Consulta: creatorFacets:"Gagnaire, Beatrice"
Registros recuperados: 37
Data/hora: 06/06/2024 19:06:50

Pollutant effects on Pacific oyster, Crassostrea gigas (Thunberg), hemocytes: Screening of 23 molecules using flow cytometry
Provedor de dados: 5
Autores: 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

Characterization of summer mortalities of C. gigas oyster in France in relation to environmental parameters
Provedor de dados: 5
Autores: 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

Diploid and triploid Pacific oysters, Crassostrea gigas (Thunberg), reared at two heights above sediment in Marennes-Oleron Basin, France: Difference in mortality, sexual maturation and hemocyte parameters
Provedor de dados: 5
Autores: 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

Défi MOREST - Mortalités estivales de l'huître creuse Crassostrea gigas - Caractérisation des facteurs de risques associés aux mortalités estivales - Synthèse du thème 5 - Risque associé aux pathogènes. (La Rochelle 14-15 mars 2006)
Provedor de dados: 5
Autores: 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
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00304/41535/40743.pdf

Impact of diuron on aneuploidy and hemocyte parameters in Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Bonnard, Marc; Gagnaire, Beatrice; Renault, Tristan; Lapegue, Sylvie.
Diuron is a substituted urea herbicide used for agricultural and nonagricultural weed control. Its widespread use and relatively slow breakdown led us to analyze its influence on aneuploidy level (lowered chromosome number in a percentage of somatic cells) and hemocyte parameters in Pacific oysters, Crassostrea gigas. Adult oysters were subjected to two diuron concentrations (300 ng L-1 and 3 mu g L-1) for 11 weeks. Significantly higher aneuploidy level was observed in diuron-treated oysters compared with the control. Furthermore, the observed impact on aneuploidy persisted to the next generation as offspring exhibited significantly higher aneuploidy levels when their parents had been exposed to diuron. Significant increases in hemocyte parameters (cell...
Tipo: Text
Palavras-chave: Diuron; Herbicide impact; Cytometry; Hemocyte; Aneuploidy; Crassostrea gigas.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2178.pdf

Environment and immunomodulation : effects of the soluble fraction of Norwegian heavy fuel on the immune system of Pacifc oyster, Crassostrea gigas
Provedor de dados: 5
Autores: 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

Effets d'un mélange de pesticides sur les hémocytes d'huître creuse, Crassostrea gigas.
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Geret, Florence; Haure, Joel; Martin, Jean-louis; Burgeot, Thierry; Thomas-guyon, Hélène; Renault, Tristan.
Shellfish industry is often realised in estuarine areas, subjected to pollutions due to agricultural activities. The harmful effects of pesticides on animals inhabiting these estuarine zones are poorly documented. Bivalve molluscs represent an interesting model because they are sedentary and they filter water intensively. Effects of pesticides on haemocytes functions were tested in Pacific oyster, Crassostrea gigas and analysed by flow cytometry. A combination of pesticide at environmental concentrations was tested in vivo. Animals used corresponded to two genetically selected populations produced in hatchery.
Tipo: Text
Palavras-chave: Haemocytes; Flow cytometry; Pesticides; Crassostrea gigas.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-924.pdf

Study of interactions between flat oyster, Ostrea edulis, and the parasite Bonamia ostreae using flow cytometry and suppression subtractrive hybridization (SSH)
Provedor de dados: 5
Autores: Morga, Benjamin; Arzul, Isabelle; Faury, Nicole; Gagnaire, Beatrice; Chollet, Bruno; Renault, Tristan.
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. Control of bonamiosis requires a good knowledge of the parasite life cycle including host-parasite interactions. In this study, we investigated interactions between parasites and haemocytes by flow cytometry and Suppression Subtractive Hybridization (SSH). In both approaches, analyses were performed after 2 hours of contact between haemocytes and parasites purified from highly infected flat oysters. Flow cytometry analyses consisted in testing haemocyte activities including esterase activities, reactive oxygen species (ROS) production and phagocytosis after contact with live parasites and parasites inactivated by...
Tipo: Text
Palavras-chave: SSH; Suppression subtractive hybridization; Cytometry; Bonamia ostreae; Parasite; Ostrea edulis; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3367.pdf

