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| Registros recuperados: 20 | |
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| Gonzalez, Marcelo; Gueguen, Yannick; Destoumieux Garzon, Delphine; Romestand, Bernard; Fievet, Julie; Pugniere, M; Roquet, F; Escoubas, Jean-michel; Vandenbulcke, F; Levy, O; Saune, Laure; Bulet, P; Bachere, Evelyne. |
| A cDNA sequence with homologies to members of the LPS-binding protein and bactericidal/permeability-increasing protein (BPI) family was identified in the oyster Crassostrea gigas. The recombinant protein was found to bind LIPS, to display bactericidal activity against Escherichia coli, and to increase the permeability of the bacterial cytoplasmic membrane. This indicated that it is a BPI rather than an LPS-binding protein. By in situ hybridization, the expression of the C gigas BPI (Cg-bpi) was found to be induced in hemocytes after oyster bacterial challenge and to be constitutive in various epithelia of unchallenged oysters. Thus, Cg-bpi transcripts were detected in the epithelial cells of tissues/organs in contact with the external environment (mantle,... |
| Tipo: Text |
Palavras-chave: Oyster innate immunity; Mollusk; Hemocyte; Epithelia; Antimicrobial. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3564.pdf |
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| 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 |
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| Gagnaire, Beatrice; Gay, Melanie; Huvet, Arnaud; Daniel, Jean-yves; Saulnier, Denis; Renault, Tristan. |
| To assess the impact of pollution induced by pesticides on Pacific oyster, Crassostrea gigas, health in France, in vivo effects of combined pesticide exposure and bacterial challenge on cell activities and gene expression in hemocytes were tested using flow cytometry and real-time PCR. As a first step, an in vivo model of experimental contamination was developed. Pacific oysters were exposed to a mixture of eight pesticides (atrazine, glyphosate, alachlor, metolachlor, fosetyl-alumimium, terbuthylazine, diuron and carbaryl) at environmentally relevant concentrations over a 7-day period. Hemocyte parameters (cell mortality, enzyme activities and phagocytosis) were monitored using flow cytometry and gene expression was evaluated by real-time PCR (RT-PCR).... |
| Tipo: Text |
Palavras-chave: Gene expression; Flow cytometry; Vibrio splendidus; Pathogenesis; Phagocytosis; Hemocyte; Pesticides; Bivalve immunity; Crassostrea gigas; Pacific oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3022.pdf |
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| Lambert, Christian; Nicolas, Jean-louis; Bultel, Valérie. |
| Using a chemiluminescence (CL) test, it had been previously demonstrated that Vibrio pectenicida, which is pathogenic to Pecten maximus larvae, was able to inhibit completely the CL activity of P, maximus hemocytes and partially inhibit those of Crassostrea gigas, Conversely, a Vibrio sp, strain, S322, pathogenic to C,gigas larvae was more active in reducing the CL activity of oyster hemocytes than of scallop hemocytes, Using this same CL biotest, V, pectenicida and S322 cytoplasmic extracts were shown to reproduce CL inhibition while the cytoplasmic extract of a nonpathogenic strain (U1, Pseudoalteromonas) was without effect. Moreover, cytoplasmic extract as well as live V, pectenicida cells provoked, within a few hours, death of P. maximus hemocytes... |
| Tipo: Text |
Palavras-chave: Bivalves; Hemocyte; Toxin; Chemiluminescence; Crassostrea gigas; Pecten maximus; Vibrio pectenicida. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-466.pdf |
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| Moreau, Pierrick. |
| The thesis work is part of the very current issue on mass mortality outbreaks affecting Pacific oyster, C. gigas, spat and juveniles and questions about the involvement of pesticides in this phenomenon. The first part of this thesis was devoted to study the effects of pesticides on hemocyte parameters in the Pacific oyster (in vitro and in vivo). The immunomodulator effect of selected pesticides (alone or in mixture) has been explored principally through flow cytometry. The second part concerned the study of the effects of a pesticides mixture on OsHV-1 itself. No direct effects have been reported on the viral particles in presence of the pollutants. Moreover, pesticide effects on Pacific oysters were also explored through experimental pathology assays... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Pesticides; OsHV-1; Autophagy; Immunity; Hemocyte; Pathology. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00226/33740/32149.pdf |
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| Ben Cheikh, Yosra; Travers, Marie-agnes; Le Foll, Frank. |
