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A Feedback Mechanism to Control Apoptosis Occurs in the Digestive Gland of the Oyster Crassostrea gigas Exposed to the Paralytic Shellfish Toxins Producer Alexandrium catenella ArchiMer
Rolland, Jean-luc; Medhioub, Walid; Vergnes, Agnes; Abi-khalil, Celina; Savar, Veronique; Abadie, Eric; Masseret, Estelle; Amzil, Zouher; Laabir, Mohamed.
To better understand the effect of Paralytic Shellfish Toxins (PSTs) accumulation in the digestive gland of the Pacific oyster, Crassostrea gigas, we experimentally exposed individual oysters for 48 h to a PSTs producer, the dinoflagellate Alexandrium catenella. In comparison to the effect of the non-toxic Alexandrium tamarense, on the eight apoptotic related genes tested, Bax and BI.1 were significantly upregulated in oysters exposed 48 h to A. catenella. Among the five detoxification related genes tested, the expression of cytochrome P450 (CYP1A) was shown to be correlated with toxin concentration in the digestive gland of oysters exposed to the toxic dinoflagellate. Beside this, we observed a significant increase in ROS production, a decrease in...
Tipo: Text Palavras-chave: Shellfish; Toxin; Biomarker; Expression; Phytoplankton.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00225/33606/32003.pdf
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A hemocyanin-derived antimicrobial peptide from the penaeid shrimp adopts an alpha-helical structure that specifically permeabilizes fungal membranes ArchiMer
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
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Aspects moléculaires et biochimiques des stylicines, peptides multifonctionnels identifiés chez la crevette bleue du Pacifique Litopenaeus stylirostris (Crustacea, Decapoda) ArchiMer
Rolland, Jean-luc.
The work reported here was motivated by the economical importance of the pacific blue shrimp Litopenaeus stylirostris farming where high mortality rates are due to bacterial and viral diseases. It consists in the characterisation of two original peptides, the first members of a new multifunctional family of peptides from peneide shrimps, the stylicines. Those two peptides, named stylicines 1 and 2, are negatively charged (pI < 6.0), and characterised by a proline-rich N-terminal region and a C-terminal region containing 13 cysteine residues. Stylicines are synthesized by heamocytes where they are stored within small cytoplasmic granules. To understand the role of these peptides in the immune response of shrimps to a vibrio infection, their recombinant...
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Ano: 2010 URL: http://archimer.ifremer.fr/doc/00024/13558/10612.pdf
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Characterization of a highly thermostable alkaline phosphatase from the euryarchaeon Pyrococcus abyssi ArchiMer
Zappa, Sebastien; Rolland, Jean-luc; Flament, Didier; Gueguen, Yannick; Boudrant, Joseph; Dietrich, Jacques.
This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of the E. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70 degreesC, respectively. Thus far, P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105 degreesC of 18 and 5 h, respectively....
Tipo: Text Palavras-chave: Escherichia coli; Characterization; Isolation; Gene; Alkaline phosphatase; Pyrococcus abyssi; Archaeon.
Ano: 2001 URL: http://archimer.ifremer.fr/doc/2001/publication-1268.pdf
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Effect of Nitrate, Ammonium and Urea on Growth and Pinnatoxin G Production of Vulcanodinium rugosum ArchiMer
Abadie, Eric; Kaci, Lamia; Berteaux, Tom; Hess, Philipp; Sechet, Veronique; Masseret, Estelle; Rolland, Jean-luc; Laabir, Mohamed.
ulcanodinium rugosum, a recently described dinoflagellate species producing a potent neurotoxin (pinnatoxin G), has been identified in French Mediterranean lagoons and was responsible for recurrent episodes of shellfish toxicity detected by mouse bioassay. Until now, the biology and physiology of V. rugosum have not been fully investigated. We studied the growth characteristics and toxicity of a V. rugosum strain (IFR-VRU-01), isolated in the Ingril lagoon in June 2009 (North-Western French Mediterranean Sea). It was cultivated in Enriched Natural Sea Water (ENSW) with organic (urea) and inorganic (ammonium and nitrate) nitrogen, at a temperature of 25 °C and irradiance of 100 μmol/m2·s−1. Results showed that ammonium was assimilated by cells more rapidly...
Tipo: Text Palavras-chave: Vulcanodinium rugosum; Pinnatoxin G; Ingril lagoon; Growth; Nitrogen source.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00276/38748/37290.pdf
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Effets de l'algue toxique Alexandrium catenella sur le système de défense de l'huître creuse Crassostrea gigas ArchiMer
Medhioub, Walid; Duchiron, Marie; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc.
