11 research outputs found
RÎle de la température dans l'interaction hußtre creuse / Ostreid Herpesvirus de type 1 : réponses transcriptomiques et métaboliques
Crassostrea gigas is the main species of oyster cultivated in the world. Since 2008, mass mortality events have been affecting oysters aged less than one year old in Europe and Oceania and have been associated with the emergence of the Ostreid herpes virus ÎŒVar (OsHV-1 ÎŒVar). In Europe, these events are seasonal and occur when the seawater temperature is between 16°C and 24°C. In this work, the effect of high temperatures (21°C, 26°C and 29°C) was evaluated on the susceptibility of oysters to OsHV- 1 but also on the virulence of virus.High temperatures (29°C) reduce the susceptibility of oysters to OsHV-1 without altering the infectivity of the virus and its virulence. High temperature could reduce viral infection and virus synthesis by reducing the expression of host genes that encode proteins involved in transcription and translation, catabolism, metabolites transport, and macromolecules biosynthesis. Finally, the induction of apoptosis, ubiquitinylation processes and immune response could lead to the elimination of OsHV-1.Crassostrea gigas est la principale espĂšce dâhuĂźtre cultivĂ©e dans le monde. Depuis 2008, de sĂ©vĂšres Ă©pisodes de mortalitĂ©s affectent les huĂźtres ĂągĂ©es de moins dâun an en Europe et en OcĂ©anie et sont associĂ©es Ă lâĂ©mergence de lâOstreid herpĂšsvirus ÎŒVar (OsHV-1 ÎŒVar). En Europe, ces mortalitĂ©s sont saisonniĂšres et surviennent lorsque la tempĂ©rature de lâeau de mer est comprise entre 16°C et 24°C. Dans le cadre de ce travail, lâeffet des hautes tempĂ©ratures (21°C, 26°C et 29°C) est Ă©valuĂ© sur la sensibilitĂ© des huĂźtres Ă OsHV-1 mais aussi sur la persistance et la virulence du virus. La survie des huĂźtres infectĂ©es maintenues Ă 29°C (86%) est supĂ©rieure Ă la survie des huĂźtres placĂ©es Ă 21°C (52%) et Ă 26°C (43%).Les tempĂ©ratures Ă©levĂ©es (29°C) diminuent la sensibilitĂ© des huĂźtres Ă OsHV-1 sans altĂ©rer l'infectivitĂ© du virus et sa virulence. Lâexposition des huĂźtres infectĂ©es Ă 29°C pourrait rĂ©duire lâexpression des gĂšnes viraux et la synthĂšse de virions par la rĂ©duction de lâexpression de gĂšnes hĂŽtes codant pour des protĂ©ines impliquĂ©es dans la transcription et la traduction, la rĂ©duction de lâexpression de gĂšnes impliquĂ©s dans le catabolisme, le transport des mĂ©tabolites, et synthĂšse de macromolĂ©cules.Finalement, lâinduction conjointe de lâapoptose, des processus dâubiquitinylation et de la rĂ©ponse immunitaire, pourrait permettre lâĂ©limination dâOsHV-1
Effects of temperature on the interaction between Pacific oysters and OsHV-1 : transcriptomic and metabolic responses
Crassostrea gigas est la principale espĂšce dâhuĂźtre cultivĂ©e dans le monde. Depuis 2008, de sĂ©vĂšres Ă©pisodes de mortalitĂ©s affectent les huĂźtres ĂągĂ©es de moins dâun an en Europe et en OcĂ©anie et sont associĂ©es Ă lâĂ©mergence de lâOstreid herpĂšsvirus ÎŒVar (OsHV-1 ÎŒVar). En Europe, ces mortalitĂ©s sont saisonniĂšres et surviennent lorsque la tempĂ©rature de lâeau de mer est comprise entre 16°C et 24°C. Dans le cadre de ce travail, lâeffet des hautes tempĂ©ratures (21°C, 26°C et 29°C) est Ă©valuĂ© sur la sensibilitĂ© des huĂźtres Ă OsHV-1 mais aussi sur la persistance et la virulence du virus. La survie des huĂźtres infectĂ©es maintenues Ă 29°C (86%) est supĂ©rieure Ă la survie des huĂźtres placĂ©es Ă 21°C (52%) et Ă 26°C (43%).Les tempĂ©ratures Ă©levĂ©es (29°C) diminuent la sensibilitĂ© des huĂźtres Ă OsHV-1 sans altĂ©rer l'infectivitĂ© du virus et sa virulence. Lâexposition des huĂźtres infectĂ©es Ă 29°C pourrait rĂ©duire lâexpression des gĂšnes viraux et la synthĂšse de virions par la rĂ©duction de lâexpression de gĂšnes hĂŽtes codant pour des protĂ©ines impliquĂ©es dans la transcription et la traduction, la rĂ©duction de lâexpression de gĂšnes impliquĂ©s dans le catabolisme, le transport