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| Registros recuperados: 33 | |
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| Goudenege, David; Travers, Marie-agnes; Lemire, Astrid; Petton, Bruno; Haffner, Philippe; Labreuche, Yannick; Tourbiez, Delphine; Mangenot, Sophie; Calteau, Alexandra; Mazel, Didier; Nicolas, Jean-louis; Jacq, Annick; Le Roux, Frederique. |
| Oyster diseases caused by pathogenic vibrios pose a major challenge to the sustainability of oyster farming. In France since 2012 a disease affecting specifically adult oysters has been associated with the presence of Vibrio aestuarianus. Here, by combining genome comparison, phylogenetic analyses and high throughput infections of strains isolated before or during the recent outbreaks, we show that virulent strains cluster into two V. aestuarianus lineages independently of the sampling dates. The bacterial lethal dose was not different between strains isolated before or after 2012. Hence the emergence of a new highly virulent clonal strain is unlikely. Each lineage comprises nearly identical strains, the majority of them being virulent, suggesting that... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00226/33685/32530.pdf |
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| Robalino, Javier; Chapman, Robert W.; De La Vega, Enrique; O'Leary, Nuala A.; Gorbach, Danielle M.; Du, Zhi-qiang; Rothschild, Max F.; Browdy, Craig L.; Warr, Gregory; Labreuche, Yannick. |
| This chapter contains sections titled: Introduction EST Collection as an Approach to Gene Discovery in Shrimp Medium- to High-Throughput Studies of Differential Expression and Gene Discovery RNAi-Based Applications in Shrimp Aquaculture: From Reverse Genetics to Control of Diseases Markers, Genetic Maps, and Large Insert Genomic Libraries in Shrimp Analytical Challenges in Genomics and Genetics of Shrimp Concluding Remarks Acknowledgments References |
| Tipo: Text |
Palavras-chave: Penaeid shrimp EST collection; Gene discovery gene expression “snapshot” gametogenesis abiotic stress responses differential expression cloning RNAi-based applications; Shrimp targeted gene silencing RNAi; And gene function genetic markers in breeding. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00070/18149/15775.pdf |
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| Bruto, Maxime; Labreuche, Yannick; James, Adele; Piel, Damien; Chenivesse, Sabine; Petton, Bruno; Polz, Martin F.; Le Roux, Frederique. |
| Diseases of marine animals caused by bacteria of the genus Vibrio are on the rise worldwide. Understanding the eco-evolutionary dynamics of these infectious agents is important for predicting and managing these diseases. Yet, compared to Vibrio infecting humans, knowledge of their role as animal pathogens is scarce. Here we ask how widespread is virulence among ecologically differentiated Vibrio populations, and what is the nature and frequency of virulence genes within these populations? We use a combination of population genomics and molecular genetics to assay hundreds of Vibrio strains for their virulence in the oyster Crassostrea gigas, a unique animal model that allows high-throughput infection assays. We show that within the diverse Splendidus... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00452/56370/57967.pdf |
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| Labreuche, Yannick; Lambert, Christophe; Soudant, Philippe; Boulo, Viviane; Huvet, Arnaud; Nicolas, Jean-louis. |
| The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster; Pathogenesis; Vibrio aestuarianus; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2182.pdf |
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| Goudenege, David; Labreuche, Yannick; Krin, Evelyne; Ansquer, Dominique; Mangenot, Sophie; Calteau, Alexandra; Medigue, Claudine; Mazel, Didier; Polz, Martin F.; Le Roux, Frederique. |
| Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively... |
| Tipo: Text |
Palavras-chave: Horizontal gene transfer; Nigritoxin; Phylogeny; Shrimp; Virulence; Vibrio. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27117/28369.pdf |
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| Petton, Bruno; Bruto, Maxime; James, Adele; Labreuche, Yannick; Alunno-bruscia, Marianne; Le Roux, Frederique. |
| Successive disease outbreaks in oyster (Crassostrea gigas) beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 µvar) and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 µvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF) oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe... |
| Tipo: Text |
