Consulta: creatorFacets:"Bachere, Evelyne"
Registros recuperados: 56
Data/hora: 08/06/2024 16:15:45

Expression, tissue localization and synergy of antimicrobial peptides and proteins in the immune response of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Schmitt, Paulina; De Lorgeril, Julien; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Diverse families of antimicrobial peptides and proteins have been described in oysters. We investigated here how antimicrobials are involved in the immune response against a pathogenic strain of Vibrio splendidus. Oyster antimicrobials were shown to display a wide variety of expression profiles in hemocyte populations and tissues. Oyster defensins are constitutively expressed in specific tissues such as mantle (Cg-Defm) or hemocytes (Cg-Defhs), while Cg-BPI is inducible and Cg-Prp appears down-regulated in hemocytes upon infection. The migratory behavior of hemocytes that express the different antimicrobials was found to be involved in the oyster response to a pathogenic Vibrio infection. Indeed, it contributes to colocalize several antimicrobials that...
Tipo: Text
Palavras-chave: Pacific oyster; Bivalve mollusk; Innate immunity; Bactericidal/permeability-increasing protein; Proline-rich peptide; Defensin; Vibrio.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00093/20382/18267.pdf

Dinoflagelles toxiques sur les cotes francaises pendant l'ete 1983. Extension du dinoflagelle Dinophysis acuminata en Bretagne sud et consequences pour les cultures marines.
Provedor de dados: 5
Autores: Lassus, Patrick; Martin, A; Maggi, Pierre; Berthome, Jean-paul; Langlade, Aime; Bachere, Evelyne.
Discolored waters and human diseases by shellfishes were dominant features of summer 1983 in south coast of Brittany. Vilaine Bay, the most damaged area, was successively affected by brown waters in early June, and diarrhetic intoxications by harvested mussels (July and August), just as DPS producing dinoflagellate (D. acuminata ) reached higher water or mussel guts concentrations than years before. Outspreading in the whole south coast of Brittany and possible relation with hydrological or biological parameters are analyzed.
Tipo: Text
Palavras-chave: Brittany; France; ANE; Protista; Dinophysis acuminata; Shellfish culture; Red tides; Biological poisons; Toxicants.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/1983/publication-1805.pdf

Generation and analysis of a 29,745 unique Expressed Sequence Tags from the Pacific oyster (Crassostrea gigas) assembled into a publicly accessible database: the GigasDatabase
Provedor de dados: 5
Autores: Fleury, Elodie; Huvet, Arnaud; Lelong, Christophe; De Lorgeril, Julien; Boulo, Viviane; Gueguen, Yannick; Bachere, Evelyne; Tanguy, Arnaud; Moraga, Dario; Fabioux, Caroline; Lindeque, Penelope; Shaw, Jenny; Reinhardt, Richard; Prunet, Patrick; Davey, Grace; Lapegue, Sylvie; Sauvage, Christopher; Corporeau, Charlotte; Moal, Jeanne; Gavory, Frederick; Wincker, Patrick; Moreews, Francois; Klopp, Christophe; Mathieu, Michel; Boudry, Pierre; Favrel, Pascal.
Background: Although bivalves are among the most-studied marine organisms because of their ecological role and economic importance, very little information is available on the genome sequences of oyster species. This report documents three large-scale cDNA sequencing projects for the Pacific oyster Crassostrea gigas initiated to provide a large number of expressed sequence tags that were subsequently compiled in a publicly accessible database. This resource allowed for the identification of a large number of transcripts and provides valuable information for ongoing investigations of tissue-specific and stimulus-dependant gene expression patterns. These data are crucial for constructing comprehensive DNA microarrays, identifying single nucleotide...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6770.pdf

The new insights into the oyster antimicrobial defense: Cellular, molecular and genetic view
Provedor de dados: 5
Autores: 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

Mise au point de techniques d'isolement de parasites - Compte rendu d'activité
Provedor de dados: 5
Autores: Grizel, Henri; Bachere, Evelyne; Gagneraud, Sylvie; Audic, Guylaine.
Les recherches faisant l'objet de ce contrat ont porté sur la mise au point de techniques adaptées aux bivalves marins et à l'étude du parasite Bonamia ostreae responsable de la maladie hémocytaire de l'huître plate, Ostrea edulis.
Tipo: Text
Palavras-chave: Pathologie; Huître plate; Ostrea edulis; Bonamia ostreae; Techniques laboratoire.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/00015/12626/9514.pdf

Rapport sur l'étude de la parasitose de l'huitre plate en Bretagne - Etude sur Bonamia Ostreae (Épidémiologie, cycles, essais d'éradication)
Provedor de dados: 5
Autores: Grizel, Henri; Tige, Gilbert; Gadeau, V.; Bachere, Evelyne.
En 1968, un nouveau parasite est mis en évidence par HERRBACB (1971) sur des huîtres plates élevées dans l'Aber Wrach. celui-ci, décrit en 1974 par GRIZEL et coll., sous le nom de Marteilia refringens, s'est propagé progressivement à de nombreux centres d'élevages bretons atteignant le département du Morbihan en 1974 (GRIZEL et coll., 1976). Les premières zones touchées ont été le golfe du Morbihan et la rivière d'Auray, puis en 1975 les rivières de St Philibert et de Crach. La période d'infestation, limitée dans le temps, a lieu durant la période estivale principalement au cours des mois de juillet et août (GRIZEL et coll., 1977). Afin d'enrayer la maladie, et suite aux connaissances acquises, des mesures prophylactiques ont été mises en place, notamment...
Tipo: Text
Ano: 1980
URL: http://archimer.ifremer.fr/doc/00045/15674/13077.pdf

Insight into Invertebrate Defensin Mechanism of Action OYSTER DEFENSINS INHIBIT PEPTIDOGLYCAN BIOSYNTHESIS BY BINDING TO LIPID II
Provedor de dados: 5
Autores: Schmitt, Paulina; Wilmes, Miriam; Pugniere, Martine; Aumelas, Andre; Bachere, Evelyne; Sahl, Hans-georg; Schneider, Tanja; Destoumieux-garzon, Delphine.
Three oyster defensin variants (Cg-Defh1, Cg-Defh2, and Cg-Defm) were produced as recombinant peptides and characterized in terms of activities and mechanism of action. In agreement with their spectrum of activity almost specifically directed against Gram-positive bacteria, oyster defensins were shown here to be specific inhibitors of a bacterial biosynthesis pathway rather than mere membrane-active agents. Indeed, at lethal concentrations, the three defensins did not compromise Staphylococcus aureus membrane integrity but inhibited the cell wall biosynthesis as indicated by the accumulation of the UDP-N-acetylmuramyl-pentapeptide cell wall precursor. In addition, a combination of antagonization assays, thin layer chromatography, and surface plasmon...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12503/9369.pdf

