Sequence Analysis And Construction Of Eukaryotic Expression Vectors Of H And N Gene Of CDV Isolated From Fox And Raccoon Dog

Canine distemper(CD) is one of the most severe infectious disease in fur animalpopulations, it can cause 60%-100% death rate and even destroy the fur animal farming;especially the vaccinated animals can be still infected seriously by CDV recently, the fact is anew challenge for the prevention of CDV.48 suspicious case samples of foxes and raccoon dogs were collected from defferent areasof Heilongjiang province from 2004 to 2006, these vaccinated animals were detected bypathology characteristics and RT-PCR, about 85% animals were infected by CDV, this showedthat CD endangered the breeding of fur animals all the same.Two fragments of H and N gene were amplified by RT-PCR from three CDVstrains(MS01, SC01, ZD01) which were isolated from fox and raccoon dog. The PCRproducts were cloned and then sequenced. The result indicated that the ORF of H gene of threestrains are all 1824bp and encode 607 acids and the ORF of N gene of three strains are all1572bp and encode 523 acids. The homology between the three strains and other strains inGenBank database was analyzed and a phylogenetic tree was built by DNAstar. The resultshowed that the three strains had higher homology with wild-type strains, while they had lowerhomology with vaccine strains. The analysis of phylogenetic tree of H and N gene showed acertain extent geographical relativity, the result was possible to explain why CD was prevalentin vaccinated animals.The H and N gene of CDV MS01 isolate were cloned into the eukaryotic expressionvector pcDNA3.1(+), the two recombined plasmids pcDNA-H and pcDNA-N were identifiedby PCR and digestion with restriction enzymes. The experiments are the fundamental study ofmore researches of DNA vaccine for fur animals.