Palavras-chave: Pacific oysters; Summer mortality; Herpes virus; Vibrio pathogenicity; Experimental infection. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38220/36377.pdf |
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| Beliaeff, Benoit; Chim, Liet; Della Patrona, Luc; Goyard, Emmanuel; Herlin, Jose; Labreuche, Yannick; Walling, Emilie; Ansquer, Dominique; Brun, Pierre; Castex, Mathieu; Coatanea, Denis; Courties, Claude; De Lorgeril, Julien; Dufour, Robert; Frappier, Julie; Goarant, Cyrille; Huber, Matthias; Lemaire, Pierrette; Lemonnier, Hugues; Loubersac, Lionel; Le Roux, Frederique; Lucas, Ronan; Patrois, Jacques; Peignon, Jean-marie; Pham, Dominique; Ramage, Yannick; Soulard, Benoit; Vic, Marlene; Vourey, Elodie; Wabete, Nelly. |
| New Caledonian shrimp farming feasibility studies started in the mid-seventies. Today ca. 2000 tons of Litopenaeus stylirostris, introduced in 1978, are semi-intensively produced each year. Since fifteen years, production has been impacted by two seasonal vibriosis, the “Summer” syndrome caused by Vibrio nigripulchritudo in relation to pond bottom and water column quality, and the “Winter Syndrome” caused by Vibrio penaeicida in relation to drastic temperature drops . With the ambition of elucidating processes possibly leading to mortality outbreaks in ponds, Ifremer has been conducting a research program since 2003 under the DESANS project (2003-2006) and the present DEDUCTION project, equally funded by the South and North Provinces and by the Government... |
| Tipo: Text |
Palavras-chave: Shrimp farming; Technical and scientific support; Vibriosis; Water quality; Pathology; Ecophysiology; Genetics; Zoosanitary monitoring and procedures; Multifactorial and multidisciplinary approach. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00143/25438/23591.pdf |
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| Charme, Marion; Ansquer, Dominique; Vourey, Elodie; Walling, Emilie; Beliaeff, Benoit; Labreuche, Yannick. |
| Experimental infections together with epidemiological studies have shown that pathogenic and non‐pathogenic isolates of V. nigripulchritudo co‐existed in shrimp farm environment (2, 3). Moreover, obtained results also demonstrated that the “summer syndrome”was caused by a single, possibly emerging, cluster of virulent strains. Consequently, it was hypothesized that pathogenic strains of V. nigripulchritudo may persist from one year to the next in the shrimp farm environment and re‐develop inside the grow‐out system at the following rearing cycle (3). This study was therefore aimed at determining whether V. nigripulchritudo isolates may survive, or not, in a shrimp pond bottom soil during a 18‐week drying period. To this end, V.nigripulchritudo mapping was... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00197/30874/29242.pdf |
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| Labreuche, Yannick; Soudant, Philippe; Goncalves, Madeleine; Lambert, Christophe; Nicolas, Jean-louis. |
| Vibrio aestuarianus strain 01/32 was previously shown to be pathogenic to Crassostrea gigas juveniles. To investigate virulence mechanisms of this pathogen, we studied the toxicity to oysters of its extracellular products (ECPs). ECPs displayed lethality to animals, with a LD50 value of 3.3 mu g/g body weight. To determine the oyster cellular immune responses induced by these ECPs, we further examined in vitro their effects on C. gigas hemocytes, using flow cytometric-based hemocyte assays. Treatment of hemolymph with ECPs caused a significant inhibition of hemocyte phagocytosis and adhesive capabilities. In contrast, the pathway of reactive oxygen species production was enhanced by higher ECP concentrations. Exposure of hemocytes to live bacteria induced... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; ECPs; Crassostrea gigas; ROS production; Adhesion; Phagocytosis; Flow cytometry; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1035.pdf |
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| Garnier, Matthieu; Labreuche, Yannick; Garcia, Celine; Robert, Maeva; Nicolas, Jean-louis. |
| A study was conducted to investigate the involvement of bacteria in oyster mortalities during summer. Moribund and apparently healthy oysters were sampled during mortality events along the French coast and in rearing facilities, usually when temperature reached 19 degrees C or higher, and oysters were in the gonadal maturation phase. Hemolymph samples were aseptically withdrawn and submitted to bacteriological analysis. In healthy oysters, bacteria colonized hernolymph at low concentrations depending on the location. In most moribund oysters, bacteria were present in hemolymph and other tissues. These bacterial populations were more often diverse in oysters originating from the open sea than from facilities where animals were generally infected by a single... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2406.pdf |
