Abstract: 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.

Key words: canine distemper virus; h gene; cloning; prokaryocyte expression