| The pathogenic strain V. splendidus 10/068 1T1 has previously been reported for its virulence to the blue mussel and for its capacity to alter immune responses. In this study, we expanded the knowledge on hemocyte-pathogen interactions by using in vitro and in vivo assays. V. splendidus 10/068 1T1 severely inhibited cell adhesion and acidic vacuole formation unlike the innocuous phylogenetically related V. splendidus 12/056 M24T1 which had no effect on these cell functions. Furthermore, the virulent bacteria decreased hemocyte viability (59% of viability after 24 h). Infection dynamics were explored by using a model based on water tank cohabitation with septic mussels infected by GFP-tagged V. splendidus 10/068 1T1. Experimental infections were... |
| Tipo: Text |
Palavras-chave: Innate immunity; Bivalves; Vibrio; Infection; Experimental model; Hemocyte. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00400/51136/53772.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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| Bachere, Evelyne; Rosa, Rafael Diego; Schmitt, Paulina; Poirier, Aurore; Merou, Nicolas; Charriere, Guillaume; Destoumieux-garzon, Delphine. |
| Oysters are sessile filter feeders that live in close association with abundant and diverse communities of microorganisms that form the oyster microbiota. In such an association, cellular and molecular mechanisms have evolved to maintain oyster homeostasis upon stressful conditions including infection and changing environments. We give here cellular and molecular insights into the Crassostrea gigas antimicrobial defense system with focus on antimicrobial peptides and proteins (AMPs). This review highlights the central role of the hemocytes in the modulation and control of oyster antimicrobial response. As vehicles for AMPs and other antimicrobial effectors, including reactive oxygen species (ROS), and together with epithelia, hemocytes provide the oyster... |
| Tipo: Text |
Palavras-chave: Mollusk; Immunity; Antimicrobial peptide; Hemocyte; Defensin. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36552/35097.pdf |
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| Denoix, Michael. |
| Depuis la fin des années soixante, la conchyliculture française doit faire face à des mortalités importantes d'huître plate, Ostrea edulis, causées entre autres, par le protozoaire, Bonamia ostreae, responsable de la bonamiose. Peu de moyens sont à l'heure actuelle à la disposition des professionnels pour lutter contre cette maladie. L'obtention d'animaux résistants à cette infection est une voie retenue et explorée par l'Ifremer pour combattre la bonamiose et tenter d'apporter des solutions aux conchyliculteurs. Dans cette optique, l'Ifremer, a entrepris un programme de sélection pour obtenir des animaux résistants en exerçant une pression de sélection par inoculation de parasites purifiés dans la cavité péricardique d'animaux anesthésiés. Les premières... |
| Tipo: Text |
Palavras-chave: Huître plate; Ostrea edulis; Bonamia ostreae; Hemocyte; Parasite. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00033/14443/11742.pdf |
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| 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 |
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| Lassudrie Duchesne, Malwenn; Hegaret, Helene; Wikfors, Gary H; Mirella Da Silva, Patricia. |
| Bivalves were long thought to be “symptomless carriers” of marine microalgal toxins to human seafood consumers. In the past three decades, science has come to recognize that harmful algae and their toxins can be harmful to grazers, including bivalves. Indeed, studies have shown conclusively that some microalgal toxins function as active grazing deterrents. When responding to marine Harmful Algal Bloom (HAB) events, bivalves can reject toxic cells to minimize toxin and bioactive extracellular compound (BEC) exposure, or ingest and digest cells, incorporating nutritional components and toxins. Several studies have reported modulation of bivalve hemocyte variables in response to HAB exposure. Hemocytes are specialized cells involved in many functions in... |
| Tipo: Text |
Palavras-chave: Bivalve; Harmful algal blooms (HABs); Pathogen; Hemocyte; Disease. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72401/71346.pdf |
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| Portet, Anaïs; Galinier, Richard; Lassalle, Damien; Faille, Alexandre; Gourbal, Benjamin; Duval, David. |
| Biomphalaria glabrata is one of the snail intermediate hosts of Schistosoma mansoni, the causative agent of intestinal schistosomiasis disease. Numerous molecular studies using comparative approaches between susceptible and resistant snails to S. mansoni infection have helped identify numerous snail key candidates supporting such susceptible/resistant status. The functional approach using RNA interference (RNAi) remains crucial to validate the function of such candidates. CRISPR-Cas systems are still under development in many laboratories, and RNA interference remains the best tool to study B. glabrata snail genetics. Herein, we describe the use of modified small interfering RNA (siRNA) molecules to enhance cell delivery, especially into hemocytes, the... |
