Consulta: creatorFacets:"Lambert, Christophe"
Registros recuperados: 52
Data/hora: 12/06/2024 07:03:48

Effects of extracellular products from the pathogenic Vibrio aestuarianus strain 01/32 on lethality and cellular immune responses of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Labreuche, Yannick; Soudant, Philippe; Goncalves, Madeleine; Lambert, Christophe; Nicolas, Jean-louis.
Vibrio aestuarianus strain 01/32 was previously shown to be pathogenic to Crassostrea gigas juveniles. To investigate virulence mechanisms of this pathogen, we studied the toxicity to oysters of its extracellular products (ECPs). ECPs displayed lethality to animals, with a LD50 value of 3.3 mu g/g body weight. To determine the oyster cellular immune responses induced by these ECPs, we further examined in vitro their effects on C. gigas hemocytes, using flow cytometric-based hemocyte assays. Treatment of hemolymph with ECPs caused a significant inhibition of hemocyte phagocytosis and adhesive capabilities. In contrast, the pathway of reactive oxygen species production was enhanced by higher ECP concentrations. Exposure of hemocytes to live bacteria induced...
Tipo: Text
Palavras-chave: Vibrio aestuarianus; ECPs; Crassostrea gigas; ROS production; Adhesion; Phagocytosis; Flow cytometry; Bivalve immunity.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1035.pdf

Effects of Alexandrium minutum exposure upon physiological and hematological variables of diploid and triploid oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Gueguen, Marielle; Moal, Jeanne; Palacios, Elena; Lassus, Patrick; Soudant, Philippe.
The effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon physiological parameters of the Pacific oyster, Crassostrea gigas, were assessed. Diploid and triploid oysters were exposed to cultured A. minutum and compared to control diploid and triploid oysters fed T. Isochrysis. Experiments were repeated twice, in April and mid-May 2007, to investigate effects of maturation stage on oyster responses to A. minutum exposure. Oyster maturation stage, Paralytic Shellfish Toxin (PST) accumulation, as well as several digestive gland and hematological variables, were assessed at the ends of the exposures. In both experiments, triploid oysters accumulated more PSTs (approximately twice) than diploid oysters. Significant...
Tipo: Text
Palavras-chave: Oysters; Ploidy; Physiology; Harmful-algal bloom; Alexandrium minutum; PST accumulation.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11378/7988.pdf

Copepods Boost the Production but Reduce the Carbon Export Efficiency by Diatoms
Provedor de dados: 5
Autores: Moriceau, Brivaela; Iversen, Morten H.; Gallinar, Morgane; Evertsen, Antti-jussi O.; Le Goff, Manon; Beker, Beatriz; Boutorh, Julia; Corvaisier, Rudolph; Coffineau, Nathalie; Donval, Anne; Giering, Sarah L. C.; Koski, Marja; Lambert, Christophe; Lampit, Richard S.; Le Mercier, Alain; Masson, Annick; Stibor, Herwig; Stockenreiter, Maria; De La Rocha, Christina L.
The fraction of net primary production that is exported from the euphotic zone as sinking particulate organic carbon (POC) varies notably through time and from region to region. Phytoplankton containing biominerals, such as silicified diatoms have long been associated with high export fluxes. However, recent reviews point out that the magnitude of export is not controlled by diatoms alone, but determined by the whole plankton community structure. The combined effect of phytoplankton community composition and zooplankton abundance on export flux dynamics, were explored using a set of 12 large outdoor mesocosms. All mesocosms received a daily addition of minor amounts of nitrate and phosphate, while only 6 mesocosms received silicic acid (dSi). This resulted...
Tipo: Text
Palavras-chave: Biogenic silica; POC; Marine snow; Zooplankton; Mesocosm; Bay of Hopavagen; Plankton community; Biological pump.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00469/58029/60433.pdf

Caractérisation de bactéries pathogènes, Vibrio splendidus, isolées de bivalves marins
Provedor de dados: 5
Autores: Gay, Melanie; Waechter, Magali; Lambert, Christophe; Escoubas, Jean-michel; Cochennec, Nathalie; Nicolas, Jean-louis; Berthe, Franck; Le Roux, Frédérique.
Nowadays, cupped oyster, Crassostrea gigas, production is the main shellfish production in France. Spats cultivated on most farms are usually collected in the wild, but hatchery spats are becoming more numerous, and represent around 10% of today's cultivated spats. During the summer period, when the temperatures are higher, high mortality rates have been regularly observed in cupped in oyster C. gigas (60 to 100%) spats since 1991, both in hatcheries-nurseries and in their natural habitat. Over the last five years, these episodes have become a big concern for all the professionals.
Tipo: Text
Palavras-chave: Crassostrea gigas; Pathogène; Vibrio splendidus; Bactériologie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3277.pdf

Hemocyte characteristics in families of oysters, Crassostrea gigas, selected for differential survival during summer and reared in three sites
Provedor de dados: 5
Autores: Lambert, Christophe; Soudant, Phillippe; Degremont, Lionel; Delaporte, Maryse; Moal, Jeanne; Boudry, Pierre; Jean, Frédéric; Huvet, Arnaud; Samain, Jean-francois.
High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Riviere d'Auray (Brittany) and Ronce (Marennes-oleron Basin, Poitou Charentes).   Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered...
Tipo: Text
Palavras-chave: Genetic; Flow cytometry; Reactive oxygen species ROS; Adhesion; Hemocyte; Crassostrea gigas; Summer mortality.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3054.pdf

Exposure of marine mussels Mytilus spp. to polystyrene microplastics: Toxicity and influence on fluoranthene bioaccumulation
Provedor de dados: 5
Autores: Paul-pont, Ika; Lacroix, Camille; Gonzalez Fernandez, Carmen; Hegaret, Helene; Lambert, Christophe; Le Goic, Nelly; Frere, Laura; Cassone, Anne-laure; Sussarellu, Rossana; Fabioux, Caroline; Guyomarch, Julien; Albentosa, Marina; Huvet, Arnaud; Soudant, Philippe.
The effects of polystyrene microbeads (micro-PS; mix of 2 and 6 μm; final concentration: 32 μg L−1) alone or in combination with fluoranthene (30 μg L−1) on marine mussels Mytilus spp. were investigated after 7 days of exposure and 7 days of depuration under controlled laboratory conditions. Overall, fluoranthene was mostly associated to algae Chaetoceros muelleri (partition coefficient Log Kp = 4.8) used as a food source for mussels during the experiment. When micro-PS were added in the system, a fraction of FLU transferred from the algae to the microbeads as suggested by the higher partition coefficient of micro-PS (Log Kp = 6.6), which confirmed a high affinity of fluoranthene for polystyrene microparticles. However, this did not lead to a modification...
Tipo: Text
Palavras-chave: Microplastics; Fluoranthene; Mussel; Depuration; Oxidative system.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00344/45502/45848.pdf

