Cloning And Sequences Analysis Of Structural Protein Genes Of PRRSV-XJPRRSV1/03

In this study,the total RNA of cells-PRRSV was extracted,according to VR2332 and CH-la strain,designed six pairers GP2-1/GP2-2,GP3-1/GP3-2,GP4-1/GP4-2,GP5-1/GP5-2,M1/M,N1/N2, structural protein genes fragments of porcine reproductive and respiratory syndrome virus(PRRSV) XJPRRSV1/03 strain were amplified by RT-PCR,cloned into pMD-18T vector and pGM-T vector and sequenced.Processed the sequences by DNAstar software,obtained the length of structural gene sequence is 771,765,537,603,524 and 372 nucleotides(nts),encoding256,254,178,200,174and 123 amino acids, respectively.Comparision of the homology among VR-2332,RespPRRS RESPPRRS MLV,BJ-4,Lelystad virus(LV)and other 17 strains of PRRSV,the results shown that the homology of nucleotide sequences and deduced amino acid sequences of GP2 gene among XJPRRSV1/03 and Nother American strains was 92.7-99.7%and 91.1-100%,respectively.And it was higher than the homology between XJPRRSV1/03 and typical European strain LV,which was only 62.5%and 63.7%,resepectively.The homology of nucleotide sequences and deduced amino acid sequences of GP3 gene among XJPRRSV1/03 and North American strains was90.3-95.7%and 87.5-95.3%,respectively.It was higher than the homology between XJPRRSV1/03 and LV,which was only 73.4%and 75%,respectively.The homology of nucleotide sequences and deduced amino acid sequences of GP4 gene among XJPRRSV1/03 and North American strains was 90.0-99.8%and 88.9-100%,respectively.It was higher than the homology between XJPRRSV1/03 and LV,which was only 67.8%,respectively.The homology of nucleotide sequences and deduced amino acid sequences of GP5 gene among XJPRRSV1/03 and North American strains was89.7-95%and 88.3-97.5%,respectively.It was higher than the homology between XJPRRSV1/03 and LV,which was only 64.2%and 58.9%,respectively.The homology of nucleotide sequences and deduced amino acid sequences of M gene among XJPRRSV1/03 and North American strains was 94.3-99.8% and 97.2-100%,respectively.It was higher than the homology between XJPRRSV1/03 and LV,which was only 68.6%and 78.9%,respectively.The homology of nucleotide sequences and duduced amino acid sequences of M gene XJPRRSV1/03 and North American strains was 93.3-97.3%and 93.6-99.2%,respectively.It was higher than the homology between XJPRRSV1/03 and LV,which was only 67.4%adn 64.8%,respectively.Furthermore,it was found that the homology was very high among XJPRRSV1/03 and VR-2332,ResPPRRS MLV,CC-1 and BJ-4 strains,but the homology was very low among XJPRRSV1/03 and LV.And the phylogenetic trees revealed that XJPRRSV1/03 strain perhaps has a close relationg to S1,VR-2332,ResPPRRS MLV,CC-1 and BJ-4 strains.These results suggested that XJPRRSV1/03 strain belongs to North American type.