In vitro effects of cadmium and mercury on Pacific oyster, Crassostrea gigas (Thunberg), haemocytes
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Thomas Guyon, H; Renault, Tristan.
In the past decades. shellfish culture has developed in a significant way around the world. However, culture areas are Often Subject to recurring anthropic pollution. The recrudescent presence of industrial wastes is a source of heavy metals and results ill pollutant transfer towards the aquatic environment in estuarine areas. Because of their mode of life. bivalves. including Mussels and oysters. are suggested as ideal indicator organisms. The development of techniques allowing the analysis of the effects of Pollutants on bivalve biology may lead to the monitoring of pollutant transfer in estuarine areas. in this context. the effects of cadmium and mercury On defence mechanisms were analysed in Pacific oysters. Crassostrea gigas. Pollutant effects were...
Tipo: Text
Palavras-chave: Toxicity; Cellular activities; Phenoloxidase; Mercury; Cadmium; Flow cytometry; Haemocytes; Crassostrea gigas.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-691.pdf

Etude des intéractions entre le parasite Bonamia ostreae et son hôte, huître plate Ostrea edulis in vitro
Provedor de dados: 5
Autores: 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

Study of atrazine effects on Pacific oyster, Crassostrea gigas, haemocytes
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Renault, Tristan; Bouilly, Karine; Lapegue, Sylvie; Thomas-guyon, H.
Shellfish farming is an important economic activity around the world. This activity often takes place in areas subjected to various recurring pollutions. The recrudescent use of herbicides in agriculture including atrazine implies pollutant transfer towards aquatic environment in estuarine areas. Harmful effects of such substances on animals in marine environment, particularly on cultured bivalves, are poorly documented. Bivalve molluscs such as mussels and oysters have been postulated as ideal indicator organisms because of their way of life. They filter large volumes of seawater and may therefore accumulate and concentrate eontaJ.11inants within their tissues. Moreover, development of techniques allowing effect analysis of such compounds on bivalve...
Tipo: Text
Palavras-chave: Crassostrea gigas; Haemocytes; Flow cytometry; Atrazine; Cellular activities; Toxicity.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-2827.pdf

Effects of temperature and salinity on the survival of Bonamia ostreae parasite infecting falt oyster Ostrea edulis in sea water
Provedor de dados: 5
Autores: 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

Comparison of hemocyte parameters in the pericardial cavity and the adductor muscle sinus in the Pacific oyster, Crassostrea gigas using two types of flow cytometers
Provedor de dados: 5
Autores: 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

Effect of environmental and nutritive conditionings on defense mechanisms of oyster Crassostrea gigas during an annual cycle
Provedor de dados: 5
Autores: 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

Effects of cadmium on aneuploidy and hemocyte parameters in the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: 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

Etude pluridiciplinaire de la DYNAmique des MOrtalités estivales dans le bassin de Marennes- Oléron : Dynamique des mortalités en relation avec la reproduction in situ et la température - Suivi de paramètres hémocytaires - Synergie écologie côtière et activité hémocytaire
Provedor de dados: 5
Autores: Renault, Tristan; Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel; Seugnet, Jean-luc; Gagnaire, Beatrice; Kerdudou, Nolwenn.
Massive abnormal mortalities of flat oysters Crassostrea during the summer period are nothing new, and such episodes have been described in scientific literature for about forty years. Numerous studies demonstrate that there is not one single identified cause to this phenomenon and that it is, on the contrary, a combination of different parameters. This program proposes a multidisciplinary approach to the problem of summer mortality of C. gigas in which the working hypothesis is that these mortalities result from the interaction of three parameters: environment, host and pathogens. As a consequence, this program gathers all the necessary competences for the study of these interactions: competences in genetics, physiology, immunology, ecotoxicology,...
Tipo: Text
Palavras-chave: Marennes Oléron; Activité hémoctyaire; Synergie écologie côtière; Pathologie; Paramètres hémocytaires; Physiologie; Paramètres; Reproduction; Mortalités; Crassostrea gigas; Huîtres.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/acte-3404.pdf

Isolation and primary culture of gill and digestive gland cells from the common mussel Mytilus edulis
Provedor de dados: 5
Autores: 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

