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Isabelle Arzul - One of the best experts on this subject based on the ideXlab platform.
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Bonamia infection in native oysters (Ostrea edulis) in relation to European restoration projects
Aquatic Conservation: Marine and Freshwater Ecosystems, 2020Co-Authors: Hein Sas, Isabelle Arzul, Brenda Deden, Pauline Kamermans, Philine S. E. Zu Ermgassen, Bernadette Pogoda, Joanne Preston, Luke Helmer, Zoë Holbrook, Tom Van Der HaveAbstract:There is a growing effort throughout Europe to restore populations of native oysters (Ostrea edulis), with the ecological objective of enhancing ecosystem biodiversity and resilience. The introduced parasite, Bonamia Ostreae, caused catastrophic mortalities during the 1980s, furthering the decline of this species, and is now present throughout much of the natural range of O. edulis. It is therefore important that restoration attempts avoid further introduction and spread of this parasite, which can cause lethal infections of O. edulis. This article presents a comprehensive overview of the scale and distribution of current infection, transmission pathways, and preventive measure guidelines, focusing on the seas, inlets, and estuaries of north-west Europe, where most ecological restoration attempts for the native European oyster have occurred so far. This is critical information for restoration project planning in which the risk of Bonamia infection must be taken into account.
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is pallial mucus involved in Ostrea edulis defenses against the parasite bonamia Ostreae
Journal of Invertebrate Pathology, 2020Co-Authors: Maria Pradoalvarez, Ophelie Gervais, Sergio Fernandezboo, Stephane Claverol, Cyrielle Lecadet, Christine Dubreuil, Bruno Chollet, Isabelle ArzulAbstract:Abstract Bonamia Ostreae is an intrahemocytic parasite that has been responsible for severe mortalities in the flat oyster Ostrea edulis since the 1970s. The Pacific oyster CrassOstrea gigas is considered to be resistant to the disease and appears to have mechanisms to avoid infection. Most studies carried out on the invertebrate immune system focus on the role of hemolymph, although mucus, which covers the body surface of molluscs, could also act as a barrier against pathogens. In this study, the in vitro effect of mucus from the oyster species Ostrea edulis and C. gigas on B. Ostreae was investigated using flow cytometry. Results showed an increase in esterase activities and mortality rate of parasites exposed to mucus from both oyster species. In order to better understand the potential role of mucus in the defense of the oyster against parasites such as B. Ostreae, liquid chromatography and tandem mass spectrometry were used to describe and compare mucus protein composition from both species. In all oyster species, pallial mucus contains a high level of proteins; however, O. edulis mucus produced a variety of proteins that could be involved in the immune response against the parasite, including Cu/Zn extracellular superoxide dismutase, thioxiredoxin, peroxiredon VI, heat shock protein 90 as well as several hydrolases. Conversely, a different set of antioxidant proteins, hydrolases and stress related proteins were identified in mucus from C. gigas. Our results suggest an innate immunity adaptation of oysters to develop a specific response against their respective pathogens. The mucosal protein composition also provides new insights for further investigations into the immune response in oysters.
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induction of apoptosis by uv in the flat oyster Ostrea edulis
Fish & Shellfish Immunology, 2015Co-Authors: Ophelie Gervais, Tristan Renault, Isabelle ArzulAbstract:Apoptosis is a fundamental feature in the development of many organisms and tissue systems. It is also a mechanism of host defense against environmental stress factors or pathogens by contributing to the elimination of infected cells. Hemocytes play a key role in defense mechanisms in invertebrates and previous studies have shown that physical or chemical stress can increase apoptosis in hemocytes in mollusks. However this phenomenon has rarely been investigated in bivalves especially in the flat oyster Ostrea edulis. The apoptotic response of hemocytes from flat oysters, O. edulis, was investigated after exposure to UV and dexamethasone, two agents known to induce apoptosis in vertebrates. Flow cytometry and microscopy were combined to demonstrate that apoptosis occurs in flat oyster hemocytes. Investigated parameters like intracytoplasmic calcium activity, mitochondrial membrane potential and phosphatidyl-serine externalization were significantly modulated in cells exposed to UV whereas dexamethasone only induced an increase of DNA fragmentation. Morphological changes were also observed on UV-treated cells using fluorescence microscopy and transmission electron microscopy. Our results confirm the apoptotic effect of UV on hemocytes of O. edulis and suggest that apoptosis is an important mechanism developed by the flat oyster against stress factors.
