Publication: Evolutionarily divergent nidovirus with an exceptionally large genome identified in Pacific oysters undergoing mass mortality

Summary: The authors analyzed RNA in oysters from oyster farms in B.C. experiencing mass mortality events as well as in healthy wild oysters. They uncovered a previously unidentified virus in many of the unhealthy and dead oysters: Pacific Oyster Nidovirus 1 (PONV1), which has one of the largest genomes reported for an RNA virus. They found that the virus encodes proteins that are likely involved in novel host-pathogen interactions and represents a potential new family of related large RNA viruses in oysters. While the researchers are still investigating the link between the virus and mortality, this study underscores the importance of exercising caution when transporting oyster spat to prevent spreading disease.