Cloning and expression of the vp7 gene antigenic region of porcine rotavirus OSU virulent strain

The vp7 gene of porcine rotavirus (PRV) OSU strain was amplified by RT-PCR using a pair of specific primers designed according to the published sequence in GenBank. The PCR products were cloned to pMD18-T vector and sequenced. The vp7 of OSU strain consisted of 1 062 bp and shared 99.8 % sequence homology with PRV vp7 gene from NCBI. A 639 bp fragment containing the neutron-antigenic epitope was amplified from the vp7 gene and subcloned into expression vector pGEX-6P-1. The construct was transformed E.coli BL21 (DE3) and induced by IPTG. The expressed GST-fusion protein had a molecular weight of 50 ku that accounted for up to 33.2 % of total protein. Western blot showed that the recombinant VP7 protein reacted with polyclonal antibodies against PRV.