The Advance in Molecular Biology of Porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory sydrome (PRRS)is presently one of the most important viral infectious disease of swine, which is characterized by severe reproductive failure and respiratory distress. The viral etiology of PRRSV is PRRSV, which belongs to the Arteriviridae family and has a nonsegmented, single-stranded and positive-sense RNA genome. PRRSV consists of eight overlapping opening reading frames(ORFs)and ORF1 encodes the non-structual protein and the ORF2-ORF7 codes the structural proteins. Especially the nucleocapsid(N)protein encoded by ORF7 and the nonglycosylated membrane(M) protein encoded by ORF6 are the major structural proteins. The viral genetic variation exists widely and the M protein and the N protein are comparatively steady in all strains,which can be used as antigens for serological diagnosis.The article discussed some aspects about PRRSV researches on molecular biology.