des mĂ©tabolites, et synthĂšse de macromolĂ©cules.Finalement, lâinduction conjointe de lâapoptose, des processus dâubiquitinylation et de la rĂ©ponse immunitaire, pourrait permettre lâĂ©limination dâOsHV-1.Crassostrea gigas is the main species of oyster cultivated in the world. Since 2008, mass mortality events have been affecting oysters aged less than one year old in Europe and Oceania and have been associated with the emergence of the Ostreid herpes virus ÎŒVar (OsHV-1 ÎŒVar). In Europe, these events are seasonal and occur when the seawater temperature is between 16°C and 24°C. In this work, the effect of high temperatures (21°C, 26°C and 29°C) was evaluated on the susceptibility of oysters to OsHV- 1 but also on the virulence of virus.High temperatures (29°C) reduce the susceptibility of oysters to OsHV-1 without altering the infectivity of the virus and its virulence. High temperature could reduce viral infection and virus synthesis by reducing the expression of host genes that encode proteins involved in transcription and translation, catabolism, metabolites transport, and macromolecules biosynthesis. Finally, the induction of apoptosis, ubiquitinylation processes and immune response could lead to the elimination of OsHV-1
Effects of temperature on the interaction between Pacific oysters and OsHV-1 : transcriptomic and metabolic responses
Crassostrea gigas is the main species of oyster cultivated in the world. Since 2008, mass mortality events have been affecting oysters aged less than one year old in Europe and Oceania and have been associated with the emergence of the Ostreid herpes virus ÎŒVar (OsHV-1 ÎŒVar). In Europe, these events are seasonal and occur when the seawater temperature is between 16°C and 24°C. In this work, the effect of high temperatures (21°C, 26°C and 29°C) was evaluated on the susceptibility of oysters to OsHV- 1 but also on the virulence of virus.High temperatures (29°C) reduce the susceptibility of oysters to OsHV-1 without altering the infectivity of the virus and its virulence. High temperature could reduce viral infection and virus synthesis by reducing the expression of host genes that encode proteins involved in transcription and translation, catabolism, metabolites transport, and macromolecules biosynthesis. Finally, the induction of apoptosis, ubiquitinylation processes and immune response could lead to the elimination of OsHV-1.Crassostrea gigas est la principale espĂšce dâhuĂźtre cultivĂ©e dans le monde. Depuis 2008, de sĂ©vĂšres Ă©pisodes de mortalitĂ©s affectent les huĂźtres ĂągĂ©es de moins dâun an en Europe et en OcĂ©anie et sont associĂ©es Ă lâĂ©mergence de lâOstreid herpĂšsvirus ÎŒVar (OsHV-1 ÎŒVar). En Europe, ces mortalitĂ©s sont saisonniĂšres et surviennent lorsque la tempĂ©rature de lâeau de mer est comprise entre 16°C et 24°C. Dans le cadre de ce travail, lâeffet des hautes tempĂ©ratures (21°C, 26°C et 29°C) est Ă©valuĂ© sur la sensibilitĂ© des huĂźtres Ă OsHV-1 mais aussi sur la persistance et la virulence du virus. La survie des huĂźtres infectĂ©es maintenues Ă 29°C (86%) est supĂ©rieure Ă la survie des huĂźtres placĂ©es Ă 21°C (52%) et Ă 26°C (43%).Les tempĂ©ratures Ă©levĂ©es (29°C) diminuent la sensibilitĂ© des huĂźtres Ă OsHV-1 sans altĂ©rer l'infectivitĂ© du virus et sa virulence. Lâexposition des huĂźtres infectĂ©es Ă 29°C pourrait rĂ©duire lâexpression des gĂšnes viraux et la synthĂšse de virions par la rĂ©duction de lâexpression de gĂšnes hĂŽtes codant pour des protĂ©ines impliquĂ©es dans la transcription et la traduction, la rĂ©duction de lâexpression de gĂšnes impliquĂ©s dans le catabolisme, le transport des mĂ©tabolites, et synthĂšse de macromolĂ©cules.Finalement, lâinduction conjointe de lâapoptose, des processus dâubiquitinylation et de la rĂ©ponse immunitaire, pourrait permettre lâĂ©limination dâOsHV-1
Temperature modulate disease susceptibility of the Pacific oyster Crassostrea gigas and virulence of the Ostreid herpesvirus type 1