A hemocyanin-derived antimicrobial peptide from the penaeid shrimp adopts an alpha-helical structure that specifically permeabilizes fungal membranes
Provedor de dados: 5
Autores: Petit, Vanessa W.; Rolland, Jean-luc; Blond, Alain; Cazevieille, Chantal; Djediat, Chakib; Peduzzi, Jean; Goulard, Christophe; Bachere, Evelyne; Dupont, Joelle; Destoumieux-garzon, Delphine; Rebuffat, Sylvie.
Background. Hemocyanins are respiratory proteins with multiple functions. In diverse crustaceans hemocyanins can release histidine-rich antimicrobial peptides in response to microbial challenge. In penaeid shrimp, strictly antifungal peptides are released from the C-terminus of hemocyanins.  Methods. The three-dimensional structure of the antifungal peptide PvHCt from Litopenaeus vannamei was determined by NMR. Its mechanism of action against the shrimp pathogen Fusarium oxysporum was investigated using immunochemistry, fluorescence and transmission electron microscopy.  Results. PvHCt folded into an amphipathic α-helix in membrane-mimicking media and displayed a random conformation in aqueous environment. In contact with F. oxysporum, PvHCt bound...
Tipo: Text
Palavras-chave: Antimicrobial peptide; Amphipathic helix; Fungi; Membrane bilayer; Nuclear magnetic resonance (NMR); Fluorescence microscopy.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00301/41202/40362.pdf

Chemiluminescence analysis of the activity of Pecten maximus hemocytes stimulated with zymosan and host-specific Rickettsiales-like organisms
Provedor de dados: 5
Autores: Le Gall, G; Bachere, Evelyne; Mialhe, Eric.
During a study of Rickettsiales-like organisms (RLO) in Pecten maximus gill, histological observation of free RLO in hemoclymph led us to consider interactions between the pathogen and the hemocytes. Firstly, the production of oxygen radicals by hemocytes was established using a luminol-enhanced chemiluminescence method with zymosan axs stimulant. The effects of serveral inhibitors of oxidative metabolism were investigated. The internalization of RLO into hemocytes was demonstrated by electron microscopy but was not related to chemiluminescent activity. The possible involvement of RLO acid phosphatase as the inhibitor of respiratory burst was assessed.
Tipo: Text
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2759.pdf

Whole Transcriptome Profiling of Successful Immune Response to Vibrio Infections in the Oyster Crassostrea gigas by Digital Gene Expression Analysis
Provedor de dados: 5
Autores: De Lorgeril, Julien; Zenagui, Reda; Rosa, Rafael D.; Piquemal, David; Bachere, Evelyne.
The cultivated Pacific oyster Crassostrea gigas has suffered for decades large scale summer mortality phenomenon resulting from the interaction between the environment parameters, the oyster physiological and/or genetic status and the presence of pathogenic microorganisms including Vibrio species. To obtain a general picture of the molecular mechanisms implicated in C. gigas immune responsiveness to circumvent Vibrio infections, we have developed the first deep sequencing study of the transcriptome of hemocytes, the immunocompetent cells. Using Digital Gene Expression (DGE), we generated a transcript catalog of up-regulated genes from oysters surviving infection with virulent Vibrio strains (Vibrio splendidus LGP32 and V. aestuarianus LPi 02/41) compared...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00043/15377/12735.pdf

In vitro culture of mollusc hemocytes. Functional study of burst respiratory activity and analysis of interactions with protozoan and procaryotic pathogens
Provedor de dados: 5
Autores: Boulo, Viviane; Hervio, Dominique; Morvan, Annie; Bachere, Evelyne; Mialhe, Eric.
The chief importance of hemocytes as immune effectors in molluscs has led to develop researches for in vitro culture. The chemiluminescence technique has been used to estimate the phagocytosis capacity of Crassostrea gigas hemocytes according to different culture media and times. Sea water was used as a basic medium. Additives, such as antibiotics or glucose and buffers, such as Tris or Hepes, were tested as weIl as artificial sea water. Hemocyte chemiluminescence activities were recorded at t=o in relation to the medium composition. The highest values were observed when hemocytes were kept in sea water without any modification. Whichever medium, chemiluminescence activity was substantially decreased when hemocytes were previously kept in vitro for a few...
Tipo: Text
Palavras-chave: Crassotrea gigas; Oyster; Bonamia ostreae; Pathogens; Molluscs; Hemocytes.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/acte-4115.PDF

Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts
Provedor de dados: 5
Autores: Akcha, Farida; Barranger, Audrey; Bachere, Evelyne; Berthelin, C. Heude; Piquemal, D.; Alonso, P.; Sallan, R. Rondon; Dimastrogiovanni, G.; Porte, C.; Menard, Dominique; Szczybelski, A.; Benabdelmouna, Abdellah; Auffret, M.; Rouxel, Julien; Burgeot, Thierry.
Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation...
Tipo: Text
Palavras-chave: Oyster; Pesticide; Reproduction; Histology; Gene expression; RT-qPCR; Steroid; Immunity.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00309/41983/83232.pdf

A relationship between antimicrobial peptide gene expression and capacity of a selected shrimp line to survive a Vibrio infection
Provedor de dados: 5
Autores: De Lorgeril, Julien; Gueguen, Yannick; Goarant, Cyrille; Goyard, Emmanuel; Mugnier, Chantal; Fievet, Julie; Piquemal, D; Bachere, Evelyne.
Understanding of antimicrobial defence mechanisms of penaeid shrimp should help in the design of efficient strategies for the management and disease control in aquaculture. In this study, we have specifically analysed the expression in circulating hemocytes of antimicrobial peptides (AMPs) encoding genes, such as PEN2 and PEN3, ALF, crustin, lysozyme and a putative cysteine-rich peptide. We evidenced a relationship between the level of expression of some AMPs and the successful response of the shrimp, Litopenaeus stylirostris, to circumvent a pathogenic Vibrio penaeicida infection. Additionally, significant differences in some AMP transcript amounts are evidenced between control, non-selected shrimp line and the third generation breeding of shrimp selected...
Tipo: Text
Palavras-chave: Real time PCR; Cysteine rich peptide; Crustin; Anti LPS factor; Lysozyme; Penaeidins; Immune response; Vibrio penaeicida; Penaeid; Decapoda; Crustacean.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4524.pdf

Bonamiasis : a model study of diseases in marine molluscs
Provedor de dados: 5
Autores: Grizel, Henri; Mialhe, Eric; Chagot, Dominique; Boulo, Viviane; Bachere, Evelyne.
Research on bonamiasis, an epizootic disease of the edible oyster Ostrea edu/is caused by the protozoan Bonamia ostreae, is discussed in relation to oyster fanning, research technology, epizootiology, and management. Morphological and infectious characteristics of the parasite are described. Recent progress in isolation and purification of the parasite have permitted investigations into host defense mechanisms, parasite infectivity, and the development of a mol1usc-pathogen mode!.
Tipo: Text
Palavras-chave: Epizootic disease; Pathology; Protozoan; Bonamia ostreae; Oysters.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-3120.pdf