Nanoplastics impaired oyster free living stages, gametes and embryos
Provedor de dados: 5
Autores: Tallec, Kevin; Huvet, Arnaud; Di Poi, Carole; Gonzalez-fernandez, Carmen; Lambert, Christophe; Petton, Bruno; Le Goic, Nelly; Berchel, Mathieu; Soudant, Philippe; Paul-pont, Ika.
In the marine environment, most bivalve species base their reproduction on external fertilization. Hence, gametes and young stages face many threats, including exposure to plastic wastes which represent more than 80% of the debris in the oceans. Recently, evidence has been produced on the presence of nanoplastics in oceans, thus motivating new studies of their impacts on marine life. Because no information is available about their environmental concentrations, we performed dose-response exposure experiments with polystyrene particles to assess the extent of micro/nanoplastic toxicity. Effects of polystyrene with different sizes and functionalization (plain 2-μm, 500-nm and 50-nm; COOH-50 nm and NH2-50 nm) were assessed on three key reproductive steps...
Tipo: Text
Palavras-chave: Oyster; Embryos; Gametes; Microplastics; Nanoplastics.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00453/56419/58090.pdf

Identification of Polyunsaturated Fatty Acids Synthesis Pathways in the Toxic Dinophyte Alexandrium minutum Using 13C-Labelling
Provedor de dados: 5
Autores: Remize, Marine; Planchon, Frederic; Loh, Ai Ning; Le Grand, Fabienne; Lambert, Christophe; Bideau, Antoine; Bidault, Adeline; Corvaisier, Rudolph; Volety, Aswani; Soudant, Philippe.
The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13CO2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum. The Dinophyte growth was monitored for 54 h using high-frequency sampling. A. minutum presented a growth in two phases. A lag phase was observed during the first 30 h of development and had been associated with the probable temporary encystment of Dinophyte cells. An exponential growth phase was then observed after t30. A. minutum rapidly incorporated 13C into 22:6n-3, which ended up being the most 13C-enriched...
Tipo: Text
Palavras-chave: PUFA synthesis; 22:6n-3; DHA; PKS pathway; Dinophyte; Alexandrium minutum; Encystment.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00654/76562/77688.pdf

Colonization of polystyrene microparticles by Vibrio crassostreae: light and electron microscopic investigation
Provedor de dados: 5
Autores: Foulon, Valentin; Le Roux, Frederique; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe; Paul-pont, Ika.
Microplastics collected at sea harbour a high diversity of microorganisms including some Vibrio genus members, raising questions about the role of microplastics as a novel ecological niche for potentially pathogenic microorganisms. In the present study we investigated the adhesion dynamics of Vibrio crassostreae on polystyrene microparticles (micro-PS) using electronic and fluorescence microscopy techniques. Micro-PS were incubated with bacteria in different media (Zobell culture medium and artificial seawater) with or without natural marine aggregates. The highest percentage of colonised particles (38-100%) was observed in Zobell culture medium, which may be related to nutrient availability for production of pili and exopolysaccharide adhesion structures....
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00351/46210/45908.pdf

Vibriosis in bivalves : review of recent molecular, biochemical, and physiological studies
Provedor de dados: 5
Autores: Paillard, Christine; Nicolas, Jean-louis; Le Chevalier, Patrick; Lambert, Christophe; Le Boulay, Christine; Berthe, Franck; Haras, Dominique.
The emergence of new vibriosis in the European Atlantic coasts has been associated with mass mortalities of molluscs causing important economic losses. For examples, Vibrio carchariae, a bacteria already isolated from shark, has been associated with a severe Haliotis epizooty in hatchery. In oysters, Crass()strea gigas, a strain closely related to Vibrio splendidus is suspected to be associated with summer mortalities.
Tipo: Text
Palavras-chave: Pathogenic vibrios; Bivales; Vibriosis; Bacteriology.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3287.pdf

Changes in biochemical and hemocyte parameters of the pacific oysters Crassostrea gigas fed T-Iso supplemented with lipid emulsions rich in eicosapentaenoic acid
Provedor de dados: 5
Autores: Delaporte, Maryse; Chu, Fu-lin; Langdon, Chris; Moal, Jeanne; Lambert, Christophe; Samain, Jean-francois; Soudant, Philippe.
The aim of this study was to assess the effect of dietary eicosapentaenoic acid (20:5n-3) on hemocyte parameters such as hemocyte concentration, phagocytosis, and non-stimulated reactive oxygen species (ROS) production in Pacific oysters Crassostrea gigas, as well on proximate biochemical and fatty acid compositions. One-year-old oysters (C. gigas) were fed T-Isochrysis aff. galbana(T-Iso), which is low in 20:5n-3, either alone or with supplements of a lipid emulsion rich in 20:5n-3 at 1%, 10% or 50% (dry weight of the algal ration) for up to 7 weeks. Changes in gill fatty acid composition demonstrated that the lipid emulsion was well ingested by oysters during the dietary conditioning. Biochemical analysis indicated that oysters fed supplements of 50%...
Tipo: Text
Palavras-chave: Polyunsaturated fatty acids; Immunology; Hemocytes; Eicosapentaenoic acid 20 : 5n 3; Crassostrea gigas; Bivalves.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2604.pdf

Exposure to the toxic dinoflagellate Alexandrium catenella modulates juvenile oyster Crassostrea gigas hemocyte variables subjected to different biotic conditions
Provedor de dados: 5
Autores: Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Miner, Philippe; Le Grand, Jacqueline; Lambert, Christophe; Le Goic, Nelly; Hegaret, Helene; Fabioux, Caroline.
The Pacific oyster Crassostrea gigas is an important commercial species cultured throughout the world. Oyster production practices often include transfers of animals into new environments that can be stressful, especially at young ages. This study was undertaken to determine if a toxic Alexandrium bloom, occurring repeatedly in French oyster beds, could modulate juvenile oyster cellular immune responses (i.e. hemocyte variables). We simulated planting on commercial beds by conducting a cohabitation exposure of juvenile, “specific pathogen-free” (SPF) oysters (naïve from the environment) with previously field-exposed oysters to induce interactions with new microorganisms. Indeed, toxic Alexandrium spp. exposures have been reported to modulate bivalve...
Tipo: Text
Palavras-chave: Crassostrea gigas; Alexandrium; Harmful algal blooms; Hemocyte; Microbial challenge.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00314/42523/41894.pdf

