National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2012

03. Genetic diversity of non-structural proteins 2 and 5 in porcine rotavirus B

Japanese

Porcine rotavirus B (RVB) is a pathogen that causes severe diarrhoea in suckling and weaned pigs. Because RVB is difficult to propagate in serial cell cultures, genetic information known about its RNA segments remains limited. Non-structural proteins 2 and 5 (NSP2 and NSP5) are thought to be closely involved in viral replication. In the present study, we conducted sequence and phylogenetic analyses of the NSP2 and NSP5 genes by using several porcine RVB strains collected throughout Japan. Sequence analysis showed that each NSP2 and NSP5 gene from the viral strains studied contained one ORF. Alignment of NSP2 amino acid sequences from porcine and other RVB strains indicated that the conserved histidine triad motif was present in all RVBs. Comparison of NSP5 amino acid sequences from porcine RVBs and other RVBs revealed that eight serine and serine/threonine residues were highly conserved among the RVBs. Comparison of NSP2 and NSP5 nucleotide sequences and deduced amino acid sequences from porcine RVB strains exhibited little similarity with those of human and bovine RVB strains, suggesting high genetic divergence of porcine RVB. Moreover, phylogenetic analysis classified RVB NSP2 and NSP5 into 4 and 6 genotypes, respectively, according to genetic relatedness and species of origin. Notably, the NSP2 and NSP5 genes of the porcine RVB strains were divided into 3 genotypes. Our findings contribute to the elucidation of the evolution and ecology of RVB.
(Viral Disease and Epidemiology Research Division)

References:

  • Suzuki T. et al. (2012) Virus Res. 165:46-51
  • Suzuki T. et al. (2012) Infect. Genet. Evol. 12:1661-1668

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