Temperature triggers marine diseases by changing host susceptibility and pathogen virulence. Oyster mortalities associated with the Ostreid herpesvirus type 1 (OsHV-1) have occurred seasonally in Europe when the seawater temperature range reaches 16â24âŻÂ°C. Here we assess how temperature modulates oyster susceptibility to OsHV-1 and pathogen virulence. Oysters were injected with OsHV-1 suspension incubated at 21âŻÂ°C, 26âŻÂ°C and 29âŻÂ°C and were placed in cohabitation with healthy oysters (recipients) at these three temperatures according to a fractional factorial design. Survival was followed for 14âŻd and recipients were sampled for OsHV-1 DNA quantification and viral gene expression. The oysters were all subsequently placed at 21âŻÂ°C to evaluate the potential for virus reactivation, before being transferred to oyster farms to evaluate their long-term susceptibility to the disease. Survival of recipients at 29âŻÂ°C (86%) was higher than at 21âŻÂ°C (52%) and 26âŻÂ°C (43%). High temperature (29âŻÂ°C) decreased the susceptibility of oysters to OsHV-1 without altering virus infectivity and virulence. At 26âŻÂ°C, the virulence of OsHV-1 was enhanced. Differences in survival persisted when the recipients were all placed at 21âŻÂ°C, suggesting that OsHV-1 did not reactivate. Additional oyster mortality followed the field transfer, but the overall survival of oysters infected at 29âŻÂ°C remained higher
The Voltage-Dependent Anion Channel (VDAC) of Pacific Oysters Crassostrea gigas Is Upaccumulated During Infection by the Ostreid Herpesvirus-1 (OsHV-1): an Indicator of the Warburg Effect
WOS:000424459500008International audienceVoltage-dependent anion channel (VDAC) is a key mitochondrial protein. VDAC drives cellular energy metabolism by controlling the influx and efflux of metabolites and ions through the mitochondrial membrane, playing a role in its permeabilization. This protein exerts a pivotal role during the white spot syndrome virus (WSSV) infection in shrimp, through its involvement in a particular metabolism that plays in favor of the virus, the Warburg effect. The Warburg effect corresponds to an atypical metabolic shift toward an aerobic glycolysis that provides energy for rapid cell division and resistance to apoptosis. In the Pacific oyster Crassostrea gigas, the Warburg effect occurs during infection by Ostreid herpesvirus (OsHV-1). At present, the role of VDAC in the Warburg effect, OsHV-1 infection and apoptosis is unknown. Here, we developed a specific antibody directed against C. gigas VDAC. This tool allowed us to quantify the tissue-specific expression of VDAC, to detect VDAC oligomers, and to follow the amount of VDAC in oysters deployed in the field. We showed that oysters sensitive to a mortality event in the field presented an accumulation of VDAC. Finally, we propose to use VDAC quantification as a tool to measure the oyster susceptibility to OsHV-1 depending on its environment
Connecting organic to mineral: How the physiological state of an ecosystem-engineer is linked to its habitat structure
WOS:000464891100006International audienceThe honeycomb worm Sabellaria alveolata is capable of building extensive bioconstructions, including what are currently considered Europe's largest biogenic reefs. The size and volume of these bioconstructions, however, vary greatly, such that not all habitats engineered by S. alveolata may be easily identified as reefs. Given that European environmental legislation protects marine habitats that are classified as "reefs", it is important to identity a clear set of definition criteria. Furthermore, quantifiable and unequivocal criteria are also needed to evaluate the ecological (health) state of these reefs, in order to best monitor and protect them. Here we propose new terminology to describe the physical appearance of these bioconstructions and attempt to link these physical criteria to the physiological state of the tube-building polychaete. We