BABE : Comparaison des sites de Ronce et Baie de Veys, incidence sur la reproduction et les mortalités : Ecologie côtière, mortalités, croissance, environnement - Physiologie - Immunologie
Provedor de dados: 5
Autores: Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel; Seugnet, Jean-luc; Robert, Stephane; Ropert, Michel; Simonne, Charlotte; Hugonnet, Virginie; Moal, Jeanne; Pouvreau, Stephane; Huvet, Arnaud; Samain, Jean-francois; Lambert, Christophe; Soudant, Philippe; Frouel, Stephane; Choquet, Gwenaelle; Delaporte, Maryse; Paillard, Christine.
Four laboratories are involved in this multidisciplinary study: the Conchological Laboratory of Normandie (LCN), the Invertebrates Physiology Laboratory (LPI), the Université Bretagne Occidentale (LEMAR IHP) and the Conchological Laboratory of Poitou-Charentes (LCPC). The part of the study which is presented here (thematics "Coastal ecology") was produced in collaboration with the LCN. The data on the Bay of Veys was collected by Michel Ropert. This study aims at observing the "sites" effect on mortality and on the general biology of the animal, as well as measuring some environmental elements (e.g. water temperature, etc.). The geographical sites are Gefosse in the Bay of Veys (East Cotentin) and the Ronce bank in the south of the Marennes Oléron Bay. The...
Tipo: Text
Palavras-chave: Immunologie; Physiologie; Paramètres environnementaux; Croissance; Ecologie côtière; Baies des Veys Cotentin; Ronce   Charente Maritime; Comparaison sites; Reproduction; Mortalités; Crassostrea gigas; Huîtres.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/acte-3405.pdf

Cellular and biochemical responses of the oyster Crassostrea gigas to controlled exposures to metals and Alexandrium minutum
Provedor de dados: 5
Autores: Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Quere, Claudie; Bruneau, A; Riso, Ricardo; Auffret, Michel; Soudant, Philippe.
Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in...
Tipo: Text
Palavras-chave: Harmful algae; Metals; Oysters; Toxin accumulation; Physiological effects.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00169/28071/26286.pdf

Interactions between polystyrene microplastics and marine phytoplankton lead to species-specific hetero-aggregation
Provedor de dados: 5
Autores: Long, Marc; Paul-pont, Ika; Hegaret, Helene; Moriceau, Brivaela; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe.
To understand the fate and impacts of microplastics (MP) in the marine ecosystems, it is essential to investigate their interactions with phytoplankton as these may affect MP bioavailability to marine organisms as well as their fate in the water column. However, the behaviour of MP with marine phytoplanktonic cells remains little studied and thus unpredictable. The present study assessed the potential for phytoplankton cells to form hetero-aggregates with small micro-polystyrene (micro-PS) particles depending on microalgal species and physiological status. A prymnesiophycea, Tisochrysis lutea, a dinoflagellate, Heterocapsa triquetra, and a diatom, Chaetoceros neogracile, were exposed to micro-PS (2 μm diameter; 3.96 μg L−1) during their growth culture...
Tipo: Text
Palavras-chave: Polystyrene; Microplastic; Aggregates; Microalgae; Marine; Phytoplankton.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00389/50016/50735.pdf

Effect of local hydroclimate on phytoplankton groups in the Charente estuary
Provedor de dados: 5
Autores: Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian.
This study aimed to describe seasonal variations of phytoplankton abundances in relation to the physical and chemical (nutrients and metals) environment under the influence of freshwater input in the Charente river estuary (Marennes-Oléron bay, France) over three years, from 2011 to 2014. Phytoplankton abundances were determined using microscopy and flow cytometry. Considering high frequency temperature and salinity data, breakpoints in each series led to the identification of two local hydroclimatic periods: the first (2011 and early 2012) being warmer and higher in salinity than the second (from spring 2012 to the beginning of 2014). A multiblock PLS analysis highlighted the significant contribution of the physical environment (temperature, salinity and...
Tipo: Text
Palavras-chave: Hydroclimate; Estuary; Phytoplankton; Size composition; Nutrients; Trace metals.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00349/46005/45674.pdf

Etude des infections à vibrionaceae chez les larves de mollusques bivalves à partir d'un modèle larve de Pecten maximus
Provedor de dados: 5
Autores: Lambert, Christophe.
The control of diseases remains a question of major importance in order to reduce pathological risks in bivalve larval rearings. For such a purpose, the knowledge of diseases, pathogens and routes of infection is required. A new species of vibrio pathogenic to P. maximus larvae, Vibrio pectenicida, was described by phenotypic and genotypic characters. It belongs to the V. splendidus group, where sorne other new pathogenic species were already found. The pathogenesis of V. pectenicida was studied by histological methods and experimental exposures in conventional and axenic larval rearings. These studies assessed the pathogenic character of V. pectenicida strains and the lack of particular symptoms during the disease. The location ofbacteria in the tissues...
Tipo: Text
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00034/14562/11860.pdf

A rapid quantitative fluorescence-based bioassay to study allelochemical interactions from Alexandrium minutum
Provedor de dados: 5
Autores: Long, Marc; Tallec, Kevin; Soudant, Philippe; Lambert, Christophe; Le Grand, Fabienne; Sarthou, Geraldine; Jolley, Dianne; Hegaret, Helene.
Harmful microalgal blooms are a threat to aquatic organisms, ecosystems and human health. Toxic dinoflagellates of the genus Alexandrium are known to produce paralytic shellfish toxins and to release bioactive extracellular compounds (BECs) with potent cytotoxic, hemolytic, ichtyotoxic and allelopathic activity. Negative allelochemical interactions refer to the chemicals that are released by the genus Alexandrium and that induce adverse effects on the physiology of co-occurring protists and predators. Releasing BECs gives the donor a competitive advantage that may help to form dense toxic blooms of phytoplankton. However BECs released by Alexandrium minutum are uncharacterized and it is impossible to quantify them using classical chemical methods....
Tipo: Text
Palavras-chave: Harmful algal bloom; Alexandrium; Allelopathy; Cytotoxicity; PAM fluorometry; Bioassay.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00453/56424/58116.pdf

