Genome sequencing and analysis of kuchijirosho virus identify it as a novel member of the family Amnoonviridae within the order Articulavirales

Abstract

Kuchijirosho virus (KJV) infects the brain of the tiger puffer, Takifugu rubripes, causing lethal disease in cultured populations. Next-generation sequencing identified eight RNA genome segments encoding proteins of 562, 498, 454, 369, 370, 164, 207, and 83 amino acids. BLAST analysis showed that segment 1 encodes a polymerase basic protein 1 (PB1)-like RNA-dependent RNA polymerase homologous to those of members of the family Amnoonviridae. Segment 5 encodes a protein that shows similarity to envelope proteins with two predicted transmembrane domains, suggesting a function as an envelope glycoprotein. The remaining segments could not be annotated due to the limited homology of their encoded proteins to known proteins. These findings indicate that KJV represents a novel lineage within the family Amnoonviridae.