tested whether a bioconstruction displaying outward signs of growth is built by "healthy" worms devoid of physiological stress by analysing three macromolecules (carbohydrates, proteins, lipids), four polar lipid fatty acids, six neutral lipid fatty acid markers and three metabolic enzymes (citrate synthase, catalase and superoxide dismutase). The worms were sampled in bioconstructions of different "Type" (veneer vs. hummock), "Phase" (progradation vs. retrogradation), and "Shore Level" (high shore vs. low shore) at Champeaux in Mont-Saint-Michel Bay, France. Our results show that worms sampled in retrograding reefs (i.e. displaying signs of erosion and colonisation by epibionts such as oysters or mussels), were less physiologically stressed than worms sampled in prograding bioconstructions, possibly due to lower intraspecific competition and hence greater food availability. We therefore suggest management measures should encompass the whole mosaic of biogenic construction Types and Phases. We propose the inclusion of the polar lipid fatty acid arachidonic acid, in combination with the activity of two metabolic enzymes, citrate synthase and superoxide dismutase, as the three key biochemical markers to consider for quantitative information on the physiological state of this particular ecosystem engineer. Our results also revealed the influence of both sex and size on fatty acid and enzyme levels, highlighting the importance of taking into account both these variables when sampling and subsequently pooling individuals by sex and size category for laboratory analyses. Once seasonal and site variation have been addressed, these biochemical indicators could be examined in parallel with S. alveolata bioconstruction physical criteria as part of a European-wide protocol for monitoring ecological status in this potential reef habitat
High temperature induces transcriptomic changes in Crassostrea gigas that hinder progress of ostreid herpesvirus (OsHV-1) and promote survival
International audienceHigh temperature induces transcriptomic changes in Crassostrea gigas that hinders progress of Ostreid herpesvirus (OsHV-1) and promotes survival
Understanding the Dynamic of POMS Infection and the Role of Microbiota Composition in the Survival of Pacific Oysters, Crassostrea gigas
For over a decade, Pacific oyster mortality syndrome (POMS), a polymicrobial disease, induced recurring episodes of massive mortality affecting Crassostrea gigas oysters worldwide. Recent studies evidenced a combined infection of the ostreid herpesvirus (OsHV-1 ÎŒVar) and opportunistic bacteria in affected oysters. However, the role of the oyster microbiota in POMS is not fully understood. While some bacteria can protect hosts from infection, even minor changes to the microbial communities may also facilitate infection and worsen disease severity. Using a laboratory-based experimental infection model, we challenged juveniles from 10 biparental oyster families with previously established contrasted genetically based ability to survive POMS in the field. Combining molecular analyses and 16S rRNA gene sequencing with histopathological observations, we described the temporal kinetics of POMS and characterized the changes in microbiota during infection. By associating the microbiota composition with oyster mortality rate, viral load, and viral gene expression, we were able to identify both potentially harmful and beneficial bacterial amplicon sequence variants (ASVs). We also observed a delay in viral infection resulting in a later onset of mortality in oysters compared to previous observations and a lack of evidence of fatal dysbiosis in infected oysters. Overall, these results provide new insights into how the oyster microbiome may influence POMS disease outcomes and open new perspectives on the use of microbiome composition as a complementary screening tool to determine shellfish health and potentially predict oyster vulnerability to POMS.