Interaction between toxic dinoflagellate Alexandrium catenella exposure and disease associated with herpesvirus OsHV-1μVar in Pacific oyster spat Crassostrea gigas
Provedor de dados: 5
Autores: Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Fabioux, Caroline; Lambert, Christophe; Miner, Philippe; Le Grand, Jacqueline; Petton, Bruno; Hegaret, Helene.
Blooms of toxic dinoflagellates can co-occur with mass mortality events associated with herpesvirus OsHV-1 μVar infection that have been decimating Pacific oyster Crassostrea gigas spat and juveniles every summer since 2008 in France. This study investigated the possible effect of a harmful dinoflagellate, Alexandrium catenella, a producer of Paralytic Shellfish Toxins (PSTs), upon the oyster spat–herpesvirus interaction. Oyster spat from a hatchery were challenged by cohabitation with oysters contaminated in the field with OsHV-1 μVar and possibly other pathogens. Simultaneously, the oysters were exposed to cultured A. catenella. Infection with OsHV-1 μVar and PST accumulation were measured after 4 days of experimental exposure.  Exposure to Alexandrium...
Tipo: Text
Palavras-chave: Crassostrea gigas; OsHV-1 mu Var; Harmful algal blooms; Alexandrium; Host-pathogen interaction; PST accumulation.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00269/38000/36101.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

Genetic and reproduction strategy in Crassostrea gigas mortality
Provedor de dados: 5
Autores: Moal, Jeanne; Bedier, Edouard; Fleury, Pierre-gildas; Langlade, Aime; Le Coguic, Yvette; Degremont, Lionel; Boudry, Pierre; Le Coz, Jean-rene; Pouvreau, Stephane; Enriquez-diaz, M.; Lambert, Christophe; Quere, Christele; Soudant, Philippe; Samain, Jean-francois.
Bi-parental families were produced in hatchery and tested in the field in 2001. Two sets of 5 families were constituted, selected on their high (R) and low (S) survival. These two sets were reared in Brittany from March to November 2002. Samplings were performed twice a month to obtain data on biometry, survival, reproductive cycle, biochemical composition, adenylate energy charge, hemolymph parameters (ions and defense system) and muscle strength. "R" and "S" oysters exhibited different reproductive effort and spawning strategy. "R" oysters allocated less energy in gonad than "S" ones and presented a complete spawning at the end of August contrary to the "S" which spawns partially. Mortality started in July when the seawater temperature reached 19 degree...
Tipo: Text
Palavras-chave: Summer; Reproduction; Oyster culture; Mortality; Genetic diversity; Commercial species; Breeding.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3345.pdf

Transcriptomic analysis of clam extra pallial fluids reveals immunity and cytoskeleton alterations in the first week of Brown Ring Disease development
Provedor de dados: 5
Autores: Rahmani, Alexandra; Corre, Erwan; Richard, Gaëlle; Bidault, Adeline; Lambert, Christophe; Oliveira, Louisi; Thompson, Cristiane; Thompson, Fabiano; Pichereau, Vianney; Paillard, Christine.
The Brown Ring Disease is an infection caused by the bacterium Vibrio tapetis on the Manila clam Ruditapes philippinarum. The process of infection, in the extrapallial fluids (EPFs) of clams, involves alteration of immune functions, in particular on hemocytes which are the cells responsible of phagocytosis. Disorganization of the actin-cytoskeleton in infected clams is a part of what leads to this alteration. This study is the first transcriptomic approach based on collection of extrapallial fluids on living animals experimentally infected by V. tapetis. We performed differential gene expression analysis of EPFs in two experimental treatments (healthy-against infected-clams by V. tapetis), and showed the deregulation of 135 genes. In infected clams, a...
Tipo: Text
Palavras-chave: Brown ring disease; V. tapetis; R. philippinarum; Hemocytes; Actin cytoskeleton; Beta-Thymosin; Coactosin; Resting cells.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00510/62131/66362.pdf

In vitro modulation of reactive oxygen and nitrogen intermediate (ROI/RNI) production in Crassostrea gigas hemocytes
Provedor de dados: 5
Autores: Lambert, Christophe; Soudant, Philippe; Jegaden, Marine; Delaporte, Maryse; Labreuche, Yannick; Moal, Jeanne; Samain, Jean-francois.
Bivalve hemocyte competence has been measured by quantifying functional characteristics, including reactive oxygen intermediate (ROI) production after activation with zymosan or phorbol myristate acetate (PMA). However, untreated oyster hemocytes also produce ROI and RNI (reactive nitrogen intermediates) after bleeding even if not stimulated by Zymosan or PMA. Extensive investigation of this parameter by flow cytometry showed that, in vitro, ROI/RNI production by untreated hemocytes maintained in seawater appeared to be independent of both bacterial burden in the serum and non-self particle phagocytosis. ROI/ RNI production in granulocytes was higher than in hyalinocytes and could be intensified when activated by zymosan but not by PMA. Both cell types...
Tipo: Text
Palavras-chave: NO synthase; NADPH oxidase; Flow cytometry; Reactive nitrogen intermediate RNI; Reactive oxygen intermediate ROI; Hemocytes; Crassostrea gigas.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3057.pdf

Effets de l'hydroclimat local sur les groupes de phytoplancton dans l'estuaire de la Charente
Provedor de dados: 5
Autores: Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian.
Cette étude s’inscrit dans le cadre du projet TOPHYPAC (2011-2014) financé par le programme “Pesticides” du Ministère de l’Écologie, du Développement durable et de l’Énergie. Ce travail vise à décrire les variations saisonnières des abondances de phytoplancton en lien avec l'environnement physique et chimique (nutriments et métaux) de l'estuaire de la Charente de 2011 à 2014. À partir des données d'abondances de groupes phytoplanctoniques déterminés par microscopie et par cytométrie de flux, les contributions relatives des variables environnementales sur la dynamique du phytoplancton ont été évaluées : dans ce but, une analyse PLS multibloc a été réalisée. Celle-ci souligne une contribution importante de l'environnement physique (température, salinité et...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00361/47173/47139.pdf

Microplastics in seafood: Benchmark protocol for their extraction and characterization
Provedor de dados: 5
Autores: Dehaut, Alexandre; Cassone, Anne-laure; Frere, Laura; Hermabessiere, Ludovic; Himber, Charlotte; Rinnert, Emmanuel; Riviere, Gilles; Lambert, Christophe; Soudant, Philippe; Huvet, Arnaud; Duflos, Guillaume; Paul-pont, Ika.
Pollution of the oceans by microplastics (&lt;5 mm) represents a major environmental problem. To date, a limited number of studies have investigated the level of contamination of marine organisms collected in situ. For extraction and characterization of microplastics in biological samples, the crucial step is the identification of solvent(s) or chemical(s) that efficiently dissolve organic matter without degrading plastic polymers for their identification in a time and cost effective way. Most published papers, as well as OSPAR recommendations for the development of a common monitoring protocol for plastic particles in fish and shellfish at the European level, use protocols containing nitric acid to digest the biological tissues, despite reports of...
Tipo: Text
Palavras-chave: Microplastics; Digestion; Method; Seafood products; Tissue; Plastic integrity.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00335/44582/44469.pdf

