Phylogenetic characterization of genes encoding for glycoprotein 5 and membrane protein of PRRSV isolate HH08

Abstract

A porcine reproductive and respiratory syndrome virus (PRRSV) was obtained from clinic samples. Genes 5 and 6 encoding for the viral glycoprotein 5 and a membrane protein of the PRRSV designated as HH08 were amplified by reverse transcription-PCR. These sequences were compared with reference sequences derived from different geographical locations. The results indicated that the virus belongs to the North American type rather than European. Comparative analyses of the genetic diversity between the PRRSV isolate HH08 and other Chinese as well as foreign reference strains of PRRSV were discussed based on the sequence comparison and the topology of phylogenetic trees constructed in this study.

Fig. 1

Phylogenetic tree construction. Based on the open reading frame (ORF)5 and ORF6 gene sequences, the corresponding phylogenetic trees for ORF5 (A) and ORF6 (B) genes were constructed. The isolate name, isolating year, origin place as well as GenBank accession number are indicated. The virus isolated in this study and the vaccine strains are framed. The bootstrap value is 10,000.

Fig. 2

Multiple sequence alignment of the ORF5 gene. The ORF5 gene of porcine reproductive and respiratory syndrome virus (PRRSV) isolate HH08 was compared with representative ORF5 genes of different PRRSV subgroups based on the phylogenetic tree analysis. The framed parts are point mutations in the GP5 gene between HH08 and CH-1a, and a total of three amino acid mutations are identified. There is a silence mutation in nucleotide position 148.