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| Registros recuperados: 37 | |
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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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| 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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| 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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| 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 |
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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; 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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| 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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| 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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| Gagnaire, Beatrice; Soletchnik, Patrick; Madec, Patrick; Geairon, Philippe; Le Moine, Olivier; Renault, Tristan. |
| Summer mortality is an important economic concern for the Pacific oyster, Crassostrea gigas, industry all over the world and particularly in France. Outbreaks appear when oysters are in gonadal maturation. Bivalve defence mechanisms against pathogen invasion are assumed by circulating cells, the hemocytes. A field experiment was conducted in the Marennes-Oleron Basin (Charente-Maritime, France) in order to monitor hemocyte parameters, gametogenesis and mortality rates among C. gigas during 7 months from March to September 2002. Diploid (from natural bed and from hatchery) and triploid oysters were placed at 15 cm or 70 cm above sediment at Marennes-Oleron Basin. Triploid animals were included because they are considered as sterile animals. Mortality rates... |
| Tipo: Text |
Palavras-chave: Sexual maturation; Summer mortality; Triploids; Diploids; Flow cytometry; Hemocyte activities; Crassostrea gigas; Pacific oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2923.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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| 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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| Bado Nilles, A; Gagnaire, Beatrice; Thomas-guyon, Helene; Le Floch, S; Renault, Tristan. |
| The in vitro effects of polycyclic aromatic hydrocarbons (PAHs) on haemocyte and haemolymphatic parameters of the Pacific oyster, Crassostrea gigas, were tested using field concentrations (10(-7) and 10(-9) mg mL(-1)) observed in the Marennes-Oleron Basin (Charente-Maritime, France) and high concentrations (10(-3) and 10(-5) mg mL(-1)) observed during oil spills. As a first step, the effects of pollutants, after a 24 h contamination period, were monitored on individual and pooled haemolymph samples and similar results were observed for both sample types. In a second step, haemolymphs from 45 oysters were withdrawn and pooled. Eighteen pollutants were tested in vitro after a 4 and 24 h contamination period and 10 of them showed significant modulations of... |
| Tipo: Text |
Palavras-chave: Toxicity; PAHs; Pacific oyster; Spectrophotometry; Flow cytometry; Haemocyte activity. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4696.pdf |
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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; Frouin, Heloise; Moreau, Kevin; Thomas Guyon, Helene; Renault, Tristan. |
| The Pacific oyster, Crassostrea gigas, is extensively cultivated and represents an important economic activity. Oysters are reared in estuarine areas, subjected to various biotic and abiotic factors. One of the limiting factors in aquaculture is mortality outbreaks, which may limit oyster production, and the causes of these outbreaks are not completely understood. In this context, the effects of temperature and salinity on Pacific oyster, C. gigas, haemocytes, were studied. Haemocytes are the invertebrate blood cells and thus have been shown to be involved in defence mechanisms. Flow cytometry was used for monitoring several haemocyte parameters. An increase of temperature induced an increase of haemocyte mortality, in both in vitro and in vivo... |
| Tipo: Text |
Palavras-chave: Cellular activity; Flow cytometry; Salinity; Temperature; Haemocyte; Crassostrea gigas; Pacific oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-934.pdf |
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| Arzul, Isabelle; Gagnaire, Beatrice; Bond, Celine; 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 the flat oyster Ostrea edulis. The parasite has been described in various ecosystems from estuaries to open sea, but no clear correlation has yet been demonstrated between disease development and environmental parameters. In this study, the effect of temperature and salinity on the survival of purified parasites maintained in vitro in seawater was investigated by flow cytometry. Purified parasites were incubated in various seawater media (artificial seawater, natural seawater, seabed borewater) at various temperatures (4, 15 and 25°C) and subjected to a range of salinities from 5 to 45 g l1. Parasites were collected after 12, 24 and 48 h of... |
| Tipo: Text |
Palavras-chave: Salinity tolerance; Temperature tolerance; Cell viability; In vitro assays; Flow cytometry; Bonamia ostreae. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6443.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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| Bado-nilles, Anne; Auffret, Michel; Quentel, Claire; Le Floch, Stéphane; Arzel, Jacqueline; 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; Contamination; Crassostrea gigas; Oyster. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3428.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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| Registros recuperados: 37 | |
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