Luminol-dependent chemiluminescence by hemocytes of two marine bivalves, Ostrea edulis and Crassostrea gigas
Provedor de dados: 5
Autores: Bachere, Evelyne; Hervio, Dominique; Mialhe, Eric.
Microbicidal phagocytic function and oxidative metabolism of the hemocytes of 2 oyster species, Ostrea edulis and Crassostrea gigas, were investigated using a luminol-enhanced chemiluminescence (technique. First, experimental parameters adapted to marine bivalve hemocytes were established on hemolymph pools of C. gigas in order to obtain qualitatively and quantitatively homogeneous samples and so to perform statistically comparable assays. The use of Modified Alsever Solution (allowed hemocytes to be kept non-aggregated and in a non-stimulated state until starting the assays. A  number of aliquots of 2 X 10(5) hemocytes with an MAS final concentration of 3.5 % showed high chemiluminescent response after stimulation by zymosan particles A particle:hemocyte...
Tipo: Text
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2761.pdf

High polymorphism in big defensin gene expression reveals presence-absence gene variability (PAV) in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Rosa, Rafael D.; Alonso, Pascal; Santini, Adrien; Vergnes, Agnes; Bachere, Evelyne.
We report here the first evidence in an invertebrate, the oyster Crassostrea gigas, of a phenomenon of Presence-Absence Variation (PAV) affecting immune-related genes. We previously evidenced an extraordinary interindividual variability in the basal mRNA abundances of oyster immune genes including those coding for a family of antimicrobial peptides, the big defensins (Cg-BigDef). Cg-BigDef is a diverse family composed of three members: Cg-BigDef1 to -3. Here, we show that besides a high polymorphism in Cg-BigDef mRNA expression, not all individual oysters express simultaneously the three Cg-BigDefs. Moreover, in numerous individuals, no expression of Cg-BigDefs could be detected. Further investigation at the genomic level revealed that in individuals in...
Tipo: Text
Palavras-chave: Mollusk bivalve; Antimicrobial peptide; Polymorphism; Gene copy number variation; High-throughput microfluidic RT-qPCR; Vibrio infection.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00239/35009/33545.pdf

Persistence of infectious pancreatic necrosis virus (IPNV) in scallops Pecten maximus
Provedor de dados: 5
Autores: Mortensen, Stein Hàkon; Bachere, Evelyne; Le Gall, Ghislaine; Mialhe, Eric.
Infectious pancreatic necrosis virus (IPNV), serotype N1 isolated from scallops Pecten maxjmus in Norway, was propagated and used in both inoculation and bath challenge experiments with scallops in vivo. Although virus titers measured in scallop tissues decreased, depuration of virus was not complete during the experimental periods. TPNV was still detectable 11 mo after injection. The highest virus titer was found in the hepatopancreas, but virus was also detectable in other tissues, as well as in the hemolymph. After a bath challenge, uptake of IPNV was shown. Virus was present in hepatopancreas, gonad, kidney, mantle, gill, rectum and in the hemolymph 1 d after the uptake. The titer was highest in the hepatopancreas where virus was detectable at the end...
Tipo: Text
Ano: 1992
URL: http://archimer.ifremer.fr/doc/1992/publication-2767.pdf

Characterization of a defensin from the oyster Crassostrea gigas - Recombinant production, folding, solution structure, antimicrobial activities, and gene expression
Provedor de dados: 5
Autores: Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne.
In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was...
Tipo: Text
Palavras-chave: Crassostrea gigas; Genomic library; Microbiology; Defensin; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2127.pdf

Study of a haplosporidian (Ascetospora), parasitizing the Australian flat oyster Ostrea angasi
Provedor de dados: 5
Autores: Bachere, Evelyne; Chagot, Dominique; Tige, Gilbert; Grizel, Henri.
Considering the epizootics which affect the French stock of flat oysters, Ostrea edulis (Grizel, 1985), trials to introduce an Australian oyster, Ostrea angasi, have been undertaken. The spat produced in a hatchery from breeders imported from Australia were reared in the south ofBrittany and in Normandy (Bougrier et al., 1986). Following mass mortalities (65% of individuals) a haplosporidian was observed in this species. Sporogenesis of the parasite was studied using Iight and electron microscopy.
Tipo: Text
Palavras-chave: Haplosporidian; Parasitology; Pathology; Ostrea angasi; Oysters.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-3112.pdf

Oyster hemocytes express a proline-rich peptide displaying synergistic antimicrobial activity with a defensin
Provedor de dados: 5
Autores: Gueguen, Yannick; Romestand, Bernard; Fievet, Julie; Schmitt, Paulina; Destoumieux Garzon, Delphine; Franck, Vandenbulcke; Philippe, Bulet; Bachere, Evelyne.
A cDNA sequence that encodes a 61-amino acid polypeptide precursor with homologies to proline-rich antimicrobial peptides (AMPs) was identified in the oyster Crassostrea gigas. After release of a hydrophobic signal peptide. the resulting 37-amino acid peptide, Cg-Prp, is composed of an acidic region and a cationic proline-rich region. To evaluate the biological properties of Cg-Prp, multiple proline-rich peptides corresponding to putative processing of the full-length Cg-Prp were synthesized. A limited antimicrobial activity was observed for two of them, which also showed strong synergistic antimicrobial activity with Cg-Def, a defensin from C gigas. To our knowledge, this is the first evidence of synergy between a defensin and another AMP in an...
Tipo: Text
Palavras-chave: Antimicrobial peptide; Mollusk; Synergy; Invertebrate; Innate immunity; Pacific oyster.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6232.pdf

Cg-TIMP, un inhibiteur de metalloproteinase isolé chez Crassostrea gigas : étude de son rôle dans la réparation des lésions et dans les mécanismes de défense
Provedor de dados: 5
Autores: Escoubas, Jean-michel; Montagnani, Caroline; Le Roux, Frédérique; De Lorgeril, Julien; Berthe, Franck; Bachere, Evelyne.
We isolated complementary DNA (Cg-TIMP) from Crassostrea gigas that codes for a protein highly homologous to vertebrate tissue inhibitors of metalloproteinases (TIMPs). In vertebrates, TIMPs are multifunctional proteins that play a key role in extracellular matrix metabolism. They are involved in physiological processes (e.g. embryonic development, damage repair, angiogenesis) and pathological processes (e.g. inflammatory reactions, cancer).
Tipo: Text
Palavras-chave: Proteine; Cg TIMP; ADN; Crassostrea gigas.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3268.pdf