IMPORTANCE For more than a decade, Pacific oyster mortality syndrome (POMS) has severely impacted the Crassostrea gigas aquaculture industry, at times killing up to 100% of young farmed Pacific oysters, a key commercial species that is cultivated globally. These disease outbreaks have caused major financial losses for the oyster aquaculture industry. Selective breeding has improved disease resistance in oysters, but some levels of mortality persist, and additional knowledge of the disease progression and pathogenicity is needed to develop complementary mitigation strategies. In this holistic study, we identified some potentially harmful and beneficial bacteria that can influence the outcome of the disease. These results will contribute to advance disease management and aquaculture practices by improving our understanding of the mechanisms behind genetic resistance to POMS and assisting in predicting oyster vulnerability to POMS
The oyster Crassostrea gigas, a new model against cancer
The Warburg effect is one of the hallmarks of cancer cells in humans. It is a true metabolic reprogramming to aerobic glycolysis, allowing cancer cells to meet their particular energy needs for growth, proliferation, and resistance to apoptosis, depending on the microenvironment they encounter within the tumor. We have recently discovered that the Crassostrea gigas oyster can naturally reprogram its metabolism to the Warburg effect. Thus, the oyster becomes a new invertebrate model useful for cancer research. Due to its lifestyle, the oyster C. gigas has special abilities to adapt its metabolism to the extreme changes in the environment in which it is located. The oyster C. gigas is therefore a model of interest to study how the environment can control the Warburg effect under conditions that could not be explored in vertebrate model species.Lâeffet Warburg est lâune des caractĂ©ristiques des cellules cancĂ©reuses chez lâhomme. Câest une vĂ©ritable reprogrammation mĂ©tabolique vers la glycolyse aĂ©robie, permettant aux cellules cancĂ©reuses de satisfaire leurs besoins Ă©nergĂ©tiques en fonction du microenvironnement quâelles rencontrent au sein de la tumeur. De par son mode de vie, lâhuĂźtre Crassostrea gigas possĂšde des capacitĂ©s particuliĂšres afin dâadapter son mĂ©tabolisme aux changements extrĂȘmes du milieu dans lequel elle se trouve. Elle est naturellement capable de reprogrammer son mĂ©tabolisme vers lâeffet Warburg. C. gigas reprĂ©sente ainsi un modĂšle dâintĂ©rĂȘt pour Ă©tudier comment lâenvironnement peut contrĂŽler lâeffet Warburg dans des conditions qui ne pourraient ĂȘtre explorĂ©es chez des espĂšces modĂšles vertĂ©brĂ©s
Harsh intertidal environment enhances metabolism and immunity in oyster (Crassostrea gigas) spat
International audienceThe Pacific oyster Crassostrea gigas is established in the marine intertidal zone, experiencing rapid and highly dynamic environmental changes throughout the tidal cycle. Depending on the bathymetry, oysters face oxygen deprivation, lack of nutrients, and high changes in temperature during alternation of the cycles of emersion/ immersion. Here we showed that intertidal oysters at a bathymetry level of 3 and 5 m delayed by ten days the onset of mortality associated with Pacific Oyster Mortality Syndrome (POMS) as compared to subtidal oysters. Intertidal oysters presented a lower growth but similar energetic reserves to subtidal oysters but induced proteomic changes indicative of a boost in metabolism, inflammation, and innate immunity that may have improved their resistance during infection with the Ostreid herpes virus. Our work highlights that intertidal harsh environmental conditions modify host-pathogen interaction and improve oyster health. This study opens new perspectives on oyster farming for mitigation strategies based on tidal height