Isolation and Sequence Analysis of NSP2, ORF3 and ORF5 of PRRSV XH-GD Strain from Guangdong Provlace

摘要

The diseased samples collected from Guangdong Province were inoculated to Marc-145 cells,PRRSV-specific cytopathogenic effects( CPE) such as cell aggregation,cell shrinkage and cell exfoliation were observed and a PRRSV strain XH-GD was obtained. By using primers designed in accordance with the published gene sequences of PRRSV in GenBank,NSP2,ORF3 and ORF5 fragments were amplified by reverse transcription polymerase chain reaction and analyzed by sequence alignment. The results demonstrated that PRRSV strain XH-GD belonged to the North American genotype and the NSP2 gene contained discontinuous deletions of 30 amino acids. NSP2,ORF3 and ORF5 genes of XH-GD shared 83. 3%- 98. 9%,88. 6%- 99. 2% and 88. 1%- 99. 2% nucleotide homology,and76. 8%- 98. 3%,83. 7%- 98. 8% and 88. 1%- 99. 2% amino acid homology with HUB1,NX06,BJsy06,VR-2332,HB-1( sh) 2002,HB-2( sh) 2002,CH-la and RespPRRS MLV,respectively; however,NSP2,ORF3 and ORF5 genes of XH-GD shared only 52. 9%,65. 0% and 64. 3% nucleotide homology,and31. 3%,57. 5% and 58. 9% amino acid homology with LV,respectively. Phylogenetic analysis revealed that XH-GD had a closer relationship with HUB1,NX06,BJsy06,VR-2332,HB-1( sh) 2002,HB-2( sh) 2002,CH-la and RespPRRS MLV strains compared with LV strain.