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| Registros recuperados: 68 | |
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| 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 |
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| Da Costa, Fiz; Le Grand, Fabienne; Quere, Claudie; Bougaran, Gael; Cadoret, Jean-paul; Robert, Rene; Soudant, Philippe. |
| Standard and mutant Tisochrysis lutea strains were grown in batch culture for 10 days under nitrogen (N)-replete and N-reduced conditions to determine the effects of N supply in culture medium and growth phase on microalgal physiology and biochemistry. These two T. lutea strains were compared in terms of growth, morphology, associated free-living bacterial community, viability, intracellular lipid content (as measured by Bodipy staining), chlorophyll autofluorescence, and biochemical composition, with a focus on lipid class and fatty acid compositions. The standard strain (T) reached higher cell counts regardless of N supply in culture medium. In both T. lutea strains, microalgal final cell density was significantly lower in N-reduced medium. Carbohydrates... |
| Tipo: Text |
Palavras-chave: Tisochrysis lutea; Nitrogen limitation; Growth phase; Flow cytometry; Fatty acids; Lipid classes. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00399/51074/51936.pdf |
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| Da Costa Gonzalez, Fiz; Robert, Rene; Quere, Claudie; Wikfors, Gary H.; Soudant, Philippe. |
| Essential fatty acids (EFA) are important for bivalve larval survival and growth. The purpose of this study was to quantitatively assess for the first time through a mass-balance approach dietary EFA incorporation and synthesis within Crassostrea gigas larvae. A first experiment was carried out using two microalgae, Tisochrysis lutea (T) and Chaetoceros neogracile (Cg), as mono- and bi-specific diets. A second experiment using a similar design was performed to confirm and extend the results obtained in the first. Flow-through larval rearing was used for accurate control of food supply and measurement of ingestion. Non-methylene-interrupted fatty acids were synthetized from precursors supplied in the diet: 16:1n-7 and 18:1n-9, mediated by Delta 5... |
| Tipo: Text |
Palavras-chave: Fatty acid; Larvae; Lipids; Metabolism; Oyster; Synthesis. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00268/37962/36086.pdf |
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| Vignier, Julien; Rolton, Anne; Soudant, Philippe; Chu, Fu-lin E.; Robert, Rene; Volety, Aswani K.. |
| The 2010 explosion of the Deepwater Horizon (DWH) oil rig generated the largest marine oil spill in US history with millions of barrels of crude oil released in the Gulf of Mexico (GoM). The eastern oyster, Crassostrea virginica, is an ecologically and economically important species in the northern GoM. Due to its biological characteristics (sessile, filter feeding), juvenile oysters may have been affected. This study investigated the effects of surface-collected DWH oil prepared as high-energy water-accommodated fraction (HEWAF) on the survival of 2-month-old oyster spat, and evaluated the potential impacts of HEWAF on particle clearance rate and spat tissue. Exposure of oysters to a range of oil/HEWAF (0-7-66-147-908-3450 mu g tPAH50 (sum of 50... |
| Tipo: Text |
Palavras-chave: Oyster spat; Deepwater Horizon oil; Sublethal; Tissue; Inflammatory response; Histopathology. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53615/54548.pdf |
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| 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 |
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| 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 |
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| Fabioux, Caroline; Sulistiyani, Yeni; Haberkorn, Hansy; Hegaret, Helene; Amzil, Zouher; Soudant, Philippe. |
| Harmful algal blooms of Alexandrium spp. dinoflagellates regularly occur in French coastal waters contaminating shellfish. Studies have demonstrated that toxic Alexandrium spp. disrupt behavioural and physiological processes in marine filter-feeders, but molecular modifications triggered by phycotoxins are less well understood. This study analyzed the mRNA levels of 7 genes encoding antioxidant/detoxifying enzymes in gills of Pacific oysters (Crassostrea gigas) exposed to a cultured, toxic strain of A. minutum, a producer of paralytic shellfish toxins (PST) or fed Tisochrysis lutea (T. lutea, formerly Isochrysis sp., clone Tahitian (T. iso)), a non-toxic control diet, in four repeated experiments. Transcript levels of sigma-class glutathione S-transferase... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium minutum; Paralytic shellfish toxins; Antioxidant enzymes; Detoxification enzymes; MRNA. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38601/38623.pdf |
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| 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 |
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| Dudognon, Tony; Soudant, Philippe; Seguineau, Catherine; Quere, Claudie; Auffret, Michel; Kraffe, Edouard. |
| Sessile animals that live on the foreshore undergo tidal cycles, and have to face variations in physical and chemical parameters such as oxygen concentration. During emersion, availability of dissolved oxygen can be lowered for bivalves, which have only a small reserve of seawater inside their closed shell. Differences in oxygen concentration are thus expected to lead to modifications of the metabolism, including changes in mitochondrial activity. Previous studies investigated air exposure under extreme conditions, which do not always reflect environmental conditions these invertebrates have to cope with. In this study, oxidative capacities of gill mitochondria of the oyster Crassostrea gigas were studied during a tidal cycle period, by comparing oysters... |
| Tipo: Text |
Palavras-chave: Mitochondria; Oxygen consumption; ATP production; Respiratory chain inhibitor; Crassostrea gigas. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00157/26854/24981.pdf |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Gueguen, Marielle; Baron, Regis; Bardouil, Michele; Haberkorn, Hansy; Soudant, Philippe; Truquet, Philippe; Lassus, Patrick. |
| The purpose of this study was to assess paralytic phycotoxin uptake in diploid and triploid oysters at two stages of their sexual cycle corresponding to their status in early summer (June) and winter (November). Samples of diploid and triploid oysters were exposed to a toxic culture of Alexandrium minutum for 4 days in each season. No significant differences in filtration or clearance rates were observed during either November or June experiments. When diploid oysters were at resting stage (November), toxin uptake showed no significant difference between the ploidy classes. In contrast, when the diploid oysters were at the peak of their sexual maturation (June), the triploid oysters were seen to accumulate almost double the amount of paralytic toxins as... |
| Tipo: Text |
Palavras-chave: Paralytic shellfish poisoning; Crassostrea gigas; Diploid; Triploid; Contamination. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19796/17487.pdf |
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| 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 |
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| Vignier, J.; Rolton, A.; Soudant, Philippe; Chu, F. L. E.; Robert, Rene; Volety, A. K.. |
| The Deepwater Horizon (DWH) disaster released crude oil in the Gulf of Mexico for 87 days, overlapping with the reproductive season and recruitment of the oyster Crassostrea virginica. The pelagic larval life stages of C. virginica are particularly vulnerable to contaminants such as polycyclic aromatic hydrocarbons (PAHs) and oil droplets. Based on their lipophilic properties, PAHs and oil droplets can adsorb onto phytoplankton and filter-feeding C. virginica larvae may be exposed to these contaminants bound to suspended sediment, adsorbed onto algal and other particles, or in solution. This study examined the effects of exposure of C. virginica larvae to algae mixed with DWH oil. In a 14-day laboratory exposure, 5 day-old C. virginica larvae were exposed... |
| Tipo: Text |
Palavras-chave: Deepwater Horizon oil; Droplet; Oyster larvae; Dietary exposure; PAH. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00473/58423/61445.pdf |
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| 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 |
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| Registros recuperados: 68 | |
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