Mortalité du naissain d’Huître creuse Crassostrea gigas dans l’étang de Thau en 2009
Provedor de dados: 5
Autores: Pernet, Fabrice; Barret, Jean; Le Gall, Patrik; Malet, Nathalie; Pastoureaud, Annie; Munaron, Dominique; De Lorgeril, Julien; Bachere, Evelyne; Vaquer, Andre; Huvet, Arnaud; Corporeau, Charlotte; Normand, Julien; Boudry, Pierre; Moal, Jeanne; Quere, Claudie; Quilien, Virgile; Daniel, Jean-yves; Pepin, Jean-francois; Saulnier, Denis; Gonzalez, Jean-louis.
This study was conducted in the Mediterranean area during a mass mortality event of Pacific oyster Crassostrea gigas. The objectives of this work were to increase our understanding of the mass mortality phenomena in Pacific oysters, to identify risky cultivation practises and to propose mitigation strategies. In the first part of this work, we followed environmental parameters of the Thau lagoon in relation with mortality events. Then, we compared mortality and growth parameters of oysters as a function of their origins, their development stages and cultivation sites in relation with energetic, reproduction and pathogens. Finally, we conducted transfer experiments where oysters maintained free of mortality in open sea were transferred in the Thau lagoon...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00002/11354/7927.pdf

Les surmortalités des naissains d’huîtres creuses, Crassostrea gigas : acquis des recherches en 2010
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Baud, Jean-pierre; Pepin, Jean-francois; Benabdelmouna, Abdellah; Soletchnik, Patrick; Lupo, Coralie; Garcia, Celine; Arzul, Isabelle; Boudry, Pierre; Huvet, Arnaud; Pernet, Fabrice; Bachere, Evelyne; Bedier, Edouard; Petton, Bruno; Gaussem, Florian; Stanisiere, Jean-yves; Degremont, Lionel.
Depuis 2008, la filière ostréicole française doit faire face à des surmortalités exceptionnelles des naissains d’huîtres creuses, Crassostrea gigas, (huîtres de moins d’un an) comprises entre 60 et 90% dans tous les sites d’élevage. Des cas de mortalité similaires ont été décrits en Irlande, dans les îles anglo-normandes, au Portugal en 2009 et au Royaume-Uni en 2010. Récemment deux épisodes de mortalité, associés à la présence d’un virus OsHV1 μvar (ou un variant très proche) ont été également décrits en Nouvelle Zélande (décembre 2010) et en Australie (janvier 2011) soulignant la vulnérabilité de la filière ostréicole dans le monde. L’objectif de ce document est de faire un point sur les recherches menées depuis l’apparition de ce phénomène et de...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00033/14423/11719.pdf

Penaeidins, a new family of antimicrobial peptides isolated from the shrimp Penaeus vannamei (Decapoda)
Provedor de dados: 5
Autores: Destoumieux, Delphine; Bulet, Philippe; Loew, Damarys; Van Dorsselaer, Alain; Rodriguez, Jenny; Bachere, Evelyne.
We report here the isolation of three members of a new family of antimicrobial peptides from the hemolymph of shrimps Penaeus vannamei in which immune response has not been experimentally induced. The three molecules display antimicrobial activity against fungi and bacteria with a predominant activity against Gram-positive bacteria. The complete sequences of these peptides were determined by a combination of enzymatic cleavages, Edman degradation, mass spectrometry, and cDNA cloning using a hemocyte cDNA library. The mature molecules (50 and 62 residues) are characterized by an NH2-terminal domain rich in proline residues and a COOH-terminal domain containing three intramolecular disulfide bridges. One of these molecules is post-translationally modified by...
Tipo: Text
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00335/44649/57344.pdf

Stylicins, a new family of antimicrobial peptides from the Pacific blue shrimp Litopenaeus stylirostris
Provedor de dados: 5
Autores: Rolland, Jean-luc; Abdelouahab, Mahdia; Dupont, J.; Lefevre, F.; Bachere, Evelyne; Romestand, Bernard.
The present study reports the characterization of Ls-Stylicin1, a novel antimicrobial peptide from the penaeid shrimp, Litopenoeus stylirostris. The predicted mature peptide of 82 residues is negatively charged (theoretical pl=5.0) and characterized by a proline-rich N-terminal region and a C-terminal region containing 13 cysteine residues. The recombinant Ls-Stylicin1 has been isolated in both monomeric and dimeric forms. Both display strong antifungal activity against Fusarium oxysporum (1.25 mu M &lt; MIC &lt;2.5 mu M), a pathogenic fungus of shrimp, but lower antimicrobial activity against Gram () bacteria, Vibrio sp. (40 mu M &lt; MIC &lt;80 mu M). However, rLs-Stylicin1 is able to agglutinate Vibrio pennaeicidae in vitro in agreement with its potent...
Tipo: Text
Palavras-chave: Ls-Stylicin 1; Peptide; Shrimp; Antifungal; Agglutination; Vibrio.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11387/8094.pdf

Essai de réimplantation de Crassostrea angulata en France. Résistance au chambrage et comportement des hybrides C. angulata - C. gigas
Provedor de dados: 5
Autores: Bougrier, Serge; Raguenes, Gerard; Bachere, Evelyne; Tige, Gilbert; Grizel, Henri.
The inability to rear the oysters C. gigas and O. edulis in certain Brittany waters has prompted us to conduct breeding trials with C. angulata C. gigas and their hybrids. Results have revealed that all the strains tested were sensitive to Tributyl tin (TBT), showing atnormal shell thickness and their growth was lower than C. gigas. In addition, C. angulata was still affected by the presence of the Iridovirus in France.
Tipo: Text
Palavras-chave: TBT; Breeding trials; Hubrids; Crassostrea gigas; Crassostrea angulata; TBT; Chambrage; Croisement; Hybrides; Crassostrea gigas; Crassostrea angulata.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-3102.pdf

Bonamia ostreae (Pichot et Coll., 1979) parasite de l'huître plate : comparaison de deux méthodes de diagnostic
Provedor de dados: 5
Autores: Bachere, Evelyne; Durand, Jean-louis; Tige, Gilbert.
The parasite, Bonamia ostreae, was diagnosed in several South Brittany flat oyster's samples, from gills tissues's prints, stained in May-Grunwald-Giemsa and from corresponding digestive glands sections. The comparaison of results shows quantitative differences relating to the infested oyster's rate, and qualitative differences relating to the early stages of infestation. Gill's print technic seems more intersting for the only Bonamia ostreae diagnosis.
Tipo: Text
Palavras-chave: Pathologie; Parasite; Huître plate; Ostrea edulis; Bonamia ostreae.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/1982/acte-5013.PDF

