Cloning and Prokaryocyte Expression of Hemagglutinin Protein Gene of Canine Distemper Virus

A pair of primers was designed based on the h gene sequence of canine distemper virus in GeneBank,the h gene of(CDV) strain isolated from an attenuated vaccine strain of canine distemper virus was amplified by reverse transcription polymerase chain reaction(RT-PCR).The amplified fragment was cloned into pMD18-T simple vector and the positive recombinants were identified by blue-white screening and restriction endonuclease digestion,and the h fragments were sequenced and analyzed.Sequencing analysis indicates that the gene was the same to the representive canine distemper virus h gene.h gene was 90.6%,91.3%,90.5%,91% identical to Yangzhou isolates,Changchun isolate,XinJiang isolate and Japanese isolateD85755 respectively.It was 97.7%,97.2%,98.1% indentical to Onderstepoort strain,Convac strain and American isolates 98-2666-2 respectively.Then the h gene was subcloned into Prokaryotic expression plasmid pET-32a(+).Recombinantplasmid carrying h gene(pET-32a-h) was transformed into E.coli BL21(DE3) and induced with IPTG.A fusion protein about 64 ku was expressed.