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heat shock protein 90 of bonamia Ostreae characterization and possible correlation with infection of the flat oyster Ostrea edulis
Journal of Eukaryotic Microbiology, 2013Co-Authors: Maria Pradoalvarez, Yann Couraleau, Benjamin Morga, Bruno Chollet, Isabelle ArzulAbstract:In this study, we described the cytosolic HSP90 of Bonamia Ostreae, an intracellular parasite of Ostrea edulis hemocytes. The complete open reading frame was assembled by Rapid Amplification cDNA Ends reactions on cDNA of B. Ostreae-infected hemocytes. HSP90 amplification was corroborated in infected oysters and B. Ostreae purified cells. The functionality of the HSP90, studied by inhibitory assays with radicicol, suggests that this protein may play a role in hemocyte invasion. Our results inform the molecular basis that governs B. Ostreae-O. edulis interactions.
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new insights in flat oyster Ostrea edulis resistance against the parasite bonamia Ostreae
Fish & Shellfish Immunology, 2012Co-Authors: Benjamin Morga, Tristan Renault, Nicole Faury, Isabelle ArzulAbstract:Bonamiosis due to the parasite Bonamia Ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. Ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line expression of an extracellular superoxide dismutase, inhibitor of apoptosis (OeIAP), Fas ligand (OeFas-ligand) and Cathepsin B was significantly increased, whilst cyclophilin B appeared significantly decreased in resistant oysters. Considering their great interest for further studies, the open reading frames of the OeFas-ligand and OeIAP were completely sequenced.
Benjamin Morga - One of the best experts on this subject based on the ideXlab platform.
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heat shock protein 90 of bonamia Ostreae characterization and possible correlation with infection of the flat oyster Ostrea edulis
Journal of Eukaryotic Microbiology, 2013Co-Authors: Maria Pradoalvarez, Yann Couraleau, Benjamin Morga, Bruno Chollet, Isabelle ArzulAbstract:In this study, we described the cytosolic HSP90 of Bonamia Ostreae, an intracellular parasite of Ostrea edulis hemocytes. The complete open reading frame was assembled by Rapid Amplification cDNA Ends reactions on cDNA of B. Ostreae-infected hemocytes. HSP90 amplification was corroborated in infected oysters and B. Ostreae purified cells. The functionality of the HSP90, studied by inhibitory assays with radicicol, suggests that this protein may play a role in hemocyte invasion. Our results inform the molecular basis that governs B. Ostreae-O. edulis interactions.
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new insights in flat oyster Ostrea edulis resistance against the parasite bonamia Ostreae
Fish & Shellfish Immunology, 2012Co-Authors: Benjamin Morga, Tristan Renault, Nicole Faury, Isabelle ArzulAbstract:Bonamiosis due to the parasite Bonamia Ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. Ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line expression of an extracellular superoxide dismutase, inhibitor of apoptosis (OeIAP), Fas ligand (OeFas-ligand) and Cathepsin B was significantly increased, whilst cyclophilin B appeared significantly decreased in resistant oysters. Considering their great interest for further studies, the open reading frames of the OeFas-ligand and OeIAP were completely sequenced.
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Complete mitochondrial DNA sequence of the European flat oyster Ostrea edulis confirms Ostreidae classification
BMC research notes, 2011Co-Authors: Gwenaelle Danic-tchaleu, Benjamin Morga, Sylvie LapegueAbstract:Abstract Background Because of its typical architecture, inheritance and small size, mitochondrial (mt) DNA is widely used for phylogenetic studies. Gene order is generally conserved in most taxa although some groups show considerable variation. This is particularly true in the phylum Mollusca, especially in the Bivalvia. During the last few years, there have been significant increases in the number of complete mitochondrial sequences available. For bivalves, 35 complete mitochondrial genomes are now available in GenBank, a number that has more than doubled in the last three years, representing 6 families and 23 genera. In the current study, we determined the complete mtDNA sequence of O. edulis , the European flat oyster. We present an analysis of features of its gene content and genome organization in comparison with other Ostrea , SaccOstrea and CrassOstrea species. Results The Ostrea edulis mt genome is 16 320 bp in length and codes for 37 genes (12 protein-coding genes, 2 rRNAs and 23 tRNAs) on the same strand. As in other Ostreidae, O. edulis mt genome contains a split of the rrnL gene and a duplication of trnM . The tRNA gene set of O. edulis , Ostrea denselamellosa and CrassOstrea virginica are identical in having 23 tRNA genes, in contrast to Asian oysters, which have 25 tRNA genes (except for C. ariakensis with 24). O. edulis and O. denselamellosa share the same gene order, but differ from other Ostreidae and are closer to CrassOstrea than to SaccOstrea . Phylogenetic analyses reinforce the taxonomic classification of the 3 families Ostreidae, Mytilidae and Pectinidae. Within the Ostreidae family the results also reveal a closer relationship between Ostrea and SaccOstrea than between Ostrea and CrassOstrea . Conclusions Ostrea edulis mitogenomic analyses show a high level of conservation within the genus Ostrea , whereas they show a high level of variation within the Ostreidae family. These features provide useful information for further evolutionary analysis of oyster mitogenomes.
