Genetic characteristics and restriction fragment length polymorphism analyses of the hemagglutinin gene of canine distemper virus isolates in Wuhan Prefecture of China.

According to the canine distemper virus sequence available in the NCBI,a pair of primers was designed for the testing of mouth,nose and anus swabs of clinic pet dogs in Wuhan.Six of those positive samples were randomly taken for amplifying and sequencing of the hemagglutinin gene.Sequence analysis showed that viruses were divided into two clusters of wild-type and vaccine virus,respectively,and the wild virus had close relationship with its geographic location.Analysis result of predicted protein sequence showed that the potential N-linked glycosylation sites between vaccine and separation strains were very different,which may be one of reasons for the viral antigen changes.Then an assay of restriction fragment length polymorphism was developed according to the result of sequence analysis.Based on that a method for differential diagnosis between vaccine and wild-type viruses was established.