Cloning and Optimizing Expression of E_2 Gene of Bovine Viral Diarrhea-mucosal Disease Virus in BCG

To develop genetic engineering living-vector vaccine of Bovine viral diarrhea-mucosal disease virus(BVDV),E_2 gene of BVDV Changchunl84 strain was selected and the complete sequence was analyzed,then the epitopes of E_2 protein were predicted by bioinformatics software.Six pairs of primers were designed according to E_2 gene sequence,and the epitopes coding regions(1-297,1-345,1-374,45-297,45-345,45-374) of E_2 gene were amplified by PCR and cloned into pMV361 vector.PCR,restriction endonuclease digestion and sequence analysis proved that the 6fragments were inserted into the expected position.It was indicated that the six prokaryotic expression plasmids were constructed.The positive recombinant plasmids were electro-transformed into BCG for expression at 45℃.The SDS-PAGE and Western blot results indicated that the recombinant proteins could react with polyclonal antibody against BVDV.Our study provides a basis for the further studies on genetic engineering living-vector vaccine of BVDV.