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etude des interactions hote parasite chez l huitre plate Ostrea edulis et son parasite bonamia Ostreae
2010Co-Authors: Benjamin MorgaAbstract:L’histoire de l’ostreiculture francaise met en evidence la fragilite de cette production face a la surexploitation des stocks et l’apparition de maladies. En particulier, la production d’huitre plate, Ostrea edulis, a fortement diminue suite a l’apparition de deux maladies parasitaires dont la bonamiose. Les moyens de lutte contre la bonamiose sont relativement restreints. Ils sont essentiellement bases sur la surveillance de la sante des huitres afin de limiter la dissemination et la propagation de la maladie. Cependant l’utilisation de modeles predictifs de l’evolution de la maladie en zone infectee permettrait d’optimiser la gestion des stocks et minimiser l’impact des agents pathogenes. De plus, le developpement d’animaux resistants a l’infection pourrait permettre de relancer cette production. Ces differentes approches necessitent des outils diagnostiques adaptes, une bonne connaissance du cycle de vie de l’agent pathogene, et, plus particulierement des interactions du parasite avec son hote. Dans ce contexte, l’objectif principal du travail de these propose est de comprendre les interactions entre l’huitre plate Ostrea edulis et son parasite Bonamia Ostreae, et, plus particulierement les bases moleculaires de la resistance au parasite. Dans un premier temps, la realisation d’une banque soustractive d’ADNc a permis d’identifier des ESTs differentiellement exprimees chez des hemocytes en reponse au parasite. L’expression de certains genes dont une galectine a ete mesuree en PCR en temps reel dans le contexte d’infections in vitro. En complement, la reponse cellulaire a ete etudiee par cytometrie en flux et l’infection controlee en microscopie. Ces experiences ont montre une multiplication parasitaire dans les hemocytes au cours du temps associee a une diminution de la production d’EOR et d’esterases. Dans un second temps, il a ete entrepris une etude comparative entre une population d’huitres plates resistantes a la bonamiose et une population naturelle. Les resultats obtenus tendent a montrer qu’une modulation de l’apoptose et une diminution de la phagocytose seraient impliquees dans les mecanismes lies a la resistance a la bonamiose. Ce travail est le premier a etudier la reponse des hemocytes d’huitres plates a une infection par le parasite Bonamia Ostreae au niveau cellulaire et moleculaire.
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Etude des interactions hôte/parasite chez l’huître plate Ostrea edulis et son parasite Bonamia Ostreae
2010Co-Authors: Benjamin MorgaAbstract:L’histoire de l’ostréiculture française met en évidence la fragilité de cette production face à la surexploitation des stocks et l’apparition de maladies. En particulier, la production d’huître plate, Ostrea edulis, a fortement diminué suite à l’apparition de deux maladies parasitaires dont la bonamiose. Les moyens de lutte contre la bonamiose sont relativement restreints. Ils sont essentiellement basés sur la surveillance de la santé des huîtres afin de limiter la dissémination et la propagation de la maladie. Cependant l’utilisation de modèles prédictifs de l’évolution de la maladie en zone infectée permettrait d’optimiser la gestion des stocks et minimiser l’impact des agents pathogènes. De plus, le développement d’animaux résistants à l’infection pourrait permettre de relancer cette production. Ces différentes approches nécessitent des outils diagnostiques adaptés, une bonne connaissance du cycle de vie de l’agent pathogène, et, plus particulièrement des interactions du parasite avec son hôte. Dans ce contexte, l’objectif principal du travail de thèse proposé est de comprendre les interactions entre l’huître plate Ostrea edulis et son parasite Bonamia Ostreae, et, plus particulièrement les bases moléculaires de la résistance au parasite. Dans un premier temps, la réalisation d’une banque soustractive d’ADNc a permis d’identifier des ESTs différentiellement exprimées chez des hémocytes en réponse au parasite. L’expression de certains gènes dont une galectine a été mesurée en PCR en temps réel dans le contexte d’infections in vitro. En complément, la réponse cellulaire a été étudiée par cytométrie en flux et l’infection contrôlée en microscopie. Ces expériences ont montré une multiplication parasitaire dans les hémocytes au cours du temps associée à une diminution de la production d’EOR et d’estérases. Dans un second temps, il a été entrepris une étude comparative entre une population d’huîtres plates résistantes à la bonamiose et une population naturelle. Les résultats obtenus tendent à montrer qu’une modulation de l’apoptose et une diminution de la phagocytose seraient impliquées dans les mécanismes liés à la résistance à la bonamiose. Ce travail est le premier à étudier la réponse des hémocytes d’huîtres plates à une infection par le parasite Bonamia Ostreae au niveau cellulaire et moléculaire.
