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| Registros recuperados: 37 | |
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| Bouilly, Karine; Gagnaire, Beatrice; Bonnard, Marc; Thomas-guyon, Helene; Renault, Tristan; Miramand, Pierre; Lapegue, Sylvie. |
| Pacific oysters, Crassostrea gigas, are commonly reared in estuaries where they are exposed to anthropogenic pollution. Much research has been made on the toxicity of cadmium to aquatic organisms because the compound recurrently contaminates their environment. Our study examined the influence of cadmium on aneuploidy level (lowered chromosome number in a percentage of somatic cells) and hemocyte parameters in C. gigas at different stages of life. Adults and juveniles were exposed to two different concentrations of cadmium. The first concentration applied was equivalent to a peak value found in Marennes-Oleron bay (Charente-Maritime, France; 50 ng L-1) and the second was 10 times higher (500 ng L-1). Exposure to 50 ng L-1 cadmium caused a significant... |
| Tipo: Text |
Palavras-chave: Phenoloxidase; Flow cytometry; Hemocytes; Aneuploidy; Crassostrea gigas; Cadmium. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1687.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; 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 |
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| Gagnaire, Beatrice. |
| La conchyliculture et notamment l'ostréiculture se sont beaucoup développées en France dans les dernières décennies. Le bassin de Marennes-Oléron (Charente-Maritime) est le premier bassin français producteur d'huîtres. Mais cette zone est également soumise à de nombreuses pollution récurrentes, apportées principalement par la Charente. La recrudescence de l'utilisation d'herbicides en agriculture tels que l'atrazine implique le transfert vers le milieu aquatique de nouveaux polluants dans les zones d'estuaires. De plus, les rejets industriels apportent de nombreux métaux lourds dans ces mêmes zones d'estuaire. Il convient de s'interroger sur les effets néfastes de tous ces polluants sur les animaux vivant dans ces zones, tout particulièrement les huîtres,... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Hémocytes; Cytométrie de flux; Métaux lourds; Atrazine; Phénoloxydase. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00032/14337/11620.pdf |
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| Gagnaire, Beatrice. |
| Depuis plusieurs décennies, l'ostréiculture est une activité économique importante en France et particulièrement en Charente-Maritime. En effet, le bassin de Marennes-Oléron est le premier bassin français producteur d'huîtres, notamment l'huître creuse, Crassostrea gigas. Cependant, cette zone est soumise à de nombreuses pollutions de nature anthropique. Les industries rejettent du mercure en quantité importante dans la Charente. De plus, du fait des courant locaux, le cadmium, présent en grande quantité dans le bassin de la Gironde, est également retrouvé dans le bassin de Marennes-Oléron. Les effets de ces polluants sur les animaux présents dans ces zones d'estuaires sont encore peu connus, bien que de nombreuses études soient en cours de développement.... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Hémocytes; Cytométrie de flux; Métaux lourds; Phénoloxydase; Conditions environnementales; Origine génétique. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00032/14344/11628.pdf |
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| Gagnaire, Beatrice; Duchemin, M; Auffret, Mathieu; Thomas-guyon, Helene; Renault, Tristan. |
| Parameters of hemocyte populations have been considered as relevant indicators of bivalve health and are currently used in immunotoxicological studies. Hemocytes in hemolymph can be collected by puncturing either the pericardial cavity or the adductor muscle sinus with a syringe. Flow cytometry is a methodological approach that is increasingly being used in laboratories for the study of hemocyte parameters in aquatic invertebrates. However, various protocols for hemocyte processing in laboratories equipped with different types of cytometers have been published. In this context, two flow cytometers ( EPICS XL4 (R), Beckman Coulter and FacsCalibur (R), Becton Dickinson) and two sites of hemocyte collection ( pericardial cavity and adductor muscle sinus) were... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Phagocytosis; Hemocytes; Flow cytometry. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3898.pdf |
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| Gagnaire, Beatrice; Soletchnik, Patrick; Faury, Nicole; Kerdudou, Nolwenn; Le Moine, Olivier; Renault, Tristan. |
| Internal defence mechanisms of bivalves include the hemocytes which assume several functions. Relationships exist between environmental factors, physiological state of oysters, defence system and pathogens. Hatchery oysters are more and more produced and reared in the field. The characteristics and particularly the defence system of these animals are poorly documented. In this context, two field trials were carried out from May to September 2002 and from April to July 2003 in order to monitor hemocyte parameters of diploid oysters from natural beds and hatchery-produced diploid oysters using flow cytometry. Several hemocyte parameters (cell mortality, granulocyte percentage, phagocytosis, esterase and peroxidase activities) were monitored. For both oyster... |
| Tipo: Text |
Palavras-chave: Hatchery; Natural beds; Diploids; Flow cytometry; Peroxidase activity; Esterase activity; Phagocytosis; Hemocytes; Crassostrea gigas; Pacific oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3119.pdf |