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Ano: 2013 URL: http://archimer.ifremer.fr/doc/00172/28332/26618.pdf
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Exposure to the Neurotoxic Dinoflagellate, Alexandrium catenella, Induces Apoptosis of the Hemocytes of the Oyster, Crassostrea gigas ArchiMer
Medhioub, Walid; Ramondenc, Simon; Vanhove, Audrey; Vergnes, Agnes; Masseret, Estelle; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc.
This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h,...
Tipo: Text Palavras-chave: Shellfish; Toxins; Apoptosis; Gene expression.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00176/28744/27213.pdf
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Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios ArchiMer
Abi-khalil, Celina; Lopez-joven, Carmen; Abadie, Eric; Savar, Veronique; Amzil, Zouher; Laabir, Mohamed; Rolland, Jean-luc.
The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium...
Tipo: Text Palavras-chave: Harmful algae; Environment; Interaction; Pathogens; Defense; Paralytic shellfish toxin.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00309/42016/41308.pdf
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Genetic structure of the common sole (Solea solea) in the Bay of Biscay: Nurseries as units of selection? ArchiMer
Guinand, B; Rolland, Jean-luc; Bonhomme, Francois.
Coastal and estuarine areas in the Bay of Biscay are essential nursery habitats for sole (Solea solea). Using three intronic markers, we investigated patterns of genetic differentiation among cohorts of juveniles (0+, 1+, sub-adults) inhabiting four major nurseries in the Vilaine and Loire river estuaries, the Pertuis d' Antioche strait, and the Gironde estuary. Genetic differentiation was not significant for the age 0- and 1-groups, but was among sub-adult samples (theta(WC) = 0.017; P = 0.031). Hierarchical analyses of genotypic frequencies by nested multivariate ANOVA using redundancy analysis indicated that northern nurseries of Loire and Vilaine rivers had different patterns of genotypic variation with age than southern nurseries of the Pertuis d'...
Tipo: Text Palavras-chave: Selection; Genetic drift; EPIC PCR; Population genetics; Coastal nurseries; Juveniles; Flatfish.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-4299.pdf
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Litopenaeus vannamei stylicins are constitutively produced by hemocytes and intestinal cells and are differentially modulated upon infections ArchiMer
Farias, Natanael Dantas; Falchetti, Marcelo; Matos, Gabriel Machado; Schmitt, Paulina; Barreto, Cairé; Argenta, Nicolas; Rolland, Jean-luc; Bachère, Evelyne; Perazzolo, Luciane Maria; Rosa, Rafael Diego.
Stylicins are anionic antimicrobial host defense peptides (AAMPs) composed of a proline-rich N-terminal region and a C-terminal portion containing 13 conserved cysteine residues. Here, we have increased our knowledge about these unexplored crustacean AAMPs by the characterization of novel stylicin members in the most cultivated penaeid shrimp, Litopenaeus vannamei. We showed that the L. vannamei stylicin family is composed of two members (Lvan-Stylicin1 and Lvan-Stylicin2) encoded by different loci which vary in gene copy number. Unlike the other three gene-encoded antimicrobial peptide families from penaeid shrimp, the expression of Lvan-Stylicins is not restricted to hemocytes. Indeed, they are also produced by the columnar epithelial cells lining the...
Tipo: Text Palavras-chave: Crustacean; Penaeid shrimp; Invertebrate immunity; Antimicrobial peptide; Host defense peptide; Molecular diversity.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00466/57816/60102.pdf
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OsHV-1 countermeasures to the Pacific oyster’s anti-viral response ArchiMer
Green, Timothy J.; Rolland, Jean-luc; Vergnes, Agnes; Raftos, David; Montagnani, Caroline.
The host-pathogen interactions between the Pacific oyster (Crassostrea gigas) and Ostreid herpesvirus type 1 (OsHV-1) are poorly characterised. Herpesviruses are a group of large, DNA viruses that are known to encode gene products that subvert their host’s antiviral response. It is likely that OsHV-1 has also evolved similar strategies as its genome encodes genes with high homology to C. gigas inhibitors of apoptosis (IAPs) and an interferon-stimulated gene (termed CH25H). The first objective of this study was to simultaneously investigate the expression of C. gigas and OsHV-1 genes that share high sequence homology during an acute infection. Comparison of apoptosis-related genes revealed that components of the extrinsic apoptosis pathway (TNF) were...
Tipo: Text Palavras-chave: Crassostrea; Anti-viral response; Apoptosis; Interferon-like; Poly I:C.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00279/39048/37610.pdf
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Oyster Farming, Temperature, and Plankton Influence the Dynamics of Pathogenic Vibrios in the Thau Lagoon ArchiMer
Lopez-joven, Maria-carmen; Rolland, Jean-luc; Haffner, Philippe; Caro, Audrey; Roques, Cecile; Carre, Claire; Travers, Marie-agnes; Abadie, Eric; Laabir, Mohamed; Bonnet, Delphine; Destoumieux-garzon, Delphine.
