Genetic Diversity and Connectivity of the Ostreid Herpesvirus 1 Populations in France: A First Attempt to Phylogeographic Inference for a Marine Mollusc Disease

• Main Authors: Delmotte, Jean, Pelletier, Camille, Morga, Benjamin, Galinier, Richard, Petton, Bruno, Lamy, Jean-Baptiste, Kaltz, Oliver, Avarre, Jean-Christophe, Jacquot, Maude, Montagnani, C., Escoubas, Jean-Michel
• Other Authors: Interactions Hôtes-Pathogènes-Environnements (IHPE), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Unité Adaptation et Santé des Invertébrés Marins (ASIM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), European Project: 678589,H2020,H2020-SFS-2015-2,VIVALDI(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Herpes virus; OsHV-1; phylogeography; non-redundant genomes; genetic diversity; viral spread; minor variations; [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology; [SDV.BID]Life Sciences [q-bio]/Biodiversity; Pacific; Pacific oyster
• Online Access: https://hal.science/hal-03652456; https://hal.science/hal-03652456/document; https://hal.science/hal-03652456/file/Delmotte-2022-VirusEvol-Genetic-ACCEPTED-MANUSCRIT.pdf; https://doi.org/10.1093/ve/veac039

International audience The genetic diversity of viral populations is a key driver of the spatial and temporal diffusion of viruses; yet, studying the diversity of whole genomes from natural populations still remains a challenge. Phylodynamic approaches are commonly used for RNA viruses harboring small genomes, but have only rarely been applied to DNA viruses with larger genomes. Here, we used the Pacific Oyster Mortality Syndrome (POMS, a disease that affects oyster farms around the world) as a model to study the genetic diversity of its causative agent, the Ostreid herpesvirus 1 (OsHV-1) in the three main French oyster-farming areas. Using ultra-deep sequencing on individual moribund oysters and an innovative combination of bioinformatics tools, we de novo assembled 21 OsHV-1 new genomes. Combining quantification of major and minor genetic variations, phylogenetic analysis and ancestral state reconstruction of discrete traits approaches; we assessed the connectivity of OsHV-1 viral populations between the three oyster-farming areas. Our results suggest that the Marennes-Oléron Bay represents the main source of OsHV-1 diversity, from where the virus has dispersed to other farming areas, a scenario consistent with current practices of oyster transfers in France. We demonstrate that phylodynamic approaches can be applied to aquatic DNA viruses to determine how epidemiological, immunological, and evolutionary processes act and potentially interact to shape their diversity patterns.