Physiological responses of Manila clams Venerupis (=Ruditapes) philippinarum with varying parasite Perkinsus olseni burden to toxic algal Alexandrium ostenfeldii exposure
Provedor de dados: 5
Autores: Lassudrie, Malwenn; Soudant, Philippe; Richard, Gaelle; Henry, N.; Medhioub, Walid; Da Silva, P.m.; Donval, Anne; Bunel, M.; Le Goïc, Nelly; Lambert, Christophe; De Montaudoin, X.; Fabioux, Caroline; Hegaret, Helene.
Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the...
Tipo: Text
Palavras-chave: Bivalve; Harmful algal bloom; Oxidative stress; Venerupis philippinarum; Alexandrium ostenfeldii; Perkinsus olseni.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00189/30022/28507.pdf

Anti-predator response of Haliotis tuberculata is modified after only one generation of domestication
Provedor de dados: 5
Autores: Roussel, Sabine; Bisch, T; Lachambre, S; Boudry, Pierre; Gervois, Jl; Lambert, Christophe; Huchette, S; Day, R.
Domestication of Haliotis tuberculata has only recently begun. During the process, we expect that behavioural and physiological traits may evolve to become more adapted to their captive environment. These modifications may result from intentional selection of production traits or unconscious and unintentional selection due to conditions experienced in the farm environment. To study this process at the earliest stage, the progeny of 3 different broodstocks obtained from wild parents, selected farmed abalone and randomly sampled farmed abalone, were studied. After rearing for 16 mo in separate tanks, offspring from the 3 progenies were placed together in sea cages at the same density. After 3 yr, behavioural traits were studied, and the immune status after a...
Tipo: Text
Palavras-chave: Predation; Hiding behaviour; Haliotis tuberculata; Domestication; Selection; Captive; Abalone.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00487/59841/62989.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

Interactions between microplastics and phytoplankton aggregates : Impact on their respective fates
Provedor de dados: 5
Autores: Long, Marc; Moriceau, Brivaela; Gallinari, Morgane; Lambert, Christophe; Huvet, Arnaud; Raffray, Jean; Soudant, Philippe.
Plastic debris are resistant to degradation, and therefore tend to accumulate in marine environment. Nevertheless recent estimations of plastic concentrations at the surface of the ocean were lower than expected leading the communities to seek new sinks. Among the different processes suggested we chose to focus on the transport of microplastics from the surface to deeper layers of the ocean via phytoplankton aggregates that constitute most of the sinking flux. Interactions between microplastics and aggregates were studied by building a new device: the flow-through roller tank that mimics the behaviour of laboratory made aggregates sinking through a dense layer of microplastics. Three types of aggregates formed from two different algae species (the diatom...
Tipo: Text
Palavras-chave: Microplastic sink; Vertical export; Diatom and cryptophyte aggregates; Settling rate; Permeability.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00259/37048/35557.pdf

Inter and intra-specific transcriptional and phenotypic responses of   Pseudo-nitzschia   under different nutrient conditions
Provedor de dados: 5
Autores: Lema, Anais Kimberley; Metegnier, Gabriel; Quéré, Julien; Latimier, Marie; Youenou, Agnes; Lambert, Christophe; Fauchot, Juliette; Le Gac, Mickael.
Untangling the functional basis of divergence between closely related species is a step towards understanding species dynamics within communities at both the evolutionary and ecological scales. We investigated cellular (i.e: growth, domoic acid production, nutrient consumption) and molecular (transcriptomic analyses) responses to varying nutrient concentrations across several strains belonging to three species of the toxic diatom genus Pseudo-nitzschia. Three main results were obtained. First, strains from the same species displayed similar transcriptomic, but not necessarily cellular, responses to the experimental conditions. It showed the importance of considering intra-specific diversity to investigate functional divergence between species. Second, a...
Tipo: Text
Palavras-chave: Phenotype; Transcriptomics; Pseudo-nitzschia; Divergence; Nutrients.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59392/62157.pdf

Implication of the Type IV Secretion System in the Pathogenicity of Vibrio tapetis, the Etiological Agent of Brown Ring Disease Affecting the Manila Clam Ruditapes philippinarum
Provedor de dados: 5
Autores: Rahmani, Alexandra; Delavat, François; Lambert, Christophe; Le Goic, Nelly; Dabas, Eric; Paillard, Christine; Pichereau, Vianney.
Vibrio tapetis is a Gram-negative bacterium that causes infections of mollusk bivalves and fish. The Brown Ring Disease (BRD) is an infection caused by V. tapetis that primarily affects the Manila clam Ruditapes philippinarum. Recent studies have shown that a type IV secretion system (T4SS) gene cluster is exclusively found in strains of V. tapetis pathogenic to clams. However, whether the T4SS is implicated or not during the infection process remains unknown. The aim of this study was to create and characterize a V. tapetis T4SS null mutant, obtained by a near-complete deletion of the virB4 gene, in order to determine the role of T4SS in the development of BRD. This study demonstrated that the T4SS is neither responsible for the loss of hemocyte adhesion...
Tipo: Text
Palavras-chave: Brown Ring Disease; Vibrio tapetis; Ruditapes philippinarum; Hemocytes; Type four secretion system; Rounding phenotype; Colonization; Mutagenesis.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00692/80383/83507.pdf

Cellular responses of Pacific oyster ( Crassostrea gigas ) gametes exposed in vitro to polystyrene nanoparticles
Provedor de dados: 5
Autores: Gonzalez-fernandez, Carmen; Tallec, Kevin; Le Goic, Nelly; Lambert, Christophe; Soudant, Philippe; Huvet, Arnaud; Suquet, Marc; Berchel, Mathieu; Paul-pont, Ika.
While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes. Spermatozoa and oocytes were exposed to four NPs concentrations ranging from 0.1 to 100 mg L−1 for 1, 3 and 5 h. NPs coated with carboxylic (PS-COOH) and amine groups (PS-NH2) were used to determine how surface properties influence the effects of nanoplastics. Results demonstrated the...
Tipo: Text
Palavras-chave: Nanoplastics; Oysters; Gametes; Cellular responses.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00443/55459/56976.pdf

Cellular and molecular hemocyte responses of the Pacific oyster, Crassostrea gigas, following bacterial infection with Vibrio aestuarianus strain 01/32
Provedor de dados: 5
Autores: Labreuche, Yannick; Lambert, Christophe; Soudant, Philippe; Boulo, Viviane; Huvet, Arnaud; Nicolas, Jean-louis.
The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Pathogenesis; Vibrio aestuarianus; Bivalve immunity.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2182.pdf