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| Lambert, Christophe; Soudant, Philippe; Jegaden, Marine; Delaporte, Maryse; Labreuche, Yannick; Moal, Jeanne; Samain, Jean-francois. |
| Bivalve hemocyte competence has been measured by quantifying functional characteristics, including reactive oxygen intermediate (ROI) production after activation with zymosan or phorbol myristate acetate (PMA). However, untreated oyster hemocytes also produce ROI and RNI (reactive nitrogen intermediates) after bleeding even if not stimulated by Zymosan or PMA. Extensive investigation of this parameter by flow cytometry showed that, in vitro, ROI/RNI production by untreated hemocytes maintained in seawater appeared to be independent of both bacterial burden in the serum and non-self particle phagocytosis. ROI/ RNI production in granulocytes was higher than in hyalinocytes and could be intensified when activated by zymosan but not by PMA. Both cell types... |
| Tipo: Text |
Palavras-chave: NO synthase; NADPH oxidase; Flow cytometry; Reactive nitrogen intermediate RNI; Reactive oxygen intermediate ROI; Hemocytes; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3057.pdf |
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| Labreuche, Yannick; Warr, Gregory W.. |
| Over the last decade, RNA interference pathways have emerged in eukaryotes as critical regulators of many diverse biological functions including, among others, transcriptional gene regulation, post-transcriptional gene silencing, heterochromatin remodelling, suppression of transposon activity, and antiviral defences. Although this gene silencing process has been reported to be relatively well conserved in species of different phyla, there are important discrepancies between plants, invertebrates and mammals. In penaeid shrimp, the existence of an intact and functional RNAi machinery is supported by a rapidly growing body of evidence. However, the extent to which this process participates to the host immune responses remains poorly defined in this non-model... |
| Tipo: Text |
Palavras-chave: Shrimp; Innate immune response; In vertebrate immunity; RNA interference; Virus. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00119/23063/20899.pdf |
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| Labreuche, Yannick; O'Leary, Nuala A.; De La Vega, Enrique; Veloso, Artur; Gross, Paul S.; Chapman, Robert W.; Browdy, Craig L.; Warr, Gregory W.. |
| injection of non-specific dsRNA initiates a broad-spectrum innate antiviral immune response in the Pacific white shrimp, Litopenaeus vannamei, however, the receptor involved in recognition of this by-product of viral infections remains unknown. In vertebrates, dsRNA sensing is mediated by a class of Toll-like receptors (TLRs) and results in activation of the interferon system. Because a TLR (lToll) was recently characterized in L. vannamei, we investigated its potential role in dsRNA recognition. We showed that injection of non-specific RNA duplexes did not modify lToll gene expression. A reverse genetic approach was therefore implemented to study its role in vivo. Silencing of lToll did not impair the ability of nonspecific dsRNA to trigger protection... |
| Tipo: Text |
Palavras-chave: Shrimp; Virus; RNA interference; Invertebrate immunity; Innate immune response; Toll like receptor; DSRNA. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6428.pdf |
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| Pauletto, Marianna; Segarra, Amelie; Montagnani, Caroline; Quillien, Virgile; Faury, Nicole; Le Grand, Jacqueline; Miner, Philippe; Petton, Bruno; Labreuche, Yannick; Fleury, Elodie; Fabioux, Caroline; Bargelloni, Luca; Renault, Tristan; Huvet, Arnaud. |
| Double-stranded RNA (dsRNA)-mediated genetic interference (RNAi) is a widely used reverse genetic tool for determining the loss-of-function phenotype of a gene. Here, the possible induction of an immune response by long dsRNA was tested in a marine bivalve (Crassostrea gigas), as well as the specific role of the subunit 2 of the nuclear factor kappa B inhibitor (I kappa B2). This gene is a candidate of particular interest for functional investigations in the context of oyster mass mortality events, as Cg-I kappa B2 mRNA levels exhibited significant variation depending on the amount of ostreid herpesvirus 1 (OsHV-1) DNA detected. In the present study, dsRNAs targeting Cg-I kappa B2 and green fluorescent protein genes were injected in vivo into oysters... |