Tristan Renault - One of the best experts on this subject based on the ideXlab platform.
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induction of apoptosis by uv in the flat oyster Ostrea edulis
Fish & Shellfish Immunology, 2015Co-Authors: Ophelie Gervais, Tristan Renault, Isabelle ArzulAbstract:Apoptosis is a fundamental feature in the development of many organisms and tissue systems. It is also a mechanism of host defense against environmental stress factors or pathogens by contributing to the elimination of infected cells. Hemocytes play a key role in defense mechanisms in invertebrates and previous studies have shown that physical or chemical stress can increase apoptosis in hemocytes in mollusks. However this phenomenon has rarely been investigated in bivalves especially in the flat oyster Ostrea edulis. The apoptotic response of hemocytes from flat oysters, O. edulis, was investigated after exposure to UV and dexamethasone, two agents known to induce apoptosis in vertebrates. Flow cytometry and microscopy were combined to demonstrate that apoptosis occurs in flat oyster hemocytes. Investigated parameters like intracytoplasmic calcium activity, mitochondrial membrane potential and phosphatidyl-serine externalization were significantly modulated in cells exposed to UV whereas dexamethasone only induced an increase of DNA fragmentation. Morphological changes were also observed on UV-treated cells using fluorescence microscopy and transmission electron microscopy. Our results confirm the apoptotic effect of UV on hemocytes of O. edulis and suggest that apoptosis is an important mechanism developed by the flat oyster against stress factors.
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new insights in flat oyster Ostrea edulis resistance against the parasite bonamia Ostreae
Fish & Shellfish Immunology, 2012Co-Authors: Benjamin Morga, Tristan Renault, Nicole Faury, Isabelle ArzulAbstract:Bonamiosis due to the parasite Bonamia Ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. Ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line expression of an extracellular superoxide dismutase, inhibitor of apoptosis (OeIAP), Fas ligand (OeFas-ligand) and Cathepsin B was significantly increased, whilst cyclophilin B appeared significantly decreased in resistant oysters. Considering their great interest for further studies, the open reading frames of the OeFas-ligand and OeIAP were completely sequenced.
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Identification of genes from flat oyster Ostrea edulis as suitable housekeeping genes for quantitative real time PCR.
Fish & Shellfish Immunology, 2010Co-Authors: Benjamin Morga, Nicole Faury, Isabelle Arzul, Tristan RenaultAbstract:Bonamia Ostreae is an intrahaemocytic protozoan affecting Ostrea edulis. The parasite multiplies within haemocytes without being degraded and involves changes in cellular activities. Studies aiming at better understanding host response to a pathogen at the transcriptome levels are frequently based on the use of real time PCR assays, which require some reference genes. However, very few sequence data is available for Ostrea edulis in public databases. Subtracted cDNA libraries were constructed from the Ostrea edulis haemocytes in order to identify genes involved in host reactions against the parasite and quantitative real time PCR assays were developed to study expression of these genes. In this context, identification of reference genes and study of their relative expression stability were required for quantitative real time PCR normalization. The expression of 5 potential candidate reference genes from Ostrea edulis (ie elongation factor 1 alpha (EF1-α), 60S ribosomal protein L5 (L5), glyceraldehyde 3-phosphate-dehydrogenase (GAPDH), polyubiquitin (Ubiq) and β-actin (ACT)) was studied using RNAs extracted from pools of haemocytes in contact with the parasite Bonamia Ostreae and haemocytes alone. Gene expression was quantified by real time PCR and expression stability was analysed with two analytical approaches GeNorm and NormFinder. GAPDH and EF1- were identified as the most stable genes with the GeNorm analysis. Whatever were the tested conditions, EF1- was also found as the most stable gene using Normfinder. The less stable gene was -actin although this gene is commonly used as housekeeping gene in many studies. Our results suggest using GAPDH and EF1- combined as reference genes when studying expression levels in haemocytes of Ostrea edulis. In addition, the complete ORF of these two genes was characterized.
