harmful effects of such contaminants on fish immune system leading to a decreased resistance against pathogens begin to be described, but remain poorly known. In this context, influence of micropolluants, like PAH, on the defense mechanisms developed by sea bass was tested. Fish were exposed five days to a soluble fraction of PAH with environmental concentration (760 ng/L). At the end of the contamination, fish were transferred to non contaminated sea water and... |
| Tipo: Text |
Palavras-chave: Phagocytosis; Vibrio; Pesticides; Pollutant; Crasssotrea gigas; Oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3317.pdf |
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| Offret, Clement; Paulino, Sauvann; Gauthier, Olivier; Château, Kevin; Bidault, Adeline; Corporeau, Charlotte; Miner, Philippe; Petton, Bruno; Pernet, Fabrice; Fabioux, Caroline; Paillard, Christine; Blay, Gwenaelle Le. |
| Digestive microbiota provides a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters Crassostrea gigas and clams Ruditapes philippinarum, two bivalves with different ecological niches. Based on the 16S rRNA region sequencing, digestive glands, seawater and sediments harbored specific bacterial communities, dominated by OTUs assigned to the Mycoplasmatales, Desulfobacterales and Rhodobacterales orders, respectively. Field implantation modified digestive bacterial microbiota of both bivalve species according to their intertidal position.... |
| Tipo: Text |
Palavras-chave: Microbiota; Oysters; Clams; Intertidal zone; Digestive gland; Metabarcoding. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73961/73320.pdf |
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| Pernet, Fabrice. |
| Le naissain d’huître creuse Crassostrea gigas est touché chaque année depuis 2008 par des mortalités causées par un microvariant de l’ostreid herpesvirus 1 (OsHV-1 μVar). Plusieurs études montrent que ces évènements de mortalité se produisent préférentiellement lorsque la température de l’eau est comprise entre 16°C et 24°C. Par conséquent, une exposition rapide des huîtres infectées par OsHV-1 à des températures supérieures à 24°C pourrait limiter les mortalités causées par le virus. Il est proposé de (1) vérifier l’hypothèse selon laquelle l’exposition à haute température réduit la mortalité des huîtres infectées par OsHV-1, et (2) déterminer si les animaux qui ont survécu suite à l’infection par OsHV-1 et au traitement thermique sont... |
| Tipo: Text |
Palavras-chave: Epidémiologie; Huître; OsHV-1; Risque; Survie; Température; Epidemiology; Oysters; OsHV-1; Risk; Survival; Temperature. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00434/54574/55953.pdf |
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| Lapegue, Sylvie; Heurtebise, Serge; Harrang, Estelle; Morga, Benjamin; Flahauw, Emilie; Sauvage, Christopher; Boudry, Pierre. |
| During the last five years, a great effort has been made to develop genomic tools in oyster species all over the world. In Europe, the Pacific cupped oyster, Crassostrea gigas, and the European flat oyster, Ostrea edulis received a special attention as they are the key species for local aquaculture. In particular, the Pacific oyster is a marine bivalve of major economical and ecological importance worldwide. Better knowledge of its physiology and its genetics contributes to optimize its aquaculture production using selective breeding or to understand its invasive behavior in some coastal areas. Current international developments of genomic resources include EST databases, BAC libraries, genome mapping and sequencing. The Genoscope (Evry, France) and the... |
| Tipo: Text |
Palavras-chave: Oysters; Crassostrea gigas; Ostrea edulis; Resistance pathogens; QTLs; Single Nucleotide Polymorphism. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12584/9454.pdf |
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| Registros recuperados: 136 | |
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