Phylogenetic analysis of a human group B rotavirus WH-1 detected in China in 2002

✍ Scribed by Ji-Hong Yang; Nobumichi Kobayashi; Yuan-Hong Wang; Xuan Zhou; Yan Li; Dun-Jin Zhou; Zhi-Hong Hu; Masaho Ishino; Mohammed M. Alam; Trailokya N. Naik; Muzahed U. Ahmed

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 100 KB
• Volume: 74
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/jmv.20222

✦ Synopsis

Abstract

A human group B rotavirus strain WH‐1 was detected in an adult sporadic case of diarrhea in Wuhan, China in 2002. In this study, the gene sequences of WH‐1 were determined in order to examine the phylogenetic relatedness to other human group B rotaviruses found previously in China (ADRV, in 1982), India (CAL‐1, in 1998), and Bangladesh (Bang373, in 2000), as well as animal viruses, and to estimate the mutation rate of group B rotavirus. VP7 (major outer capsid protein) gene of WH‐1 showed extremely high sequence identity (98.6%) to ADRV and showed relatively high sequence identities to CAL‐1 (92.5%) and Bang373 (92.4%). In contrast, identities to animal (bovine and murine) group B rotaviruses were considerably lower (61–64%). Other gene segments of WH‐1 encoding VP2, VP4, VP6, NSP1–NSP3, and NSP5 also showed high sequence identities to ADRV genes (98–99%), which were generally higher than those to CAL‐1 genes and Bang373 genes (90–95%). However, amino acid sequence identities between WH‐1 and ADRV were almost the same (VP2, VP6, and NSP3), or lower (NSP2) than those between WH‐1 and CAL‐1 (or Bang373). Since rates of synonymous substitution and transition between WH‐1 and ADRV were similar for all the segments analyzed, genetic evolution was considered to have occurred neutrally and at a similar speed in most of the RNA segments. Based on the sequence divergence between WH‐1 and ADRV, the mutation rate in natural condition of human group B rotavirus was estimated as 7.9 × 10^−4^ substitution/site per year. The frequency of synonymous substitution between ADRV and Bang373 was 5.7 times higher than that between ADRV and WH‐1, suggesting that the group B rotaviruses of Indian–Bangladeshi lineage diverged from that of Chinese lineage several decades ago. J. Med. Virol. 74:662–667, 2004. © 2004 Wiley‐Liss, Inc.