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Identification of genes from flat oyster Ostrea edulis as suitable housekeeping genes for quantitative real time PCR.
Fish & shellfish immunology, 2010Co-Authors: Benjamin Morga, Nicole Faury, Isabelle Arzul, Tristan RenaultAbstract:Bonamia Ostreae is an intrahaemocytic protozoan affecting Ostrea edulis. The parasite multiplies within haemocytes without being degraded and involves changes in cellular activities. Studies aiming at better understanding host response to a pathogen at the transcriptome levels are frequently based on the use of real time PCR assays, which require some reference genes. However, very few sequence data is available for Ostrea edulis in public databases. Subtracted cDNA libraries were constructed from the Ostrea edulis haemocytes in order to identify genes involved in host reactions against the parasite and quantitative real time PCR assays were developed to study expression of these genes. In this context, identification of reference genes and study of their relative expression stability were required for quantitative real time PCR normalization. The expression of 5 potential candidate reference genes from Ostrea edulis (ie elongation factor 1 alpha (EF1-α), 60S ribosomal protein L5 (L5), glyceraldehyde 3-phosphate-dehydrogenase (GAPDH), polyubiquitin (Ubiq) and β-actin (ACT)) was studied using RNAs extracted from pools of haemocytes in contact with the parasite Bonamia Ostreae and haemocytes alone. Gene expression was quantified by real time PCR and expression stability was analysed with two analytical approaches GeNorm and NormFinder. GAPDH and EF1- were identified as the most stable genes with the GeNorm analysis. Whatever were the tested conditions, EF1- was also found as the most stable gene using Normfinder. The less stable gene was -actin although this gene is commonly used as housekeeping gene in many studies. Our results suggest using GAPDH and EF1- combined as reference genes when studying expression levels in haemocytes of Ostrea edulis. In addition, the complete ORF of these two genes was characterized.
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Isolation and culture of heart cells from the European flat oyster,Ostrea edulis
Methods in Cell Science, 1995Co-Authors: Tristan Renault, Géraldine Flaujac, Rose-marie DeuffAbstract:The present study reports a culture technique for heart tissues of the European flat oyster, Ostrea edulis . Heart tissues of flat oysters were dissociated by a trypsin-EDTA treatment and a mechanical action in a Dounce-type homogeneizer. Then, dissociated cells were cultured in three different synthetic media, in pure sea water or in sea water mixed with sterile filtered Japanese oyster, CrassOstrea gigas , hemolymph. All these media were supplemented with 10% of fetal bovine serum. Cultures were grown at 20°C in previously Poly-D-Lysin coated flasks or culture wells. The optimized medium, 3% L15 medium (w/v) in sterile sea water mixed with Japanese oyster hemolymph (1:1) and supplemented with 10% of fetal bovine serum gave the best result. Morphological characterization for the cardiac cultured cells was performed. Thus, cell monolayers of dissociated heart tissues consisted essentially of hemocytes and large granular pigmented cells.
Nicole Faury - One of the best experts on this subject based on the ideXlab platform.
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new insights in flat oyster Ostrea edulis resistance against the parasite bonamia Ostreae
Fish & Shellfish Immunology, 2012Co-Authors: Benjamin Morga, Tristan Renault, Nicole Faury, Isabelle ArzulAbstract:Bonamiosis due to the parasite Bonamia Ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. Ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line expression of an extracellular superoxide dismutase, inhibitor of apoptosis (OeIAP), Fas ligand (OeFas-ligand) and Cathepsin B was significantly increased, whilst cyclophilin B appeared significantly decreased in resistant oysters. Considering their great interest for further studies, the open reading frames of the OeFas-ligand and OeIAP were completely sequenced.
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Identification of genes from flat oyster Ostrea edulis as suitable housekeeping genes for quantitative real time PCR.