The major outer membrane protein OmpU of Vibrio splendidus contributes to host antimicrobial peptide resistance and is required for virulence in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Duperthuy, Marylise; Binesse, Johan; Le Roux, Frederique; Romestand, Bernard; Caro, Audrey; Got, Patrice; Givaudan, Alain; Mazel, Didier; Bachere, Evelyne; Destoumieux Garzon, Delphine.
Vibrio splendidus, strain LGP32, is an oyster pathogen associated with the summer mortalities affecting the production of Crassostrea gigas oysters worldwide. Vibrio splendidus LGP32 was shown to resist to up to 10 mu M Cg-Def defensin and Cg-BPI bactericidal permeability increasing protein, two antimicrobial peptides/proteins (AMPs) involved in C. gigas immunity. The resistance to both oyster Cg-Def and Cg-BPI and standard AMPs (polymyxin B, protegrin, human BPI) was dependent on the ompU gene. Indeed, upon ompU inactivation, minimal bactericidal concentrations decreased by up to fourfold. AMP resistance was restored upon ectopic expression of ompU. The susceptibility of bacterial membranes to AMP-induced damages was independent of the ompU-mediated AMP...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11421/8044.pdf

Molecular characterization of two isoforms of defensin from hemocytes of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Gonzalez, Marcelo; Gueguen, Yannick; Desserre, Geraldine; De Lorgeril, Julien; Romestand, Bernard; Bachere, Evelyne.
Antimicrobial peptides (AMPs) are important components of the host innate immune response against microbial invasion. We previously characterized the first AMP from an oyster, a defensin, that was shown to be continuously expressed in the mantle of Crassostrea gigas. In this study, we report the cDNA cloning of two new isoforms of the defensin AMP family (Cg-defh1 and Cg-defh2) from the hemocytes of the oyster. The deduced amino acid sequences reveal two peptides of 73 amino acid residues with a mature portion consisting of 43 amino acid residues. Cy-Defh1 and CyDefh2 share 86% amino acid identity and belong to the "arthropod-molluscs defensin family". qRT-PCR analyses indicate that Cg-defh2 is continuously expressed in the hemocytes of C. gigas. In...
Tipo: Text
Palavras-chave: Defensin; Antimicrobial peptide; Hemocytes; Pacific oyster; Marine invertebrate; Mollusc bivalve.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2331.pdf

NMR Structure of rALF-Pm3, an Anti-Lipopolysaccharide Factor from Shrimp: Model of the Possible Lipid A-Binding Site
Provedor de dados: 5
Autores: Yang, Yinshan; Boze, Helene; Chemardin, Patrick; Padilla, Andre; Moulin, Guy; Tassanakajon, Anchalee; Pugniere, Martine; Roquet, Francoise; Destoumieux Garzon, Delphine; Gueguen, Yannick; Bachere, Evelyne; Aumelas, Andre.
The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and N-15 uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C-34-C-55 disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM(R)-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM(R)-174 complexes indicated rather high molecular sized aggregates, which...
Tipo: Text
Palavras-chave: Ultracentrifugation; Surface plasmon resonance; Septic shock; Structure; NMR; Lipid A; Lipopolysaccharide; Anti lipopolysaccharide factor.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6320.pdf

Evidence of a bactericidal permeability increasing protein in an invertebrate, the Crassostrea gigas Cg-BPI
Provedor de dados: 5
Autores: 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

Evidence in oyster of a plasma extracellular superoxide dismutase which binds LPS
Provedor de dados: 5
Autores: Gonzalez, Marcelo; Romestand, Bernard; Fievet, Julie; Huvet, Arnaud; Lebart, M; Gueguen, Yannick; Bachere, Evelyne.
We have characterized in the oyster Crassostrea gigas an extracellular superoxide dismutase (Cg-EcSOD) which appears to bind lipopolysaccharides (LPS). The protein has been purified from the oyster plasma and identified as a Cu/ZnSOD according to its N-terminal sequencing and biological activity. Cg-EcSOD expression and synthesis are restricted to hemocytes as revealed by in situ hybridization and immunocytochemistry. Cg-EcSOD-expressing hemocytes were seen in blood circulation, in connective tissues, and closely associated to endothelium blood vessels. Cg-EcSOD presents in its amino acid sequence a LPS-binding motif found in the endotoxin receptor CD14 and we show that the protein displays an affinity to Escherichia coli bacteria and with LPS and Lipid A....
Tipo: Text
Palavras-chave: Beta integrin; Oxidative burst; Hemocyte; Crassostrea gigas; Invertebrate; Mollusc bivalve.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3583.pdf

Mise en évidence d'Haplosporidium sp. (Haplosporida - Haplosporidiidae) parasite de l'huître plate Ostrea edulis L.
Provedor de dados: 5
Autores: Bachere, Evelyne; Grizel, Henri.
A new Haplosporidie has been observed in the flat oyster Ostrea edulis from the Mediterranean Sea. Different development stages have been described in light and electron microscopy. The characteristics of the spores and especially the presence of at least four sporal filaments enable us to distinguish this Haplosporidie from those already described in the Atlantic flat oysters. Different haplosporidies have been described in the oyster. Some are known as being pathogenic, Minchinia costalis (Andrews et al., 1962 and 1978; Couch 1967) and Minchinia nelsoni (Haskin et al., 1966; Farley 1968 and 1975), others, identified only recently, are considered as occasional parasites (Van Banning, 1977). During the research conducted on Bonamia ostreae (Pichot et al.,...
Tipo: Text
Palavras-chave: Pathologie; Haplosporidium; Parasite; Ostrea edulis; Huître plate.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/1982/publication-6576.PDF

A hemocyte gene expression signature correlated with predictive capacity of oysters to survive Vibrio infections
Provedor de dados: 5
Autores: Rosa, Rafael Diego; De Lorgeril, Julien; Tailliez, Patrick; Bruno, Roman; Piquemal, David; Bachere, Evelyne.
Background: The complex balance between environmental and host factors is an important determinant of susceptibility to infection. Disturbances of this equilibrium may result in multifactorial diseases as illustrated by the summer mortality syndrome, a worldwide and complex phenomenon that affects the oysters, Crassostrea gigas. The summer mortality syndrome reveals a physiological intolerance making this oyster species susceptible to diseases. Exploration of genetic basis governing the oyster resistance or susceptibility to infections is thus a major goal for understanding field mortality events. In this context, we used high-throughput genomic approaches to identify genetic traits that may characterize inherent survival capacities in C. gigas. Results:...
Tipo: Text
Palavras-chave: Marine invertebrate; Mollusk bivalve; Mass mortality; Transcriptome-wide analysis; Digital gene expression; Microfluidic qPCR; Survival signature; Polymorphism; Gene copy number; Survival predictive biomarkers.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00095/20624/18262.pdf