Vibrio aestuarianus zinc metalloprotease causes lethality in the Pacific oyster Crassostrea gigas and impairs the host cellular immune defenses
Provedor de dados: 5
Autores: Labreuche, Yannick; Le Roux, Frederique; Henry, Joel; Zatylny, Celine; Huvet, Arnaud; Lambert, Christophe; Soudant, Philippe; Mazel, Didier; Nicolas, Jean-louis.
Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemical and genetic approaches were developed. ECP protease activity and lethality were shown to be significantly reduced following incubation with metal chelators, suggesting the involvement of a zinc metalloprotease. An open reading frame of 1836 bp encoding a 611-aa metalloprotease (designated yam) was identified. The deduced protein sequence showed high homology to other Vibrio metalloproteases reported to be involved in pathogenicity. To further confirm the role of this enzyme in ECP...
Tipo: Text
Palavras-chave: Vibrio aestuarianus; Metalloprotease; Crassostrea gigas; Oyster; Hemocytes; Extracellular products.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00015/12649/9588.pdf

Contribution of resuspended sedimentary particles to dissolved iron and manganese in the ocean: An experimental study
Provedor de dados: 5
Autores: Cheize, Marie; Planquette, H.f.; Fitzsimmons, J.n.; Pelleter, Ewan; Sherrell, R.m.; Lambert, Christophe; Bucciarelli, E.; Sarthou, G.; Le Goff, Marion; Liorzou, Celine; Chéron, Sandrine; Viollier, E.; Gayet, Nicolas.
A number of trace metals play essential roles in marine ecosystem structure and biological productivity. Until recently, it has been argued that phytoplankton access primarily dissolved iron, while particulate iron was considered a refractory material with little use biologically and limited interaction with the dissolved pool. In order to assess the transfer mechanisms between sediment-sourced particulate trace metals and the dissolved pool, we conducted a 14-month incubation that reacted resuspended sediments with natural seawater, both originating from the Kerguelen area (KEOPS cruises; Southern Ocean), in the dark, and at concentrations replicating natural conditions. Three types of sediments were investigated (named BioSi, BioSi + Ca, and Basalt),...
Tipo: Text
Palavras-chave: Suspended particle dissolution; Sediment; Iron; Manganese; Biogenic silica; Southern Ocean; Kerguelen.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00460/57197/59166.pdf

Selection of  Vibrio crassostreae  relies on a plasmid expressing a type 6 secretion system cytotoxic for host immune cells
Provedor de dados: 5
Autores: Piel, Damien; Bruto, Maxime; James, Adele; Labreuche, Yannick; Lambert, Christophe; Janicot, Adrian; Chenivesse, Sabine; Petton, Bruno; Wegner, K. Mathias; Stoudmann, Candice; Blokesch, Melanie; Le Roux, Frederique.
Pacific oyster mortality syndrome affects juveniles of Crassostrea gigas oysters and threatens the sustainability of commercial and natural stocks of this species. Vibrio crassostreae has been repeatedly isolated from diseased animals and the majority of the strains have been demonstrated to be virulent for oysters. In this study we showed that oyster farms exhibited a high prevalence of a virulence plasmid carried by V. crassostreae while oysters, at an adult stage, were reservoirs of this virulent population. The pathogenicity of V. crassostreae depends on a novel transcriptional regulator, which activates the bidirectional promoter of a Type 6 Secretion System (T6SS) genes cluster. Both the T6SS and a second chromosomal virulence factor, r5.7, are...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00510/62129/66343.pdf

Impact of the toxic dinoflagellate Alexandrium catenella on Pacific oyster reproductive output: application of flow cytometry assays on spermatozoa
Provedor de dados: 5
Autores: Le Goic, Nelly; Hegaret, Helene; Fabioux, Caroline; Miner, Philippe; Suquet, Marc; Lambert, Christophe; Soudant, Philippe.
The toxic dinoflagellate Alexandrium catenella recurrently blooms on the coasts of France and produces Paralytic Shellfish Toxins (PSTs) that accumulate in bivalves. These toxins can affect various physiological functions including reproduction. The present study aims to validate measurements of sperm viability, DNA content and mitochondrial membrane potential in Pacific oyster Crassostrea gigas using flow cytometry coupled with fluorescent markers, and to use these measurements to assess the cellular parameters of sperm from Pacific oysters exposed to A. catenella. These parameters may influence fertilization, embryogenesis and larval development in free-spawning shellfish. Sperm viability and DNA content estimation were assessed using SYBR-14, which only...
Tipo: Text
Palavras-chave: Harmful algal bloom; Sperm quality; Cellular parameters; Flow cytometry; Pacific oyster; Crassostrea gigas; Alexandrium catenella.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26853/24982.pdf

Constraints and Priorities for Conducting Experimental Exposures of Marine Organisms to Microplastics
Provedor de dados: 5
Autores: Paul-pont, Ika; Tallec, Kevin; Gonzalez-fernandez, Carmen; Lambert, Christophe; Vincent, Dorothee; Mazurais, David; Zambonino-infante, Jose-luis; Brotons, Guillaume; Lagarde, Fabienne; Fabioux, Caroline; Soudant, Philippe; Huvet, Arnaud.
Marine plastic pollution is a major environmental issue. Given their ubiquitous nature and small dimensions, ingestion of microplastic (MP) and nanoplastic (NP) particles and their subsequent impact on marine life are a growing concern worldwide. Transfers along the trophic chain, including possible translocation, for which the hazards are less understood, are also a major preoccupation. Effects of MP ingestion have been studied on animals through laboratory exposure, showing impacts on feeding activity, reserve depletion and inflammatory responses, with consequences for fitness, notably reproduction. However, most experimental studies have used doses of manufactured virgin microspheres that may not be environmentally realistic. As for most...
Tipo: Text
Palavras-chave: Microplastics; Nanoplastics; Experimental exposure; Impacts; Marine organisms; Physiology.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00449/56088/57621.pdf

Influence of gametogenesis pattern and sex on paralytic shellfish toxin levels in triploid Pacific oyster Crassostrea gigas exposed to a natural bloom of Alexandrium minutum
Provedor de dados: 5
Autores: Hermabessiere, Ludovic; Fabioux, C.; Lassudrie, Malwenn; Boullot, F.; Long, Marc; Lambert, Christophe; Le Goic, N.; Gouriou, Jeremie; Le Gac, Mickael; Chapelle, Annie; Soudant, P.; Hegaret, Helene.
This study investigated the effect of gametogenesis pattern and sex on levels of paralytic shellfish toxins (PST) accumulated by triploid oysters Crassostrea gigas exposed to a natural bloom of the toxic dinoflagellate Alexandrium minutum in the Bay of Brest (Western Brittany, France), over the summer 2014. Toxin accumulation in oysters was proposed to be influenced by the proportion of energy allocated to reproduction versus other metabolisms, as proposed by Haberkorn et al. (2010). Thus, we hypothesized that triploid oysters with different gametogenesis patterns (α or β, producing respectively numerous gametes or rare gametes) could result in differences in toxin accumulation. Toxin level could also be different according to the gender of the oysters. To...
Tipo: Text
Palavras-chave: Crassostrea gigas; Alexandrium minutum; Harmful algal bloom (HAB); Paralytic shellfish toxin (PST); Gametogenesis pattern; Triploid.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00307/41801/41010.pdf