Fish & Shellfish Immunology, 2010Co-Authors: Benjamin Morga, Nicole Faury, Isabelle Arzul, Tristan RenaultAbstract:Bonamia Ostreae is an intrahaemocytic protozoan affecting Ostrea edulis. The parasite multiplies within haemocytes without being degraded and involves changes in cellular activities. Studies aiming at better understanding host response to a pathogen at the transcriptome levels are frequently based on the use of real time PCR assays, which require some reference genes. However, very few sequence data is available for Ostrea edulis in public databases. Subtracted cDNA libraries were constructed from the Ostrea edulis haemocytes in order to identify genes involved in host reactions against the parasite and quantitative real time PCR assays were developed to study expression of these genes. In this context, identification of reference genes and study of their relative expression stability were required for quantitative real time PCR normalization. The expression of 5 potential candidate reference genes from Ostrea edulis (ie elongation factor 1 alpha (EF1-α), 60S ribosomal protein L5 (L5), glyceraldehyde 3-phosphate-dehydrogenase (GAPDH), polyubiquitin (Ubiq) and β-actin (ACT)) was studied using RNAs extracted from pools of haemocytes in contact with the parasite Bonamia Ostreae and haemocytes alone. Gene expression was quantified by real time PCR and expression stability was analysed with two analytical approaches GeNorm and NormFinder. GAPDH and EF1- were identified as the most stable genes with the GeNorm analysis. Whatever were the tested conditions, EF1- was also found as the most stable gene using Normfinder. The less stable gene was -actin although this gene is commonly used as housekeeping gene in many studies. Our results suggest using GAPDH and EF1- combined as reference genes when studying expression levels in haemocytes of Ostrea edulis. In addition, the complete ORF of these two genes was characterized.
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Identification of genes from flat oyster Ostrea edulis as suitable housekeeping genes for quantitative real time PCR.
Fish & shellfish immunology, 2010Co-Authors: Benjamin Morga, Nicole Faury, Isabelle Arzul, Tristan RenaultAbstract:Bonamia Ostreae is an intrahaemocytic protozoan affecting Ostrea edulis. The parasite multiplies within haemocytes without being degraded and involves changes in cellular activities. Studies aiming at better understanding host response to a pathogen at the transcriptome levels are frequently based on the use of real time PCR assays, which require some reference genes. However, very few sequence data is available for Ostrea edulis in public databases. Subtracted cDNA libraries were constructed from the Ostrea edulis haemocytes in order to identify genes involved in host reactions against the parasite and quantitative real time PCR assays were developed to study expression of these genes. In this context, identification of reference genes and study of their relative expression stability were required for quantitative real time PCR normalization. The expression of 5 potential candidate reference genes from Ostrea edulis (ie elongation factor 1 alpha (EF1-α), 60S ribosomal protein L5 (L5), glyceraldehyde 3-phosphate-dehydrogenase (GAPDH), polyubiquitin (Ubiq) and β-actin (ACT)) was studied using RNAs extracted from pools of haemocytes in contact with the parasite Bonamia Ostreae and haemocytes alone. Gene expression was quantified by real time PCR and expression stability was analysed with two analytical approaches GeNorm and NormFinder. GAPDH and EF1- were identified as the most stable genes with the GeNorm analysis. Whatever were the tested conditions, EF1- was also found as the most stable gene using Normfinder. The less stable gene was -actin although this gene is commonly used as housekeeping gene in many studies. Our results suggest using GAPDH and EF1- combined as reference genes when studying expression levels in haemocytes of Ostrea edulis. In addition, the complete ORF of these two genes was characterized.
J. Hansson - One of the best experts on this subject based on the ideXlab platform.
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A case of consistent spatial differences in content of diarrhetic shellfish toxins (DST) among three bivalve species : Mytilus edulis, Ostrea edulis and Cerastoderma edule
Journal of Shellfish Research, 2000Co-Authors: Susanne Svensson, Ann-sofi Rehnstam-holm, Carl André, J. HanssonAbstract:Content of diarrhetic .shellfi.sh toxins (DST) was compared among mussels (Mytilus edulis), oysters (Ostrea edulis). and cockles (Cercuioderma edule) at two spatial scales: regions (100 km apart) a ...
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Consistent spatial differences in content of diarrhetic shellfish toxins (DST) among three bivalve species: Mytilus edulis, Ostrea edulis and Cerastoderma edule : N:09
1999Co-Authors: Susanne Svensson, Ann-sofi Rehnstam-holm, J. HanssonAbstract:Consistent spatial differences in content of diarrhetic shellfish toxins (DST) among three bivalve species: Mytilus edulis, Ostrea edulis and Cerastoderma edule : N:09