| Tipo: Text |
Palavras-chave: Anti-viral response; RNA interference; Inhibitor of NF-kappa B; Marine bivalve; Ostreid herpesvirus 1. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00409/52011/52698.pdf |
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| Garnier, Matthieu; Labreuche, Yannick; Nicolas, Jean-louis. |
| Eleven Vibrio isolates invading the hemolymph of live and moribund oysters (Crassostrea gigas) collected in the field and from a hatchery in France, were characterized by a polyphasic approach. Phylogenetic analysis of 16S rRNA, gyrB and toxR genes indicated high homogeneity between these strains and the Vibrio aestuarianus type strain (ATCC35048(T)), and confirmed previous 16S rRNA analysis. In contrast, DNA:DNA hybridization was from 61% to 100%, while phenotypic characters and virulence tests showed a large diversity between the strains. Nevertheless, several common characters allowed the isolates to be distinguished from the reference strain. On the basis of several distinct phenotypic characteristics, it is proposed to establish two subspecies within... |
| Tipo: Text |
Palavras-chave: Polyphasic approach; Summer mortalities; Crassostrea gigas; Pathogen; French isolates; Vibrio aestuarianus. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4961.pdf |
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| Labreuche, Yannick; Chenivesse, Sabine; Jeudy, Alexandra; Le Panse, Sophie; Boulo, Viviane; Ansquer, Dominique; Pages, Sylvie; Givaudan, Alain; Czjzek, Mirjam; Le Roux, Frederique. |
| The Tetraconata (Pancrustacea) concept proposes that insects are more closely related to aquatic crustaceans than to terrestrial centipedes or millipedes. The question therefore arises whether insects have kept crustacean-specific genetic traits that could be targeted by specific toxins. Here we show that a toxin (nigritoxin), originally identified in a bacterial pathogen of shrimp, is lethal for organisms within the Tetraconata and non-toxic to other animals. X-ray crystallography reveals that nigritoxin possesses a new protein fold of the α/β type. The nigritoxin N-terminal domain is essential for cellular translocation and likely encodes specificity for Tetraconata. Once internalized by eukaryotic cells, nigritoxin induces apoptotic cell death through... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00408/51934/52563.pdf |
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| Labreuche, Yannick; Veloso, Artur; De La Vega, Enrique; Gross, Paul S.; Chapman, Robert W.; Browdy, Craig L.; Warr, Gregory W.. |
| Many questions remain unanswered regarding RNAi-based mechanisms and dsRNA-induced antiviral immune responses in penaeid shrimp. In this study, we report the characterization in the white leg shrimp Litopenaeus vannamei of RNAi pathway associated proteins Lv-Ago 1 and Lv-Ago 2, two members of the Argonaute family of proteins, as well as Lv-sid 1, the first shrimp homologue of Sid-1, a membrane channel-forming protein implicated in the cellular import of dsRNA. To decipher their functional implication in RNAi-related phenomena, we monitored their relative expression following stimulation by specific and non-specific RNA duplexes of diverse length. The findings show that the length of small RNA duplexes plays a critical role in the activation of both... |
| Tipo: Text |
Palavras-chave: Shrimp; Litopenaeus vannamei; RNAi; DsRNA; Argonaute; Sid-1; Antiviral immunity. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12652/9587.pdf |
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| Labreuche, Yannick; Pallandre, Laurane; Ansquer, Dominique; Herlin, Jose; Wapotro, Billy; Le Roux, Frederique. |
| Two recurring syndromes threaten the viability of the shrimp industry in New Caledonia, which represents the second largest export business. The "Syndrome 93" is a cold season disease due to Vibrio penaeicida affecting all shrimp farms, while the "Summer Syndrome" is a geographically restricted vibriosis caused by a virulent lineage of Vibrio nigripulchritudo. Microbiological procedures for diagnosis of these diseases are time-consuming and do not have the ability to discriminate the range of virulence potentials of V. nigripulchritudo. In this study, we developed a multiplex PCR method to simultaneously detect these two bacterial species and allow for pathotype discrimination. The detection limits of this assay, that includes an internal amplification... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00063/17398/15169.pdf |
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| Registros recuperados: 33 | |
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