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| Faucet, Jerome; Maurice, Manuelle; Gagnaire, Beatrice; Renault, Tristan; Burgeot, Thierry. |
| As the marine mussel Mytilus edulis is commonly used as a sentinel species, it would be useful to develop a primary culture of the target organs most often in contact with the marine environment. This study reports an improved method for dissociating the digestive gland and gills of M. edulis and considers the effect of mussel storage on cell viability and functionality before culture initiation. Viability and enzymatic activities such as those of esterase and peroxidase were monitored by flow cytometry, a sensitive, objective technique allowing large volumes of cells to be counted within a short time. A primary culture of digestive gland showed more than 75% viability after 72 h. Mussels were maintained in an aquarium containing clean, oxygenated seawater... |
| Tipo: Text |
Palavras-chave: Mytilus edulis; Gill; Flow cytometry; Digestive gland; Cell culture. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-936.pdf |
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| Hellio, Claire; Bado Nilles, Anne; Gagnaire, Beatrice; Renault, Tristan; Thomas-guyon, Helene. |
| The prophenoloxidase (ProPO) system is the origin of melanin production and is considered to be an innate defence mechanism in invertebrates. In different bivalve species, phenoloxidase (PO) is present in the haemolymph as an inactive form of ProPO. The present study focuses on the Pacific adult oyster, Crassostrea gigas, an economically important bivalve species along French coasts. The results indicate that many factors may inhibit the PO-like activity. These include: phenylthiourea (PTU), sodium diethylthiocarbamate (DETC), beta-mercaptoethanol and tropolone, which repressed the spontaneous PO activity. The activation of PO-like activity in C. gigas acellular fraction by lipopolysaccharide (LPS) involved participation of other factors, including at... |
| Tipo: Text |
Palavras-chave: Prophenoloxidase; Phenoloxidase; Oyster; Immunity; Defence; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2926.pdf |
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| Delaporte, Maryse; Moal, Jeanne; Soudant, Philippe; Lambert, Christophe; Pouvreau, Stephane; Enriquez, Martha; Degremont, Lionel; Soletchnik, Patrick; Gagnaire, Beatrice; Ropert, Michel. |
| In the frame of MOREST project, a common biological material, resulting of a mixture of different families produced in experimental hatchery, was reared in two different environmental fields : Normandy and Charente. Concomitantly, a pool was conditioned at the Ifremer Argenton hatchery with three different algae levels : 4%, 8% and 12% of algal dry weight per oyster dry weight. During the experiments, five immune parameters were studied in parallel with survival rate and reproductive status (stages and intensity). Site location, seasonal variations and experimental diet level clearly influenced oyster immune parameters. Haemocyte counts were higher for oysters reared in Normandy than those reared in Charente and in hatchery. Granulocyte percentage was... |
| Tipo: Text |
Palavras-chave: Defense mechanisms; Nutrition; Seasonal variations; Physiology; Crassostrea gigas; Pacific oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3500.pdf |
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| Nicolas, Jean-louis; Renault, Tristan; Gagnaire, Beatrice; Garcia, Celine; Le Roux, F; Miossec, Laurence; Pepin, Jean-francois; Saulnier, Denis. |
| L'un des objectifs principaux des travaux en pathologie des mollusques est d'identifier et d'étudier des agents infectieux capables d'induire des maladies et des mortalités chez les coquillages, en particulier, chez I'huître creuse, Crassostrea gigas, espèce principalement exploitée en France. Ces travaux semblent d'autant plus indispensables qu'il n'existait pas, jusqu'à ces dernières années, de maladies identifiées chez I'huître creuse en Europe excepté le virus herpès suspecté dès 1995 de provoquer des mortalités de naissain (Renault et al, 1995). Les principales maladies des espèces proches sont dues à des parasites comme Haplosporidium nelsoni (Ford et Heskin, 1987) et Perkinsus marinus Olivier et al, 1 998) pour Crassostrea virginica, Marteilia... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41535/40743.pdf |
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| Arzul, Isabelle; Bond, Celine; Gagnaire, Beatrice; Chollet, Bruno; Morga, Benjamin; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan. |
| Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. The parasite has been described in different ecosystems from estuaries to open sea and no clear correlations could be demonstrated between the development of the disease and environmental parameters such as temperature or salinity. The parasite life cycle, including its survival outside the host is not completely known. Nevertheless, the infection can be directly transmitted by cohabitation between infected and non infected oysters suggesting that the parasite does not need intermediate host to complete its cycle. In the present study, the impact of temperature and salinity on the survival of purified parasites... |
| Tipo: Text |
Palavras-chave: Effects; Temperarature; Salinity; Bonamia ostreae; Parasite; Pathology; Flat oyster; Ostrea edulis; Oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3375.pdf |
