The Aquareovirus Infection and Replication

Abstract

Knowledge of the aquareovirus replication in the host has been limited to several representative fish reovirus strains. Among them, infection of the grass carp reovirus (GCRV) in grass carp (Ctenopharyngodon idella) cells has been extensively investigated, and therefore, the GCRV is considered as the aquareovirus type stain for elucidating viral replication. In addition, functional characterization of viral replication events through biochemical analysis, transcriptome sequencing, and proteomatic identification have provided systematic insights into understanding the mechanism of the GCRV infection. Current knowledge indicates that the GCRV infection, coupled with cell necrosis and/or apoptosis, is a gradual and integrated process involving virion adsorption, virion entrance, synthesis of viral proteins and genome, virion assembly in inclusion bodies, and nascent virus release. Specifically, mechanisms underlying tissue tropism and the GCRV cell tropism have been clarified in detail to demonstrate the host factors involved in viral attachment and entrance. Furthermore, key viral replication events have been characterized via extensive progress in research on viral proteins involved in viral replication factory formation in the cell cytoplasm. Additionally, non-lytic excretion or intracellular spread of progeny virus dominates the early phase and lytic excretion of virions occurs in the late phase during the GCRV replication in permissive cells.