Cloning and Sequence Analysis of vp2 Gene of Porcine Parvovirus SD-68 Strain
Abstract: vp2 gene of Porcine parvovirus (PPV) SD-68 strain was cloned and sequenced .The results showed that vp2 gene of Porcine parvovirus (PPV) SD-68 strain was 1740bp and encoded a protein of 579 amino acids. vp2 gene of SD-68 strain exhibited over 99% nucleotide sequence identity and 96% amino acid sequence identity with other PPV strains: Kresse, SY-99, NADL-2(5075), NADL-2(4973), US-1. Phylogenetic tree analysis of vp2 gene showed the closest relationship between SD-68 strain and kresse strain. The difference between SD-68 strain and kresse strain was only on 378, 383 and 436 residues, which decided the tissue tropism of PPV, so the tissue tropism of SD-68 strain suggested more similar with kresse stain, that is to say, SD-68 was a dermatitis strain. Comparison of amino acid residues of virulent strain (kreese) and vaccine strain (NADL-2 and SD-68) suggested that 215, 378 and 383 were important residues that decided the pathogenicity of PPV.