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| Registros recuperados: 36 | |
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| Picot, Sandy; Morga, Benjamin; Faury, Nicole; Chollet, Bruno; Dégremont, Lionel; Travers, Marie-agnes; Renault, Tristan; Arzul, Isabelle. |
| Macroautophagy is a mechanism that is involved in various cellular processes, including cellular homeostasis and innate immunity. This pathway has been described in organisms ranging in complexity from yeasts to mammals, and recent results indicate that it occurs in the mantle of the Pacific oyster, Crassostrea gigas. However, the autophagy pathway has never been explored in the hemocytes of C. gigas, which are the main effectors of its immune system and thus play a key role in the defence of the Pacific oyster against pathogens. To investigate autophagy in oyster hemocytes, tools currently used to monitor this mechanism in mammals, including flow cytometry, fluorescent microscopy and transmission electron microscopy, were adapted and applied to the... |
| Tipo: Text |
Palavras-chave: Autophagosome; Autophagy; Crassostrea gigas; Flow cytometry; Fluorescence microscopy; Hemocytes; Transmission electron microscopy. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59905/63087.pdf |
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| Jemaa, Mohamed; Morin, Nathalie; Cavelier, Patricia; Cau, Julien; Strub, Jean Marc; Delsert, Claude. |
| Long-lived animals show a non-observable age-related decline in immune defense, which is provided by blood cells that derive from self-renewing stem cells. The oldest living animals are bivalves. Yet, the origin of hemocytes, the cells involved in innate immunity, is unknown in bivalves and current knowledge about mollusk adult somatic stem cells is scarce. Here we identify a population of adult somatic precursor cells and show their differentiation into hemocytes. Oyster gill contains an as yet unreported irregularly folded structure (IFS) with stem-like cells bathing into the hemolymph. BrdU labeling revealed that the stem-like cells in the gill epithelium and in the nearby hemolymph replicate DNA. Proliferation of this cell population was further... |
| Tipo: Text |
Palavras-chave: Hematopoiesis; Adult somatic progenitor cells; Hemocytes; Mollusk; Marine invertebrates. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30802/29172.pdf |
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| Gagnaire, Beatrice; Soletchnik, Patrick; Faury, Nicole; Kerdudou, Nolwenn; Le Moine, Olivier; Renault, Tristan. |
| Internal defence mechanisms of bivalves include the hemocytes which assume several functions. Relationships exist between environmental factors, physiological state of oysters, defence system and pathogens. Hatchery oysters are more and more produced and reared in the field. The characteristics and particularly the defence system of these animals are poorly documented. In this context, two field trials were carried out from May to September 2002 and from April to July 2003 in order to monitor hemocyte parameters of diploid oysters from natural beds and hatchery-produced diploid oysters using flow cytometry. Several hemocyte parameters (cell mortality, granulocyte percentage, phagocytosis, esterase and peroxidase activities) were monitored. For both oyster... |
| Tipo: Text |
Palavras-chave: Hatchery; Natural beds; Diploids; Flow cytometry; Peroxidase activity; Esterase activity; Phagocytosis; Hemocytes; Crassostrea gigas; Pacific oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3119.pdf |
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| Carneiro,Maria Elisa; Daemon,Erik. |
| With the purpose of characterize morphologically the hemocytes of larvae and nymphs of Rhipicephalus sanguineus on different nutritional phases, it was obtained samples of haemolymph were obtained by sectioning the forelegs and collecting the drop there formed. After dried, the samples were fixed by methanol and stained by Giemsa. Microscopical observation resulted in the characterization of five basic cellular types: prohemocytes, plasmatocytes, granulocytes, spherulocytes and oenocytoids. Moreover, undefined cell types, whose morphological patterns didn't have correlation with the characteristics cited for hemocytes, were found in low frequency. The change in the relative composition of the haemolimph was characterized by decrease of the number of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ixodid; Rhipicephalus sanguineus; Hemocytes; Morphology. |
| Ano: 1996 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751996000300010 |
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| 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 |
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| Gagnaire, Beatrice; Duchemin, M; Auffret, Mathieu; Thomas-guyon, Helene; Renault, Tristan. |