Functional Divergence in Shrimp Anti-Lipopolysaccharide Factors (ALFs): From Recognition of Cell Wall Components to Antimicrobial Activity
Provedor de dados: 5
Autores: Rosa, Rafael Diego; Vergnes, Agnes; De Lorgeril, Julien; Goncalves, Priscila; Perazzolo, Luciane Maria; Saune, Laure; Romestand, Bernard; Fievet, Julie; Gueguen, Yannick; Bachere, Evelyne; Destoumieux-garzon, Delphine.
Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded beta-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00160/27077/25236.pdf

PenBase, the shrimp antimicrobial peptide penaeidin database: Sequence-based classification and recommended nomenclature
Provedor de dados: 5
Autores: Gueguen, Yannick; Garnier, Julien; Robert, Lorenne; Lefranc, Marie-paule; Mougenot, Isabelle; De Lorgeril, Julien; Janech, Michael; Gross, Paul S.; Warr, Gregory W.; Cuthbertson, Brandon; Barracco, Margherita A.; Bulet, Philippe; Aumelas, Andre&amp;#769;; Yang, Yinshan; Bo, Dong; Xiang, Jianhai; Tassanakajon, Anchalee; Piquemal, Piquemal; Bachere, Evelyne.
Antimicrobial peptides play a major role in innate immunity. The penaeidins, initially characterized from the shrimp Litopenaeus vannamei, are a family of antimicrobial peptides that appear to be expressed in all penaeid shrimps. As of recent, a large number of penaeid nucleotide sequences have been identified from a variety of penaeid shrimp species and these sequences currently reside in several databases under unique identifiers with no nomenclatural continuity. To facilitate research in this field and avoid potential confusion due to a diverse number of nomenclatural designations, we have made a systematic effort to collect, analyse, and classify all the penaeidin sequences available in every database. We have identified a common penaeidin signature...
Tipo: Text
Palavras-chave: Nomenclature; Sequence database; Crustacea; Antimicrobial peptide; Penaeid shrimp; Penaeidin.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2332.pdf

Penaeidins, antimicrobial peptides with chitin-binding activity, are produced and stored in shrimp granulocytes and released after microbial challenge
Provedor de dados: 5
Autores: Destoumieux, Delphine; Munoz, Marcello; Cosseau, Céline; Rodriguez, Jenny; Bulet, Philippe; Comps, Marie-annick; Bachere, Evelyne.
Penaeidins are members of a new family of antimicrobial peptides isolated from a crustacean, which present both Gram-positive antibacterial and antifungal activities. We have studied the localization of synthesis and storage of penaeidins in the shrimp Penaeus vannamei. The distribution of penaeidin transcripts and peptides in various tissues reveals that penaeidins are constitutively synthesized and stored in the shrimp haemocytes. It was shown by immunocytochemistry, at both optical and ultrastructural levels, that the peptides are localized in granulocyte cytoplasmic granules, The expression and localization of penaeidins were further analysed in shrimp subjected to microbial challenge. We found that (1) penaeidin mRNA levels decrease in circulating...
Tipo: Text
Palavras-chave: Crustacean immunity; Penaeid shrimp; Haemocyte; Chitin binding; Antimicrobial peptide.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-412.pdf

Isolement et purification de Marteilia (Protozoa : Ascetospora) parasites de bivalves marins
Provedor de dados: 5
Autores: Mialhe, Eric; Bachere, Evelyne; Le Bec, Claude; Grizel, Henri.
Marteilia (Protozoa: Ascetospora) parasites of Ostrea edulis and Mytilus edulis, have been isolated and purified by an original method. The electron microscopie study of the purified pansporoblasts and spores confirms the integrity of the parasite and shows some new characteristics.
Tipo: Text
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/publication-3223.pdf

Strategy of researches on marine bivalve defense mechanisms
Provedor de dados: 5
Autores: Bachere, Evelyne; Mialhe, Eric; Noel, Thierry; Boulo, Viviane; Hervio, Dominique; Le Gall, Ghyslaine; Morvan, Annie.
Because of the impact of infectious diseases in marine mollusc aquaculture, research has been initially developed in pathology in term of epidemiology and diagnosis. The establishment of basic techniques for in vitro and in vivo studies of host/pathogen interactions and the progresses in the field of cellular and molecular biology have permitted to undertake researches in immunology. Parallel to fundamental interest in understanding defense mecanisms of molluscs against pathogens, applications may be expected for resistant strains obtained by genetic engineering.
Tipo: Text
Palavras-chave: Defense mechanisms; Hosts; Immunology; Pathogens; Crassostrea gigas; Mytilus edulis.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/00038/14884/12207.pdf

Quelles stratégies alternatives aux antibiotiques en aquaculture ?
Provedor de dados: 5
Autores: Nicolas, Jean-louis; Gatesoupe, Joel; Frouel, Stephane; Bachere, Evelyne; Gueguen, Yannick.
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00066/17704/15222.pdf

Use of OmpU porins for attachment and invasion of Crassostrea gigas immune cells by the oyster pathogen Vibrio splendidus
Provedor de dados: 5
Autores: Duperthuy, Marylise; Schmitt, Paulina; Garzon, Edwin; Caro, Audrey; Rosa, Rafael D.; Le Roux, Frederique; Lautredou-audouy, Nicole; Got, Patrice; Romestand, Bernard; De Lorgeril, Julien; Kieffer-jaquinod, Sylvie; Bachere, Evelyne; Destoumieux-garzon, Delphine.
OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for beta-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the...
Tipo: Text
Palavras-chave: Host-pathogen interaction; Innate immunity; Invertebrate; Mollusk; Oxidative burst.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14177/12166.pdf

Exploring the Impact of the Biofloc Rearing System and an Oral WSSV Challenge on the Intestinal Bacteriome of Litopenaeus vannamei
Provedor de dados: 5
Autores: Pilotto, Mariana R.; Goncalves, Andre N. A.; Vieira, Felipe N.; Seifert, Walter Q.; Bachere, Evelyne; Rosa, Rafael D.; Perazzolo, Luciane M.
We provide a global overview of the intestinal bacteriome of Litopenaeus vannamei in two rearing systems and after an oral challenge by the White spot syndrome virus (WSSV). By using a high-throughput 16S rRNA gene sequencing technology, we identified and compared the composition and abundance of bacterial communities from the midgut of shrimp reared in the super-intensive biofloc technology (BFT) and clear seawater system (CWS). The predominant bacterial group belonged to the phylum Proteobacteria, followed by the phyla Bacteroidetes, Actinobacteria, and Firmicutes. Within Proteobacteria, the family Vibrionaceae, which includes opportunistic shrimp pathogens, was more abundant in CWS than in BFT-reared shrimp. Whereas the families Rhodobacteraceae and...
Tipo: Text
Palavras-chave: Biofloc technology (BFT); Penaeid shrimp; Gut microbiota; White spot syndrome virus; 16S rRNA gene sequencing.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56546/58256.pdf

