Biology subjects

Faury, N.

Publications and source records attributed to Faury, N..

3 recordsLinked to original sources

bioRxiv2025

Experimentally mimicking 30 years of Magallana gigas infections with the OsHV-1 virus reveals evolution through positive selection

Ostreid herpesvirus 1 (OsHV-1) poses a significant threat to the global oyster farming industry, causing substantial economic losses due to mortality outbreaks. While OsHV-1 primarily affects the Pacific oyster Magallana gigas, it has also been associated with mortality events in various other host species. Despite progress in understanding OsHV-1 epidemiology, important knowledge gaps remain regarding its evolutionary mechanisms and adaptation to host genetic backgrounds. This study uses experimental evolution and extensive genomic analysis to investigate the dynamics of OsHV-1 evolution in response to oyster host genetic variation. Our results show that genetic mutations, particularly transitions and transversions, play a key role in shaping viral populations, contributing to a trend toward genetic homogenization. Notably, stronger positive selection signals were observed in viral genomes isolated from oyster populations with higher susceptibility, suggesting adaptation of viral genotypes to specific host genetic backgrounds. These findings shed light on the complex evolutionary dynamics of OsHV-1 and its interactions with oyster hosts. Understanding how this virus adapts to host genetic diversity is crucial for developing strategies to mitigate its impact on the oyster farming industry and provides valuable insights into the broader mechanisms of viral evolution in response to host variation.

evolutionary biology↗

bioRxiv2023

Antiviral protection in the Pacific oyster Crassostrea (Magallana) gigas against OsHV-1 infection using UV-inactivated virus

The increase of the frequency and severity of marine diseases affecting farmed marine mollusks are currently threatening the sustainability of this aquaculture sector, with few available prophylactic or therapeutic solutions. Recent advances have shown that the innate immune system of invertebrates can develop memory mechanisms allowing for efficient protection against pathogens. These properties have been called innate immune memory, immune priming or trained immunity. Previous results demonstrated the possibility to elicit antiviral immune priming to protect Pacific oysters against the ostreid herpes virus 1 (OsHV-1), currently plaguing M. gigas production worldwide. Here, we demonstrate that UV-inactivated OsHV-1 is also a potent elicitor of immune priming. Previous exposure to the inactivated virus was able to efficiently protect oysters against OsHV-1, significantly increasing oyster survival. We demonstrate that this exposure blocked viral replication and was able to induce antiviral gene expression potentially involved in controlling the infection. Finally, we show that this phenomenon can persist for at least 3 months, suggesting the induction of innate immune memory mechanisms. This study unravels new ways to train the Pacific oyster immune system that could represent an opportunity to develop new prophylactic strategies to improve health and to sustain the development of marine mollusk aquaculture.

immunology↗

bioRxiv2023

Genetic differentiation and host specialization among OsHV-1 infecting two oyster species in France

AbstractCross-species transmission is a major driver of disease emergence in humans and animals. The Ostreavirus ostreidmalaco1 (OsHV-1) is mainly associated with mortality in the Pacific oyster Magallana gigas, but has also been found in other mollusks, including the European flat oyster Ostrea edulis. This raises questions about OsHV-1 host specificity. This study explored the genetic differentiation of OsHV-1 in M. gigas and O. edulis and the underlying mechanisms. Using high-throughput sequencing, 40 OsHV-1 genomes were obtained from both O. edulis and M. gigas and were analyzed to assess viral diversity, lineage isolation, and cross-species transmission. Comparative genomics, population genetics, phylogenetic and phylodynamic methods revealed that host species significantly influence viral genetic structure. The data suggest that OsHV-1 was introduced in Europe with M. gigas, followed by a cross-species transmission event and divergence into two distinct lineages. Selection signals were identified in genomic regions involved in key viral functions, including host binding, DNA replication, and membrane-associated proteins, indicating possible adaptation to different hosts. Future research should investigate coevolution between OsHV-1 and a broader range of host species using phylogenetic approaches to better understand host-virus dynamics.

evolutionary biology↗