Recherche d'effets biologiques de l'atrazine sur hémocytes d'huître creuse, Crassostrea gigas, in vivo et in vitro
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Thomas-guyon, Hélène; Lapegue, Sylvie; Bouilly, Karine; Renault, Tristan.
In the last decades, shellfish farming and in particular ostreiculture have developed in a significant way in France. Marennes-Oleron (Charente-Maritime) basin is the first French producer of oysters. But this area is also subjected to many recurring pollution, brought mainly by the Charente river.  The recrudescence using of herbicides in agriculture including atrazine implies the transfer towards the aquatic environment of new pollutants in estuarine areas. Moreover industrial rejections bring many heavy metals in these same estuarine areas.  It is appropriate of wondering on harmful effects of all these pollutants on the animals living in these areas, particularly oysters.  Bivalve molluscs have been postulated as ideal indicator organisms because of...
Tipo: Text
Palavras-chave: Atrazine; Flow cytometry; Haemocytes; Crassostrea gigas; Atrazine; Cytométrie de flux; Hémocytes; Crassostrea gigas.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-834.pdf

Genetically based resistance to summer mortality in the Pacific oyster (Crassostrea gigas) and its relationship with physiological, immunological characteristics and infection processes
Provedor de dados: 5
Autores: Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Haure, Joel; Bedier, Edouard; Ropert, Michel; Moal, Jeanne; Huvet, Arnaud; Bacca, Helene; Van Wormhoudt, A; Delaporte, Maryse; Costil, K; Pouvreau, Stephane; Lambert, Christian; Boulo, Viviane; Soudant, Philippe; Nicolas, Jean-louis; Leroux, Frederique; Renault, Tristan; Gagnaire, Beatrice; Geret, Florence; Boutet, Isabelle; Burgeot, Thierry; Boudry, Pierre.
Summer mortality of Pacific oysters is known in several countries. However no specific pathogen has been systematically associated with this phenomenon. A complex combination of environmental and biological parameters has been suggested as the cause and is now starting to be identified. A high genetic basis was found for survival in oysters when a first generation (G1) was tested in three sites during summer. This paper presents a synthesis on physiological characteristics of two selected groups ('R' and 'S', from families selected for resistance and susceptibility to summer mortality respectively), of the second and third generations. R and S showed improvement or reduction of survival compared with the control in both field and laboratory trials...
Tipo: Text
Palavras-chave: ROS; Temperature; Stress; Hemocytes; Reproduction; Genetic selection; Resistant oyster; Crassostrea gigas; Pacific Oyster; Summer mortality.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2809.pdf

Combination of a pesticide exposure and a bacterial challenge: In vivo effects on immune response of Pacific oyster, Crassostrea gigas (Thunberg)
Provedor de dados: 5
Autores: 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

Effects of 16 pure hydrocarbons and two oils on haemocyte and haemolymphatic parameters in the Pacific oyster, Crassostrea gigas (Thunberg)
Provedor de dados: 5
Autores: 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

Demonstration of a true phenoloxidase activity and activation of a ProPO cascade in Pacific oyster, Crassostrea gigas (Thunberg) in vitro
Provedor de dados: 5
Autores: 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

Etude de l'impact de micropolluants sur les capacités immunitaires de l'huître creuse, Crassostrea gigas, in vivo et in vitro
Provedor de dados: 5
Autores: 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

Environnement et immunomodulation : étude d'activités hémocytaires chez l'huître creuse, Crassostrea gigas
Provedor de dados: 5
Autores: 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

Environmental stress in the pacific oyster Crassostrea gigas during gametogenesis : role of herbicides?
Provedor de dados: 5
Autores: Burgeot, Thierry; Quirion, Sophie; Quiniou, Francoise; Knoery, Joel; Soletchnik, Patrick; Gagnaire, Beatrice; Renault, Tristan; Osada, M.; Geret, F.; Communal, P. Y.; Jadas-hecart, A.; Gagne, F.
In the Atlantic French coast, significant mortalities were observed in oyster communities during gametogenesis. These deaths possibly result from the cumulative effects of various stressors such as seasonal temperature variations, pesticide application and the release of contaminants from the resuspension of sediments. A field survey, based on aquaculture conditions at 15 and 70 cm from the sediment bed with genetically-resistant (R) and -sensitive (S) lines, showed a stress condition. Significant weight loss was observed during May 14th through June 10th for both R and S lines. On one hand, the levels of the egg yolk vitellin in females were decreased at May 14th for both R and S lines.  On the other hand, a significant increase in vitellin production was...
Tipo: Text
Palavras-chave: Mortalities; Herbicides; Sediment; Biomarkers; Gametogenesis; Crassostrea gigas; Pacific oysters.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3384.pdf

Environment and immunomodulation : effects of the soluble fraction of Norwegian heavy fuel on the immune system of Sea bass, Dicentrarchus labrax
Provedor de dados: 5
Autores: 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