Amélioration génétique expérimentale de la crevette d'élevage de Nouvelle-Calédonie : Sélection d'une population de L. stylirostris résistante à la bactérie pathogène Vibrio penaeicida. Rapport final pour le Ministère de l'Outre-Mer
Provedor de dados: 5
Autores: Goyard, Emmanuel; Goarant, Cyrille; Bachere, Evelyne; De Lorgeril, Julien; Mugnier, Chantal; Ansquer, Dominique; Broutoi, Francis; Brun, Pierre; Imbert, Frederic; Justou, Carole; Maillez, Jean-rene; Patrois, Jacques; Pham, Dominique; Peignon, Jean-marie.
The New-Caledonian shrimp industry is based on the controlled reproduction of the shrimp Litopenaeus stylirostris, a species which was introduced in the 80s. The major difficulty to which the industry has been faced for 10 years is the occurrence of the "syndrome 93", which corresponds to mortality phases when the temperature falls down in April-May-June. This mortality is associated to the pathogenic bacteria Vibrio penaecida and is expressed at different levels which are variable from year ta year and from pond to pond. No resistance to this pathology has been developed spontaneously. This is likely due to the protocole used to rear spawners, which does not allow to implement an efficient selective pressure at each generation  An experimental selection...
Tipo: Text
Palavras-chave: Amélioration génétique; P. styliroslris; Résistance; Syndrome 93; Lyzozyme; Genetic improvement; P. styliroslris; Résistance; Syndrome 93; Lyzozyme.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00109/22020/19643.pdf

Receptivite de trois populations naturelles d'huitres plates Ostrea edulis L. au protozoaire Bonamia ostreae (Pichot et al., 1980).
Provedor de dados: 5
Autores: Bachere, Evelyne; Grizel, Henri.
Experimental infections by inoculation of Bonamia ostreae have been conducted on three flat oysters Ostrea edulis populations coming from wild beds. All of these are disease sensible and the infection rates are respectively 56, 45 and 37% for population from Belle-Isle, La Rochelle and Thau. Receptivity values, compared by Chi-square test, have not revealed significant differences between these three populations.
Tipo: Text
Palavras-chave: MED; France ANE; France Bonamia ostreae Protista Ostrea edulis Bivalvia Parasitic diseases Disease resistance Oyster reefs.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/1983/publication-1827.pdf

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production
Provedor de dados: 5
Autores: Simon-colin, Christelle; Gueguen, Yannick; Bachere, Evelyne; Kouzayha, Achraf; Saulnier, Denis; Gayet, Nicolas; Guezennec, Jean.
Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with...
Tipo: Text
Palavras-chave: Pearl oyster; Exopolysaccharide; Tachyplesin; Antimicrobial.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00275/38599/37128.pdf

Molecular characterization of penaeidins from two Atlantic Brazilian shrimp species, Farfantepenaeus paulensis and Litopenaeus schmitti
Provedor de dados: 5
Autores: Barracco, Margherita; De Lorgeril, Julien; Gueguen, Yannick; Bachere, Evelyne.
We report here the molecular cloning of new members of the penaeidin family from two Atlantic penaeids from Brazil, Litopenaeus schmitti and Farfantepenaeus paulensis. The presence of penaeidins in the granular hemocytes of both shrimps was first evidenced by immunofluorescence, using polyclonal antibodies raised against L. vannamei penaeidin Litvan PEN3-1. cDNAs from the hemocytes of both Brazilian species were obtained by reverse transcription and the sequences encoding penaeidins were amplified by PCR, using primers based on penaeidin consensus sequences. Five penaeidin clones were obtained. According to the international penaeidin classification (PenBase, http://www.penbase.immunaqua.com), the deduced amino acid sequences of two clones from L. schmitti...
Tipo: Text
Palavras-chave: Immuno detection; Molecular cloning; Litopenaeus schmitti; Farfantepenaeus paulensis; Brazilian penaeid shrimps; Hemocytes; Antimicrobial peptides; Penaeidins.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3582.pdf

Big Defensins, a Diverse Family of Antimicrobial Peptides That Follows Different Patterns of Expression in Hemocytes of the Oyster Crassostrea gigas
Provedor de dados: 5
Autores: Rosa, Rafael D.; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Background: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00050/16096/13576.pdf

Cell separation by centrifugal elutriation
Provedor de dados: 5
Autores: Bachere, Evelyne; Chagot, Dominique; Grizel, Henri.
There is an ongoing need to isolate and purify ceIls in bivalve mollusc disease research. Many separation techniques differentiate cells solely by a single factor and usually require additives in the medium that may damage live cells. Centrifugai elutriation is a technique that separates particles by size and density simultaneously and can be conducted in physiological media without additives. Living cells can be separated without chemical damage and, because the procedure can be conducted aseptically, cells can be maintained in vitro after elutriation. A description of the technique, methods to determine flow rates and rotor speeds, and a preliminary separation of oyster hyalinocytes is presented
Tipo: Text
Palavras-chave: Bivalve mollusc; Centrifugal elutriation; Cell separation.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-3118.pdf

Effects of a parental exposure to diuron on Pacific oyster spat methylome
Provedor de dados: 5
Autores: Rondon Sallan, Rodolfo; Grunau, Christoph; Fallet, Manon; Charlemagne, Nicolas; Sussarellu, Rossana; Chaparro, Cristian; Montagnani, Caroline; Mitta, Guillaume; Bachere, Evelyne; Akcha, Farida; Cosseau, Celine.
Environmental epigenetic is an emerging field that studies the cause-effect relationship between environmental factors and heritable trait via an alteration in epigenetic marks. This field has received much attentions since the impact of environmental factors on different epigenetic marks have been shown to be associated with a broad range of phenotypic disorders in natural ecosystems. Chemical pollutants have been shown to affect immediate epigenetic information carriers of several aquatic species but the heritability of the chromatin marks and the consequences for long term adaptation remain open questions. In this work, we investigated the impact of the diuron herbicide on the DNA methylation pattern of spat from exposed Crassotrea gigas genitors. This...
Tipo: Text
Palavras-chave: Crassostrea gigas; Mollusk; DNA methylation; Herbicide; Epigenetic.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00602/71413/69895.pdf

Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field
Provedor de dados: 5
Autores: De Lorgeril, Julien; Escoubas, Jean Michel; Loubiere, Vincent; Pernet, Fabrice; Le Gall, Patrik; Vergnes, Agnes; Aujoulat, Fabien; Jeannot, Jean-luc; Jumas-bilak, Estelle; Got, Patrice; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We...
Tipo: Text
Palavras-chave: Host pathogen interaction; Innate immunity; Invertebrate; Mollusk; In situ mortality; Total bacteria; Crassostrea gigas.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00433/54470/55845.pdf