| Parameters of hemocyte populations have been considered as relevant indicators of bivalve health and are currently used in immunotoxicological studies. Hemocytes in hemolymph can be collected by puncturing either the pericardial cavity or the adductor muscle sinus with a syringe. Flow cytometry is a methodological approach that is increasingly being used in laboratories for the study of hemocyte parameters in aquatic invertebrates. However, various protocols for hemocyte processing in laboratories equipped with different types of cytometers have been published. In this context, two flow cytometers ( EPICS XL4 (R), Beckman Coulter and FacsCalibur (R), Becton Dickinson) and two sites of hemocyte collection ( pericardial cavity and adductor muscle sinus) were... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Phagocytosis; Hemocytes; Flow cytometry. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3898.pdf |
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| PASSOS,ELIANA M. DOS; WANDERLEY-TEIXEIRA,VALÉRIA; MARQUES,EDMILSON J.; TEIXEIRA,ÁLVARO A.C.; BRAYNER,FÁBIO A.. |
| The present research aimed to elucidate which aspects of immune responses in Diatraea flavipennella are suppressed by the parasitoid Cotesia flavipes, thus, ensuring parasitism success. We investigated the presence of apoptosis in fat body cells through the TUNEL technique. According to the results, reduced levels of nitric oxide and phenoloxidase activity were observed in larvae parasitized for three days, and reduced total number of hemocytes, after three and seven days. An increase in plasmatocytes and decrease in spherulocytes numbers were observed in the differential count on the third day of parasitism. The number of melanized microspheres in parasitized larvae was low and indicated less intense melanization. The ultrastructural analysis confirmed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Encapsulation; Hemocytes; Humoral response; Parasitoid; Sugarcane Moth Borer (Diatraea saccharalis). |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000402013 |
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| Bouilly, Karine; Gagnaire, Beatrice; Bonnard, Marc; Thomas-guyon, Helene; Renault, Tristan; Miramand, Pierre; Lapegue, Sylvie. |
| Pacific oysters, Crassostrea gigas, are commonly reared in estuaries where they are exposed to anthropogenic pollution. Much research has been made on the toxicity of cadmium to aquatic organisms because the compound recurrently contaminates their environment. Our study examined the influence of cadmium on aneuploidy level (lowered chromosome number in a percentage of somatic cells) and hemocyte parameters in C. gigas at different stages of life. Adults and juveniles were exposed to two different concentrations of cadmium. The first concentration applied was equivalent to a peak value found in Marennes-Oleron bay (Charente-Maritime, France; 50 ng L-1) and the second was 10 times higher (500 ng L-1). Exposure to 50 ng L-1 cadmium caused a significant... |
| Tipo: Text |
Palavras-chave: Phenoloxidase; Flow cytometry; Hemocytes; Aneuploidy; Crassostrea gigas; Cadmium. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1687.pdf |
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| Tirape, Ana; Bacque, Coralie; Brizard, Raphael; Vandenbulcke, Franck; Boulo, Viviane. |
| The work presented here reports the expression of immune-related genes during ontogenesis in the oyster Crassostrea gigar. Expression patterns of 18 selected genes showed that RNAs detected in oocytes and 2-4 cell embryos are of maternal origin and that gene transcription starts early after fertilization. The expression patterns of 4 genes (Cg-timp, Cg-tal, Cg-EcSOD and Drac3) suggested that hemocytes appear in the gastrula-trochophore stages. The localization of Cg-tal expression suggested that hematopoietic cells were derived from vessels and/or artery endothelia cells. Moreover, a bacterial challenge affected the level of expression of genes. Indeed, a change in expression levels was observed for Cg-LBP/BPI, Cg-timp, Drac3 and Cg-MyD88 genes in larval... |
| Tipo: Text |
Palavras-chave: Rel/NF kappa B pathway; Cell proliferation; Hematopoiesis; Mollusk immunity; Hemocytes; Bivalve mollusk. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2612.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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| Benabdelmouna, Abdellah; Saunier, Alice; Ledu, Christophe; Travers, Marie-agnes; Morga, Benjamin. |
| In the context of the abnormal mass mortality of mussels in France since 2014, Flow CytoMetry (FCM) was used in 2015 and 2016 to study the DNA content and cell cycle characteristics of hemic circulating cells collected from 2000 mussels. The mussels were sampled from 12 wild and cultivated blue mussels stocks distributed along the French Atlantic coast from the south Brittany to Pertuis Charentais areas. During these surveys, various genetic abnormalities were frequently detected, and ploidy characteristics revealed contrasting profiles that corresponded to respective contrasting sanitary status, i.e. healthy mussels with high cytogenetic quality (HCQ) versus diseased mussels with low cytogenetic quality (LCQ). In the present work, FCM and hemocytology... |
| Tipo: Text |
Palavras-chave: Mussels; Hemocytes; Flow cytometry; Hemocytology; Cytogenetic quality; Neoplasia. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00455/56623/58443.pdf |
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| 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 |
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| Registros recuperados: 36 | |
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