Effects of depleted uranium on immune parameters of zebrafish, Danio rerio, measured by flow cytometry
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Bado-nilles, A.; Betoulle, S.; Sanchez, Wilfried.
Tipo: Text
Palavras-chave: Depleted uranium; Zebrafish; Flow cytometry.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00500/61182/64702.pdf

A flow cytometric approach to study intracellular-free Ca2+ in Crassostrea gigas haemocytes
Provedor de dados: 5
Autores: 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

Etude des intéractions entre le parasite Bonamia ostreae et son hôte, huître plate Ostrea edulis in vitro (Diaporama)
Provedor de dados: 5
Autores: 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: Intéraction; Hémocytes; Ostrea edulis; Bonamia ostreae; Parasitologie.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3366.pdf

Etude des effets de polluants sur les paramètres hémocytaires de l'huître creuse, Crassostrea gigas - Interactions entre environnement, mécanismes de défense et maladies infectieuses
Provedor de dados: 5
Autores: Gagnaire, Beatrice.
Shellfish industry is mostly realized in estuary zones, which are subjected to pollutions due to anthropic activities. The harmful effects of pollutants on animals inhabiting these estuarine zones are poorly known. Among these animals, Pacific oyster, Crassostrea gigas, may represent a model because they are sedentary and they filter water intensively. Among all physiological functions possibly disturbed by pollutants, defence mechanisms are poorly studied in bivalves. Moreover, animals presenting impaired defence mechanisms may be more sensitive to infectious diseases. In this context, effects of pollutants on hemocyte functions and on sensitiveness to diseases were tested in C. gigas. After adjusting the protocols for the monitoring of hemocyte...
Tipo: Text
Palavras-chave: Real time PCR; Flow cytometry; Pesticides; Pollutants; Phagocytosis; Hemocytes; Crassostrea gigas; Pacific oyster; Pathology; Immunotoxicology; PCR en temps réel; Cytométrie de flux; Pesticides; Polluants; Phagocytose; Hémocytes; Crassostrea gigas; Huître creuse; Pathologie; Immunotoxicologie.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-730.pdf

Flow cytometry to measure impact of temperature and salinity on the survival of Bonamia ostreae, parasite infecting flat oyster Ostrea edulis, in seawater
Provedor de dados: 5
Autores: 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 1979&amp;#305; 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

Effect of in vivo pesticide exposure and injection of bacteria on immune gene expression in the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: 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

Etude in vivo et in vitro des effets du mercure sur la réponse hémocytaire de l'huître creuse, Crassostrea gigas : développement de techniques évaluant les impacts de la pollution estuarienne
Provedor de dados: 5
Autores: Gagnaire, Beatrice; Renault, Tristan; Thomas-guyon, Hélène.
In the last decades, shellfish industry represents an important economic activity in France and particularly in Charente-Maritime. Marennes-Oleron basin is the first French area of oyster production, especially Pacific  oyster, Crassostrea gigas. But this area is also subjected to many pollution due to anthropic activities. Industrial wastes are sources of mercury pollution in the Charente river. The harmful effects of such contaminants on animals inhabiting these estuarine zones are poorly known, although many studies begin to be developed. Most of these studies use bivalve molluscs as biological indicators : these animals can bioaccumulate pollutants within their tissues by filtration. Moreover, they are sedentary so they cannot escape in the case of a...
Tipo: Text
Palavras-chave: Flow cytometry; Haemocytes; Mercury; Crassostrea gigas; Cytométrie de flux; Hémocytes; Mercure; Crassostrea gigas.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/acte-830.pdf

Analysis of hemocyte parameters in Pacific oysters, Crassostrea gigas, reared in the field — Comparison of hatchery diploids and diploids from natural beds
Provedor de dados: 5
Autores: 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

Effects of temperature and salinity on haemocyte activities of the Pacific oyster, Crassostrea gigas (Thunberg)
Provedor de dados: 5
Autores: 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

Caractérisation des facteurs de risques associés au mortalités estivales - Synthèse du thème 3 - Risque associé au stress environnemental - 2002-2005
Provedor de dados: 5
Autores: 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
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00304/41538/40746.pdf

Effects of temperature and salinity on the survival of Bonamia ostreae, a parasite infecting flat oysters Ostrea edulis
Provedor de dados: 5
Autores: 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 l–1. 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