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| Arzul, Isabelle; Bond, Celine; Gagnaire, Beatrice; Morga, Benjamin; Chollet, Bruno; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan. |
| Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting the flat oyster, Ostrea edulis. After its first description in June 1979ı in Brittany, the parasite rapidly spread to all French oyster farming areas and in other European countries through transfers of live molluscs. The parasite has been described in different ecosystems from estuaries to open sea and no clear correlations could he demonstrated between the disease development and environmental parameters like temperature or salinity. The infection can he directly transmitted by cohabitation between infected and non infected oysters. Nevertheless, the parasite life cycle, including its survival outside the host, is not completely... |
| Tipo: Text |
Palavras-chave: Impact; Salinity; Temperature; Flow cytometry; Bonamia ostreae; Parasite; Ostrea edulis; Oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3372.pdf |
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| Burgeot, Thierry; Gagnaire, Beatrice; Renault, Tristan; Haure, Joel; Moraga, D.; David, E.; Boutet, L.; Sauriau, P.g.; Malet, Nathalie; Bouchet, V.; Lapegue, Sylvie; Bouilly, Karine; Le Moullac, Gilles; Arzul, Genevieve; Knoery, Joel; Quiniou, Francoise; Bacher, Cedric; Soletchnik, Patrick. |
| Les mortalités d'huîtres observées sur les côtes françaises apparaissent principalement à proximité du sédiment et pendant la gamétogenèse. Les interactions de facteurs environnementaux sur les écosystèmes conchylicoles comme la température, les apports des bassins versants et le compartiment sédimentaire illustrent un risque de mortalité lié à différentes sources de stress (Thème 1). Les variations de la qualité de la ressource trophique pendant l'effort de gamétogenèse favorise une baisse de l'énergie disponible (Thème 2) et contraint l'organisme fragilisé à fournir un effort d'adaptation (Fent 2004). L'apparition d'un stress pendant cette période sensible des huîtres pourrait constituer un facteur aggravant de mortalité. L'objectif de cette étude est... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41538/40746.pdf |
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| Bado-nilles, Anne; Quentin, Claire; Le Floch, Stéphane; Arzel, Jacqueline; Auffret, Michel; Gagnaire, Beatrice; Renault, Tristan; Thomas-guyon, Hélène. |
| Estuaries and coastal areas are often subjected to much pollution, including pesticides and polycyclic aromatic hydrocarbons (PAHs) produced by anthropic activities. Bay of Marennes-Oléron is an estuarine coastal zone in which there is a high level of aquacultural production and this has adverse effects in aquatic organisms. In fact, PAHs, which are widely spread throughout aquatic ecosystems, have a low polarity and so there is a clear tendency to bioaccumulate in marine organisms (1). The harmful effects of such contaminants on the organism's immune system, leading to a decreased resistance to pathogens, is a relatively new area of research and it still poorly understood. The aim of the present work was to detect the impact in vivo of PAHs on the immune... |
| Tipo: Text |
Palavras-chave: PaHs; Fish; Contamination; Dicentrarchus labrax. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3427.pdf |
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| Morga, Benjamin; Arzul, Isabelle; Chollet, Bruno; Gagnaire, Beatrice; Renault, Tristan. |
| Bonamiosis is a disease affecting the flat oyster Ostrea edulis and caused by the protozoa parasite Bonamia ostreae, which is affiliated to the haplosporidia order and the cercozoa phylum. This parasite is mainly intracellular, infecting haemocytes, circulating cells playing an important role in the oyster's defence mechanisms. Even though the parasite's cycle has not been completely understood yet, direct infection from infected oysters to healthy oysters is possible. This leads us to think that there is no intermediary host in the cycle. Very little data on the parasite's infection mechanisms or the host's defence mechanisms is available. In order to better comprehend the Bonamia ostreae / host interaction, some flat oyster's haemocytes have been put in... |
| Tipo: Text |
Palavras-chave: Hémocytes; Ostrea edulis; Bonamia ostreae; Parasite; Huîtres. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3368.pdf |
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| Aton, Emilie; Renault, Tristan; Gagnaire, Beatrice; Thomas Guyon, Hélène; Cognard, C; Imbert, N. |
| Bivalve haemocytes are essential in defence mechanisms including phagocytosis. They also produce molecules including hydrolytic enzymes and antimicrobial peptides that contribute to pathogen destruction. Although haemocyte activities have been extensively studied, relatively little is known about the intracellular signalling pathways that are evoked during haemocyte activation and especially the role of calcium. Flow cytometry has been used for the first time to define the effect of cell incubation in haemolymph and artificial sea water (ASW) on Pacific oyster, Crassostrea gigas, haemocytes. Cell viability, enzymatic activities (esterases and amino peptidases), phagocytosis and granulocyte percentage were analysed. Viability and some activities were... |
| Tipo: Text |
Palavras-chave: Cellular activities; Fluo 3/AM; Calcium; Flow cytometry; Haemocytes; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-935.pdf |
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| Registros recuperados: 37 | |
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