Consulta: creatorFacets:"Seguineau, Catherine"
Registros recuperados: 8
Data/hora: 03/06/2024 05:48:00

Gametogenetic cycle and reproductive effort assessed by two methods in 3 age classes of Pacific oysters, Crassostrea gigas, reared in Normandy
Provedor de dados: 5
Autores: Royer, J; Seguineau, Catherine; Park, K; Pouvreau, Stephane; Choi, K; Costil, K.
Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked lmmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which...
Tipo: Text
Palavras-chave: Reproductive effort; Image analysis; Gametogenetic cycle; ELISA; Crassostrea gigas; Condition index.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4305.pdf

Techniques for delivery of arachidonic acid to Pacific oyster, Crassostrea gigas, spat
Provedor de dados: 5
Autores: Seguineau, Catherine; Soudant, P; Moal, Jeanne; Delaporte, Maryse; Miner, Philippe; Quere, Claudie; Samain, Jean-francois.
The present study tested two techniques for dietary supplementation of Crassostrea gigas spat with PUFA, such as arachidonic acid (AA). The first technique consisted of a preliminary enrichment and growth of an algal concentrate (T-ISO, Isochrysis sp.) with AA dissolved in an ethanol solution, the whole culture then being fed to the spat. This enrichment increased the AA weight percentage in T-ISO neutral and polar lipids from 0.6 to 22.4% and from 0.4 to 6.8%, respectively. The second delivery technique was direct addition separately of free AA dissolved in ethanol solution and algal concentrate (T-ISO + AA) to the spat-rearing tank. To test the efficiency of these delivery techniques, oyster spat were supplemented with AA-enriched T-ISO, T-ISO + AA, and...
Tipo: Text
Palavras-chave: Food supply; Arachidonic acid; Spat; Crassostrea gigas; Dietary.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-1094.pdf

The influence of dietary supplementation of arachidonic acid on prostaglandin production and oxidative stress in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Seguineau, Catherine; Racotta, Ilie; Palacios, Elena; Delaporte, Maryse; Moal, Jeanne; Soudant, Philippe.
In a previous study, dietary supplementation with arachidonic acid (ARA) to oysters Crassostrea gigas increased haemocyte numbers, phagocytosis, and production of reactive oxygen species level (ROS) by haemocytes (Delaporte et al., 2006). To assess if the observed stimulation of these cellular responses resulted from changes of ARA-related prostaglandin (PG) production, we analysed prostaglandin E2 metabolite (PGEM) content on the same oysters fed three levels of ARA. Dietary supply of polyunsaturated fatty acids (PUFA) could also induce an oxidative stress that could similarly increase cellular responses; therefore, two indicators of oxidative stress were analysed: peroxidation level and antioxidant defence status. Together the observed positive...
Tipo: Text
Palavras-chave: Prostaglandins; N-6 unsaturated fatty acids; Lipid peroxidation; Antioxidants; ROS production.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00040/15103/12785.pdf

Functional capacities of gill mitochondria in oyster Crassostrea gigas during an emersion/immersion tidal cycle
Provedor de dados: 5
Autores: Dudognon, Tony; Soudant, Philippe; Seguineau, Catherine; Quere, Claudie; Auffret, Michel; Kraffe, Edouard.
Sessile animals that live on the foreshore undergo tidal cycles, and have to face variations in physical and chemical parameters such as oxygen concentration. During emersion, availability of dissolved oxygen can be lowered for bivalves, which have only a small reserve of seawater inside their closed shell. Differences in oxygen concentration are thus expected to lead to modifications of the metabolism, including changes in mitochondrial activity. Previous studies investigated air exposure under extreme conditions, which do not always reflect environmental conditions these invertebrates have to cope with. In this study, oxidative capacities of gill mitochondria of the oyster Crassostrea gigas were studied during a tidal cycle period, by comparing oysters...
Tipo: Text
Palavras-chave: Mitochondria; Oxygen consumption; ATP production; Respiratory chain inhibitor; Crassostrea gigas.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26854/24981.pdf