Vibrio species have been associated with recurrent mass mortalities of juvenile oysters Crassostrea gigas threatening oyster farming worldwide. However, knowledge of the ecology of pathogens in affected oyster farming areas remains scarce. Specifically, there are no data regarding (i) the environmental reservoirs of Vibrio populations pathogenic to oysters, (ii) the environmental factors favoring their transmission, and (iii) the influence of oyster farming on the persistence of those pathogens. This knowledge gap limits our capacity to predict and mitigate disease occurrence. To address these issues, we monitored Vibrio species potentially pathogenic to C. gigas in 2013 and 2014 in the Thau Lagoon, a major oyster farming region in the coastal French...
Tipo: Text Palavras-chave: Vibrio; Shellfish farming; Bivalve mollusks; Mortality outbreak; Phytoplankton; Zooplankton.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00463/57479/59598.pdf
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Paralytic Toxins Accumulation and Tissue Expression of alpha-Amylase and Lipase Genes in the Pacific Oyster Crassostrea gigas Fed with the Neurotoxic Dinoflagellate Alexandrium catenella ArchiMer
Rolland, Jean-luc; Pelletier, Kevin; Masseret, Estelle; Rieuvilleneuve, Fabien; Savar, Veronique; Santini, Adrien; Amzil, Zouher.
The pacific oyster Crassostrea gigas was experimentally exposed to the neurotoxic Alexandrium catenella and a non-producer of PSTs, Alexandrium tamarense (control algae), at concentrations corresponding to those observed during the blooming period. At fixed time intervals, from 0 to 48 h, we determined the clearance rate, the total filtered cells, the composition of the fecal ribbons, the profile of the PSP toxins and the variation of the expression of two a-amylase and triacylglecerol lipase precursor (TLP) genes through semi-quantitative RT-PCR. The results showed a significant decrease of the clearance rate of C. gigas fed with both Alexandrium species. However, from 29 to 48 h, the clearance rate and cell filtration activity increased only in oysters...
Tipo: Text Palavras-chave: Crassostrea gigas; Alexandrium catenella; PSP toxins; Digestion; Gene expression.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00130/24170/22172.pdf
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Population structure of the common sole (Solea solea) in the Northeastern Atlantic and the Mediterranean Sea: revisiting the divide with EPIC markers ArchiMer
Rolland, Jean-luc; Bonhomme, Francois; Lagardere, Francoise; Hassan, M; Guinand, Bruno.
Spatial and temporal population genetic structures of the common sole, Solea solea, were studied in Northeastern Atlantic and Mediterranean Sea populations, using three polymorphic exon-primed intron-crossing (EPIC) markers. Results demonstrated significant multilocus differentiation among Eastern Mediterranean and a group composed by Western Mediterranean and Atlantic populations (theta = 0.150, P < 0.001), but also suggested unrecorded genetic differentiation of the Adriatic Sea population. No pattern of isolation-by-distance was recorded across the range covered by sampling, from the Kattegat to the Aegean Sea. Conversely to genetically structured Mediterranean populations, Atlantic populations ranging from Denmark to Portugal could be considered as...
Tipo: Text Palavras-chave: Marine fish; Genetic structure; Introns; Common sole.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2400.pdf
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Stylicins, a new family of antimicrobial peptides from the Pacific blue shrimp Litopenaeus stylirostris ArchiMer
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 < MIC <2.5 mu M), a pathogenic fungus of shrimp, but lower antimicrobial activity against Gram () bacteria, Vibrio sp. (40 mu M < MIC <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
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The paralytic shellfish toxin, saxitoxin, enters the cytoplasm and induces apoptosis of oyster immune cells through a caspase-dependent pathway ArchiMer
Abikhalil, Celina; Finkelstein, Darren S.; Conejero, Genevieve; Du Bois, Justin; Destoumieux-garzon, Delphine; Rolland, Jean-luc.
Exposure of the toxin-producing dinoflagellate Alexandrium catenella (A. catenella) was previously demonstrated to cause apoptosis of hemocytes in the oyster species Crassostrea gigas. In this work, a coumarin-labeled saxitoxin appeared to spread throughout the cytoplasm of the hemocytes. PSTs, including saxitoxin, were also shown to be directly responsible for inducing apoptosis in hemocytes, a process dependent on caspase activation and independent of reactive oxygen species (ROS) production. A series of in vitro labeling and microscopy experiments revealed that STX and analogs there of induced nuclear condensation, phosphatidylserine exposure, membrane permeability, and DNA fragmentation of hemocytes. Unlike in vertebrates, gonyautoxin-5 (GTX5), which...
Tipo: Text Palavras-chave: Shellfish; Toxin; Harmful algae; Phytoplankton.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00391/50272/50905.pdf
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