| Tipo: Text |
Palavras-chave: Biomphalaria glabrata; Cholesteryl TEG; RNAi interference; BgTEP1; Hemocyte. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79376/81902.pdf |
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| Dubief, Bruno; Nunes, Flavia; Basuyaux, Olivier; Paillard, Christine. |
| Since 1997, populations of the European abalone Haliotis tuberculata suffer mass mortalities attributed to the bacterium Vibrio harveyi. These mortalities occur at the spawning season, when the abalone immune system is depressed, and when temperatures exceed 17 °C, leading to favorable conditions for V. harveyi proliferation. In order to identify mechanisms of disease resistance, experimental successive infections were carried out on two geographically distinct populations: one that has suffered recurrent mortalities (Saint-Malo) and one that has not been impacted by the disease (Molène). Furthermore, abalone surviving these two successive bacterial challenges and uninfected abalone were used for several post-infection analyses. The Saint-Malo population... |
| Tipo: Text |
Palavras-chave: Immunity; Hemocyte; Abalone; Disease; Extracellular products; Immune priming; Vibrio harveyi; Flow cytometry; Resistance; Phagocytosis; Bacterial growth; QPCR; Gill. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00357/46800/46667.pdf |
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| Mitta, Guillaume; Vandenbulcke, Franck; Noel, Thierry; Romestand, Bernard; Beauvillain, Jean Claude; Salzet, Michel; Roch, Philippe. |
| In previous papers, we characterised 3 types of 4-kDa, cysteine-rich, cationic antimicrobial peptides: MGDs (for Mytilus galloprovincialis defensins), mytilins and myticins, which are abundant in the mussel hemocytes. In the present work, me revealed a differential distribution of the cells expressing the different genes. In addition, using confocal and electron microscopy, we confirmed that defensins and mytilins were partially located in different sub-types of circulating hemocytes although the peptides can be located in the same cell, and even in the same granule. We also demonstrated that mytilins exert their microbicidal effect within the cells through the process of phagosome-mytilin granule fusion leading to the co-location of ingested bacteria and... |
| Tipo: Text |
Palavras-chave: Innate immunity; Hemocyte; Mussel; Myticin; Mytilin; Defensin; Antimicrobial. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-413.pdf |
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| SILVA,CLEONOR C.A. DA. |
| Insect phenoloxidase is considered an important mediator in defense reaction against pathogens and parasites. It is present in the hemolymph of most insects as an inactive proenzyme, called prophenoloxidase. In Acheta domesticus (L.) the phenoloxidase activity was studied in the presence of Bacillus subtilis. The bacteria induced the activation of the prophenoloxidase and increased the level of phenoloxidase activity when injected into the hemocoel of A. domesticus nymphs. The level of increase was comparable to those observed in nymphs injected with laminarin, an activator of the proenzyme. Incubating B. subtilis in serum with phenoloxidase activated in vitro and then injecting into the insects accelerated the removal of the bacteria from the hemolymph in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hemolynph; Phenoloxidase; Hemocyte; Defense reaction. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2002000300024 |
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| Carneiro,Maria Elisa; Daemon,Erik. |
| The hemocyte composition of adults of Amblyomma cajennense (Fabricius, 1787) Koch, 1844 adults consisted of three basic cellular types: prahemocyte I (PR I), plasmatocyte (PL) and spherulocyte (ES II). Among the ixodids observed (A. cajennense; A. dissimile Koch, 1844; Rhipicephalus sanguineus Latreille, 1806; Anocentor nitens (Neumann, 1897) Schulze, 1937; Boophilus microplus Canestrini, 1887 and Haemaphysalis sp.) only A. cajennense was different in the adult hemolymph colour. It changed from amber to deep blue as the ixodid age advanced. This fact could be associated with the presence of hemocyanin in the hemolymph and points out the need to develop further investigations about the Ixodidae hemolymph pratein composition as well as the function of all... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ixodidae; Amblyomma; Ixodid; Hemolymph; Hemocyte. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752002000500011 |
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| Registros recuperados: 20 | |
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