Genetic evidence for a unique taxonomic position of white spot syndrome virus of shrimp: Genus Whispovirus

Abstract

White spot syndrome virus (WSSV) is a relatively new agent causing a zoonotic disease in shrimp. Taxonomically this virus is presently an orphaned, floating virus species. WSSV has a unique virion morphology, genome structure, gene content and a distant phylogenetic relationship with other large DNA viruses on the basis of a few conserved genes. The virus lacks overall gene homology with members of the baculovirus genera Nucleopolyhedrovirus and Granulovirus and has a discriminate size of the virion structural proteins. We here propose that WSSV is a representative of a new genus characterized by viruses with an appendage at one end of the virion. For this genus we coin the name whispovirus to accommodate WSSV and related viruses.