Immune responses of phenoloxidase and superoxide dismutase in the manila clam Venerupis philippinarum challenged with Vibrio tapetis – Part I: Spatio-temporal evolution of enzymes’ activities post-infection
Provedor de dados: 5
Autores: Le Bris, Cedric; Richard, Gaelle; Paillard, Christine; Lambert, Christophe; Seguineau, Catherine; Gauthier, Olivier; Pernet, Fabrice; Guerard, Fabienne.
Manila clams, Venerupis philippinarum (Adams and Reeve, 1850), were experimentally challenged with two Vibrio tapetis strains: CECT4600T, the causative agent of Brown Ring Disease (BRD); and LP2 supposedly non-pathogenic in V. philippinarum. Changes in phenoloxidase (PO) and superoxide dismutase (SOD), two major enzymes involved in immunity, were studied in two tissues, the mantle and hemolymph for 30 days after infection in the extrapallial cavity. Bacterial infection in V. philippinarum resulted in modulation of PO and SOD activities that was both tissue- and time-dependent. A response at early times was detected in the mantle and was associated with significant increases in PO and SOD activities in LP2- and CECT4600T-challenged clams 36h post injection....
Tipo: Text
Palavras-chave: Venerupis philippinarum; Vibrio tapetis; Immunity; Phenoloxidase; Superoxide dismutase.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00221/33257/31733.pdf

Active and passive biomonitoring suggest metabolic adaptation in blue mussels (Mytilus spp.) chronically exposed to a moderate contamination in Brest harbor (France)
Provedor de dados: 5
Autores: Lacroix, Camille; Richard, Gaelle; Seguineau, Catherine; Guyomarch, Julien; Moraga, Dario; Auffret, Michel.
Brest harbor (Bay of Brest, Brittany, France) has a severe past of anthropogenic chemical contamination, but inputs tended to decrease, indicating a reassessment of its ecotoxicological status should be carried out. Here, native and caged mussels (Mytilus spp.) were used in combination to evaluate biological effects of chronic chemical contamination in Brest harbor. Polycyclic aromatic hydrocarbon (PAH) contamination was measured in mussel tissues as a proxy of harbor and urban pollution. Biochemical biomarkers of xenobiotic biotransformation, antioxidant defenses, generation of reducing equivalents, energy metabolism and oxidative damage were studied in both gills and digestive glands of native and caged mussels. In particular, activities of...
Tipo: Text
Palavras-chave: Marine biomonitoring; Chronic pollution; Blue mussel Mytilus spp.; Caging; Oxidative stress; Energetic metabolism; Bay of Brest.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00255/36654/35795.pdf

Delivery of riboflavin to larval and adult pacific oysters, Crassostrea gigas Thunberg by lipid spray beads
Provedor de dados: 5
Autores: Langdon, Cj; Seguineau, Catherine; Ponce, B; Moal, Jeanne; Samain, Jean-francois.
Lipid spray beads (SB) were prepared containing 13% w/w particulate riboflavin. Beads suspended in seawater lost 73% riboflavin after 24 h. Release of riboflavin from SE ingested by Pacific oyster (Crassostrea gigas) larvae was observed under epifluorescent light. Riboflavin concentrations in tissues of adult oysters fed on riboflavin-SB were significantly (SNK, P &lt; 0.05) greater than those of oysters fed on seawater-filled SE. Concentrations of riboflavin in oysters exposed to dissolved riboflavin were not significantly greater than those of oysters fed on seawater-filled SE: indicating that elevated riboflavin concentrations in oysters fed on riboflavin-SB were attributable to breakdown of ingested beads rather than uptake of dissolved riboflavin...
Tipo: Text
Palavras-chave: Spray beads; Lipid; Riboflavin; Oyster; Larvae; Crassostrea gigas.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00000/10493/9511.pdf

Impact of 20 : 4n-6 supplementation on the fatty acid composition and hemocyte parameters of the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Delaporte, Maryse; Soudant, Philippe; Moal, Jeanne; Giudicelli, Emilie; Lambert, Christophe; Seguineau, Catherine; Samain, Jean-francois.
Arachidonic acid (20:4n-6, ArA) and its eicosanoid metabolites have been demonstrated to be implicated in immune functions of vertebrates, fish, and insects. Thus, the aim of this study was to assess the impact of ArA supplementation on the FA composition and hemocyte parameters of oysters Crassostrea gigas. Oyster dietary conditioning consisted of direct addition of ArA solutions at a dose of 0, 0.25, or 0.41 mu g ArA per mL of seawater into tanks in the presence or absence of T-Iso algae. Results showed significant incorporation of ArA into gill polar lipids when administered with algae (up to 19.7%) or without algae (up to 12.1%). ArA supplementation led to an increase in hemocyte numbers, phagocytosis, and production of reactive oxygen species by...
Tipo: Text
Palavras-chave: Hemocyte parameters; Oyster immunity; Arachidonic Acid; Poly unsaturated fatty acids; Nutrition; Bivalve; Crassostrea gigas.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1876.pdf