Effects of Alexandrium minutum exposure on nutrition-related processes and reproductive output in oysters Crassostrea gigas
Provedor de dados: 5
Autores: Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Moal, Jeanne; Suquet, Marc; Gueguen, Marielle; Sunila, Inke; Soudant, Philippe.
This study assessed the effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon nutrition related processes and reproductive output of the Pacific oyster, Crassostrea gigas. Oysters were exposed to A. minutum, Paralytic Shellfish Toxins (PST) producer and compared to a control batch of oysters fed Isochrysis galbana clone Tahitian (T.Iso). The experiment was performed in June 2008, when oysters were found ripe. Several physiological variables of oysters, such as PSTs accumulation, digestive gland and histological observations as well as spermatozoa quality, were measured at the end of the exposure. Results indicate that the digestive gland was greatly impacted upon A. minutum exposure. Monoacylglycerol and...
Tipo: Text
Palavras-chave: Harmful algae; Alexandrium minutum; Oyster; Nutrition-related processes; Reproductive output.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11927/8653.pdf

Flow cytometric assessment of morphology, viability, and production of reactive oxygen species of Crassostrea gigas oocytes. Application to Toxic dinoflagellate (Alexandrium minutum) exposure
Provedor de dados: 5
Autores: Le Goic, Nelly; Hegaret, Helene; Boulais, Myrina; Beguel, Jean-philippe; Lambert, Christophe; Fabioux, Caroline; Soudant, Philippe.
The Pacific oyster Crassostrea gigas accounts for a large part of shellfish aquaculture production worldwide. Aspects of morphological and functional characteristics of oyster oocytes remain poorly documented, and traditional techniques, such as microscopic observations of shape or fertilization rate, are time and space consuming. The purpose of this study was to assess for the first time viability and reactive oxygen species (ROS) production of Pacific oyster oocytes using flow cytometry (FCM) and to apply this method to determine oocyte responses to in vitro exposure to the toxic dinoflagellate Alexandrium minutum. A culture of A. minutum caused a significant increase in oocyte ROS production, which gradually increased with the age of the culture, but...
Tipo: Text
Palavras-chave: Pacific oyster; Gamete quality; ROS production; Viability; Flow cytometry; Ecotoxicology.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00216/32760/31321.pdf

Study of the antioxidant capacity in gills of the Pacific oyster Crassostrea gigas in link with its reproductive investment
Provedor de dados: 5
Autores: Beguel, Jean-philippe; Huvet, Arnaud; Quillien, Virgile; Lambert, Christophe; Fabioux, Caroline.
Energy allocation principle is a core element of life-history theory in which "the cost of reproduction" corresponds to an acceleration of senescence caused by an increase in reproductive investment. In the "theory of aging", senescence is mainly due to the degradation of lipids, proteins and DNA by reactive oxygen species (ROS), by-products of oxidative metabolism. Some studies have shown that oxidative stress susceptibility could be a cost of reproduction. The present study investigates the effect of reproductive investment on antioxidant capacity in the gills of a species with a very high reproductive investment, the Pacific oyster Crassostrea gigas. We used RNA interference targeting the oyster vasa-like gene (Oyvlg) to produce oysters with contrasted...
Tipo: Text
Palavras-chave: Antioxidant capacity; Crassostrea gigas; Reproduction; RNA interference; ROS.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00116/22744/21494.pdf

Reply to Lenz et al.: Quantifying the smallest microplastics is the challenge for a comprehensive view of their environmental impacts
Provedor de dados: 5
Autores: Huvet, Arnaud; Paul-pont, Ika; Fabioux, Caroline; Lambert, Christophe; Suquet, Marc; Thomas, Yoann; Robbens, Johan; Soudant, Philippe; Sussarellu, Rossana.
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00345/45604/45224.pdf

Nutrition and reproduction are key parameters in the interaction process leading to Crassostrea gigas oyster summer mortality in France
Provedor de dados: 5
Autores: Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Mazurie, Joseph; Mazurie, Joseph; Martin, Jean-louis; Moal, Jeanne; Mathieu, Michel; Pouvreau, Stephane; Lambert, Christophe; Escoubas, Jean-michel; Nicolas, Jean-louis; Le Roux, Frédérique; Renault, Tristan; Burgeot, Thierry; Bacher, Cedric; Boudry, Pierre.
Complex interactions between oyster, environment and pathogens were observed during the MOREST (2001-2005) project on summer mortality events of Crassostrea gigas oysters in France. The talk will show how nutrition level increasing reproductive intensity generates a risk for pathogen infection under synergistic effect of temperature and stress. Moreover, a genetic component is associated to specific reproductive performances and spawning behaviour. To better understand origin of such resistance or susceptibility to summer mortality, other characteristics as stress susceptibility, energy management and hemocyte activities of oysters from the two phenotypes were compared. This first comparison suggests interactions between stress, reproduction and defence...
Tipo: Text
Palavras-chave: Genetic; Pathologie; Mortality; Crassostrea gigas; Pacific oyster; Reproduction; Nutrition; Physilogy.
Ano: 2006
URL: https://archimer.ifremer.fr/doc/2006/acte-3467.pdf

Oyster reproduction is affected by exposure to polystyrene microplastics
Provedor de dados: 5
Autores: Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goic, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-pont, Ika; Soudant, Philippe; Huvet, Arnaud.
Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS...
Tipo: Text
Palavras-chave: Microplastic; Reproduction; Energy allocation; Oyster.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00311/42233/41600.pdf

Microplastic bacterial communities in the Bay of Brest: Influence of polymer type and size
Provedor de dados: 5
Autores: Frere, Laura; Maignien, Lois; Chalopin, Morgane; Huvet, Arnaud; Rinnert, Emmanuel; Morrison, Hilary; Kerninon, Sandrine; Cassone, Anne-laure; Lambert, Christophe; Reveillaud, Julie; Paul-pont, Ika.
Microplastics (&lt;5 mm) exhibit intrinsic features such as density, hydrophobic surface, or high surface/volume ratio, that are known to promote microbial colonization and biofilm formation in marine ecosystems. Yet, a relatively low number of studies have investigated the nature of microplastic associated bacterial communities in coastal ecosystems and the potential factors influencing their composition and structure. Here, we characterized microplastics collected in the Bay of Brest by manual sorting followed by Raman spectroscopy and studied their associated bacterial assemblages using 16S amplicon high-throughput sequencing. Our methodology allowed discriminating polymer type (polyethylene, polypropylene and polystyrene) within small size ranges...
Tipo: Text
Palavras-chave: Bacteria; Microplastics; Coastal ecosystem; Metabarcoding; Vibrios.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00449/56082/57614.pdf

