Isolation Of PRRSV And Analisis Of It's ORF5 Gene

The Porcine Reproductive and Respiratory Syndrome(PRRS) is a new infectious disease caused by porcine reproductive and respiratory syndrome virus(PRRSV). Since the disease broke out first in America in 1987,great damages have took place in pig industry.This research use Porcine Alveolar Macrophages (PAMs) to isolate virus from tissue of pigs that diagnosis is the PRRSV infection and 15 virus are isolated from them. According to the ORF5 gene sequence (contained the partial ORF4 and partial ORF6 gene) of American type PRRSV VR 2332 in GeneBank to design and synthesizes primers, about 760bp cDNA sequence of 15 isolates were amplified by RT-PCR and sequenced after being directly cloned into the pMD-18T.The sequences of ORF5 genes of 15 isolates were compared with the sequences of other domestic and foreign PRRSV strains has published in Genbank by the DNAStar software , and applying the DNAStar software to compare characteristics of 15 isolates GP5 prorein with other strains, the results indicated 15 isolates relationship are near with American type PRRSV, deduct amino acid sequence homology is 88.9%-99.8%. And the15 isolates belong to one branch , from which we can conjecture they root in the same one.