Comparison of the RNA polymerase genes of marine birnavirus strains and other birnaviruses |
| |
Authors: | C X Zhang S Suzuki |
| |
Institution: | (1) Centre for Marine Environmental Studies, Ehime University, Ehime, Japan, JP;(2) Laboratory of Virus Molecular Biology, Institute of Applied Entomology, Zhejiang University, Hangzhou, China, CN |
| |
Abstract: | Summary. The cDNA nucleotide sequence of the genome segment B encoding the VP1 protein, the putative RNA-dependent RNA polymerase
(RdRp), was determined for 5 marine birnavirus (MABV) strains from different host or geographic origins and 1 infectious pancreatic
necrosis virus (IPNV) strain AM-98. Segment B of the IPNV AM-98 strain and 4 MABV strains, Y-6, YT-01A, H1 and NC1, contained
a 2535 bp ORF, which encoded a protein of 845 amino acid residues with a predicted MW of 94.4 kDa. Only the MABV AY-98 RdRp
had 1 amino acid shorter RdRp. Pairwise comparisons were made among our data and 4 other known IPNV sequences. The nucleotide
sequences of the 5 MABV strains were very similar each other, with identities of 98.3–99.7%. The highest divergence of the
nucleotide level was between MABV strains and IPNV SP strain (serotype A2), with 20.4–20.8% divergences in the coding region,
which gave 10.1–11.3% divergence in the amino acid level. The aquabirnavirus RdRp was noticeably conserved in amino acid sequences.
Though the identities of the nucleotide sequences of encoding region were 85.1–85.9% between MABV strains and IPNV serotype
A1 strains, they shared as high as 95.1–95.9% identities in amino acid level. A phylogenetic tree was constructed based on
the amino acid sequences of the RdRp gene from different birnaviruses including avibirnavirus and entomobirnavirus. Ten aquabirnavirus
strains were clustered into 3 Genogroups. The Genogroup I consisted of four IPNV A1 serotype strains. All MABV strains were
clustered into Genogroup II. Only IPNV SP strain was clustered into an independent Genogroup III.
Received August 19, 2002; accepted October 30, 2002 |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|