Metabolic responses of clam Ruditapes philippinarum exposed to its pathogen Vibrio tapetis in relation to diet
Provedor de dados: 5
Autores: Richard, Gaelle; Guerard, Fabienne; Corporeau, Charlotte; Lambert, Christophe; Paillard, Christine; Pernet, Fabrice.
We investigated the effect of brown ring disease (BRD)1 development and algal diet on energy reserves and activity of enzymes related to energy metabolism, antioxidant system and immunity in Manila clam, Ruditapes philippinarum. We found that algal diet did not impact the metabolic response of clams exposed to Vibrio tapetis. At two days post-injection (dpi), activities of superoxide dismutase and glutathione peroxidase (GPx) decreased whereas activities of nitric oxide synthase (iNOS) and catalase increased in infected clams, although no clinical signs were visible (BRD-). At 7 dpi, activities of several antioxidant and immune-related enzymes were markedly increased in BRD-likely indicating an efficient reactive oxygen species (ROS) scavenging compared to...
Tipo: Text
Palavras-chave: Antioxidant enzymes; Immunity; Energetic metabolism; Ruditapes philippinarum; Vibrio tapetis.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00316/42684/42057.pdf

Allelochemicals from Alexandrium minutum induce rapid inhibition of metabolism and modify the membranes from Chaetoceros muelleri
Provedor de dados: 5
Autores: Long, Marc; Tallec, Kevin; Soudant, Philippe; Le Grand, Fabienne; Donval, Anne; Lambert, Christophe; Sarthou, Geraldine; Jolley, Dianne F.; Hegaret, Helene.
Allelochemical interactions are likely to be a contributing factor explaining the success of large blooms of the harmful marine dinoflagellate Alexandrium, however, the physiological mechanisms of allelochemical interactions remain poorly described. Here we investigated the sub-lethal effects (on an hourly scale) of a filtrate containing allelochemicals from Alexandrium minutum on the physiology of the common diatom Chaetoceros muelleri. The filtrate induced deleterious effects to the diatom physiology within only 30 min of exposure. Esterase activity and photosynthesis were drastically inhibited, with up to 34% of the population being metabolically inactive and up to 30% reduction in photosystem II quantum yield when exposed to the filtrate. In addition,...
Tipo: Text
Palavras-chave: Allelopathy; Alexandrium; Metabolism; Photoinhibition; Lipids; Pigments.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00460/57133/59748.pdf

Effect of a mono-specific algal diet on immune functions in two bivalve species - Crassostrea gigas and Ruditapes philippinarum
Provedor de dados: 5
Autores: Delaporte, Maryse; Soudant, Philippe; Moal, Jeanne; Lambert, Christophe; Quere, Claudie; Miner, Philippe; Choquet, Gwenaelle; Paillard, Christine; Samain, Jean-francois.
The impact of diets upon the fatty acid composition of haemocyte polar lipids and consequently upon immune parameters has been tested in the oyster Crassostrea gigas and the clam Ruditapes philippinarum. Oysters and clams were fed each of three cultured algae: Chaetoceros calcitrans, which is rich in 20:5(n-3) and 20:4(n-6) and poor in 22:6(n-3) fatty acids; T-Iso (Isochrysis sp.), which is rich in 22:6(n-3) and deficient in 20:5(n-3) and 20:4(n-6); and Tetraselmis suecica, which is deficient in 22:6(n-3) and contains only small amounts of 20:5(n-3) and 20:4(n-6). Fatty acid composition of haemocyte polar lipids was greatly affected by the diet. Oysters and clams fed C. calcitrans maintained a higher proportion of 20:5(n-3) and 20:4(n-6) in their haemocyte...
Tipo: Text
Palavras-chave: Ruditapes philippinarum; Crassostrea gigas; Polyunsaturated fatty acids; Phagocytosis; Oxidative activity; Haemocyte membrane; Nutrition; Immunology; Bivalve; Immunologie; Bivalve; Ruditapes philippinarum; Crassostrea gigas; Acides gras poly insatures; Phagocytose; Flambee respiratoire; Membrane; Hemocyte; Nutrition.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-354.pdf

Domestication modifies behaviour of first generation of domesticated abalone
Provedor de dados: 5
Autores: Roussel, Sabine; Bish, Thomas; Day, Rob; Boudry, Pierre; Huchette, Sylvain; Lambert, Christophe; Lachambre, Sébastien.
The domestication of Haliotis tuberculata began recently. During this domestication process, abalone may acquire behavioural and physiological traits to become more adapted to their captive environment. These modifications could be the result of intentional selection on production traits, or of unintentional selection due to specific conditions experienced in the farm environment. In order to study this process, progenies of 3 different broodstock origins were studied. Wild abalone, farmed abalone selected for faster growth at 5% selection pressure and randomly selected farmed abalone were used as broodstock. Farmed abalone were the third generation of abalone resulting from systematic mating between wild and farmed broodstock (either males or females were...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00404/51546/52138.pdf

Do transparent exopolymeric particles (TEP) affect the toxicity of nanoplastics on Chaetoceros neogracile?
Provedor de dados: 5
Autores: González-fernández, Carmen; Toullec, Jordan; Lambert, Christophe; Le Goïc, Nelly; Seoane, Marta; Moriceau, Brivaela; Huvet, Arnaud; Berchel, Mathieu; Vincent, Dorothée; Courcot, Lucie; Soudant, Philippe; Paul-pont, Ika.
The potential presence of nanoplastics (NP) in aquatic environments represents a growing concern regarding their possible effects on aquatic organisms. The objective of this study was to assess the impact of polystyrene (PS) amino-modified particles (50  nm PSNH2) on the cellular and metabolic responses of the diatom Chaetoceros neogracile cultures at two essential phases of the growth cycle, i.e. exponential (division) and stationary (storage) phases. Both cultures were exposed for 4 days to low (0.05 μg mL−1) and high (5 μg mL−1) concentrations of PS-NH2. Exposure to NP impaired more drastically the major cellular and physiological parameters during exponential phase than during the stationary phase. Only an increase in ROS production was observed at...
Tipo: Text
Palavras-chave: Nanoplastics; Diatoms; Physiology; Transparent exopolymer particles.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00491/60235/63627.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