Ultrastructural study of sporulated instars of a haplosporidian parasitizing the clam Ruditapes decussatus
Provedor de dados: 5
Autores: Chagot, Dominique; Bachere, Evelyne; Ruano, Francisco; Comps, Michel; Grizel, Henri.
In 1951, Vilela pointed out the presence of a haplosporidian parasitizing Ruditapes decussatus from Portuguese waters and created the species Haplosporidium tapetis. Later, a haplosporidian was found in the same species originating from the pound of Thau (France).
Tipo: Text
Palavras-chave: Haplosporidian paratizing; Ruditapes decussatus; Pathology.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/acte-3110.pdf

Bivalve genomics
Provedor de dados: 5
Autores: Saavedra, Carlos; Bachere, Evelyne.
Interest in bivalve genomics has emerged during the last decade, owing to the importance of these organisms in aquaculture and fisheries and to their role in marine environmental science. Knowledge of bivalve genome structure, function and evolution resulting from 20th century "single gene" approaches is limited, but genomic technologies are called to dramatically increase it. Research based on linkage maps, transcriptomics and proteomics is being carried out to study the genetic and molecular bases of traits of interest in bivalve farming industry, mainly disease susceptibility, tolerance to environmental stress, and growth. The Pacific oyster (Crassostrea gigas) is now the focus of an international genome-sequencing consortium. The use of bivalves in...
Tipo: Text
Palavras-chave: Shellfish toxins; Feeding; Stress; Proteomics; Genomics; Bivalves.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1709.pdf

Signature d'expression de gènes, Marqueur prédictif de capacités de survie chez l'huître Crassostrea gigas
Provedor de dados: 5
Autores: Bachere, Evelyne; Degremont, Lionel; Piquemal, David; Roman, Bruno; Noguier, Florian.
Dans le contexte des mortalités massives d'huîtres Crassostrea gigas, les mécanismes moléculaires et les bases génétiques impliquées dans la capacité de survie des huîtres ont été explorées par des approches de génomique à très haut débit. Ces travaux se sont centrés dans un premier temps sur la survie à des infections par des Vibrio virulents pour lesquels des infections expérimentales étaient reproductibles et standardisées en laboratoire. Ces analyses ont conduit à la mise en évidence d'une série de gènes dont l’expression peut prédire la capacité des huîtres à survivre aux infections à vibrios (Rosa et al. 2012). Depuis 2013, les travaux ont permis la validation de la signature de survie qui a pu être corrélée avec les capacités de survie des huîtres...
Tipo: Text
Palavras-chave: Huître creuse; Signature d'expression de gènes; QPCR; Biostatistique; Capacité de survie; Phénotypage; Héritabilité; Pacific oyster; Gene expression signature; QPCR; Biostatistics; Survival capacity; Phenotyping; Heritability.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00434/54551/55925.pdf

Molecular diversity of antimicrobial effectors in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Schmitt, Paulina; Gueguen, Yannick; Desmarais, Erick; Bachere, Evelyne; De Lorgeril, Julien.
Background: To gain insight into the molecular diversity of antimicrobial peptides and proteins in the oyster Crassostrea gigas, we characterized and compared the sequence polymorphism of the antimicrobial peptides (AMPs), Cg-Defensins (Cg-Defs) and Cg-Proline Rich peptide (Cg-Prp), and of the bactericidal permeability increasing protein, Cg-BPI. For that, we analyzed genomic and transcript sequences obtained by specific PCR amplification and in silico searches. Results: High diversification among the three antimicrobial effectors was evidenced by this polymorphism survey. On the basis of sequence phylogenies, each AMP aggregates into clearly defined groups of variants and is the product of a multigenic family displaying a variety of gene structures. In...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00001/11182/6691.pdf

Studies of a European shellfish disease: Bonamia ostreae parasite of the flat oyster Ostrea edulis ; control and treatment. Final Report
Provedor de dados: 5
Autores: Bachere, Evelyne; Ifremer, Unité de Pathologie, Immunologie et Génétique Moléculaire des Invertébrés Marins, F-17390 La Tremblade, France; CEV, Centro Experimental de Vilaxoan, Conselleria de Pesca, Villagarcia de Arosa, Spain; CSIC, Consejo Superior Investigaciones Cientificas, Peira de Bouzas S/N, Avda E. Cabello 636208, Vigo, Spain; UCC, University College Cork, Dept of Zoology Cork, Ireland; FCR, Fisheries Research Center, Abbotstown, Castleknock, Dublin 15, Ireland; US, University of Southampton, Dept of Oceanography Southampton S09 5NH, United Kingdom.
Bonamia ostreae, an intrahemocytic protozoan parasite infecting the oyster Ostrea edulis, is responsible for an endemic disease affecting all intensive breeding areas of European countries. Epidemiological studies showed variable prevalences, 43% in Galicia (Spain), from 6% to 32% in France and 45% in the most important area of Ireland. The impact of oyster transfers, handlings, high densities have been implicated in the disease development but environmental stressors could be more involved than zootechnical methods. The effect of water temperature, salinity and tidal exposure were particulary examined to assess stress induced changes and determine physiological, biochemical and immunological state indices of oyster populations, which will contribute to...
Tipo: Text
Palavras-chave: Disease; Oyster; Ostrea edulis; Parasitology; Bonamia ostreae; Epidemiology.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00273/38383/36713.pdf

Monoclonal antibodies against Bonamia ostreae (Protozoa: Ascetospera), an intrahaemocytic parasite of flat oyster Ostrea edulis (Mollusca : Bivlavia)
Provedor de dados: 5
Autores: Rogier, Hervé; Hervio, Dominique; Boulo, Viviane; Clavies, Christine; Hervaud, Eliane; Bachere, Evelyne; Mialhe, Eric; Grizel, Henri; Pau, Bernard; Paolucci, Francis.
The protozoan Bonamia ostreae (Ascetospora), a paasite of the flat oyster Ostrea edulis, was purified by differential and isopycnic centrifugations. Mice of the strain Balb/c were immunized with purified parasites and hybridomas were prepared by fusion of immunized mouse splenocytes with the mouse myeloma cell line P3-X63-Ag8-653. From the fusion, 12 clones were isolated and saved. The resulting antibodies were characterized with a solid phase radioimmunoassay (RIA). Antibodies from 7 clones reacted only with B. ostreae and not with normal host tissue. Although some of the antibiodies identified. One of these antibodies (20B2-1B12) has an apparent association constant of ca 3 X 10(8) M-1 and bound to a number of different sites on the parasite. These...
Tipo: Text
Palavras-chave: Monoclonal antibodies; Oyster; Ostrea edulis; Bonamia ostreae.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2756.pdf