Molecular analysis of grass carp reovirus HZ08 genome segments 1-3 and 5-6.

A new grass carp reovirus, assigned HZ08, was isolated from a diseased grass carp case during routine examination in Huzhou City, Zhejiang Province, China. The complete nucleotide sequences of genomic segments S1-S3 and S5-S6 were obtained and comprised 3927, 3870, 3753, 2229, and 2030 bp, respectively. Each segment contained a single open reading frame which encoded putative proteins of 143.6, 143.1, 135.9, 80.5, and 68.4 kDa, respectively. Conserved motifs 5' (GUAAUUU...UUCAUC) 3' were found at the ends of each segment. At the amino acid level, HZ08 S1-S3 and S5-S6 showed similarity to the corresponding segments of Aquareovirus. Further phylogenetic analysis using the amino acid sequences of the RNA-dependent RNA polymerases protein encoded by S2 revealed that HZ08 formed a cluster close to the aquareovirus, but was far from the other isolates, which indicated that HZ08 is likely to be a new member of Aquareovirus.