IBDV不同野毒株鸡胚传代过程中VP2基因变异动态的研究

Study on the Variation of VP2 Genes of IBDV Field Isolates Adapted in Chicken Embryo

对分离于河南省的YX08、YX12和YB02 3个IBDV野毒株进行了鸡胚连续传代,对各变异代数的VP2高变区基因进行了RT-PCR扩增和序列分析。结果显示,各毒株随传代次数的增加,与经典毒株Cu-1及弱毒株P2的同源性有所增高;各毒株的变异代数和变异位点不尽相同,232位、233位、234位及253位氨基酸的密码子在传代过程中是易变密码子。

The IBDV field isolates,YX08,YX12 and YB02 were successfully cultivated in chicken embryos. The VP2 genes of each variable generation were amplified by RT-PCR and sequenced. Analysis of every generation viruses showed that compared to the Cu-1 classical IBDV and P2 attenuated IBDV, the homology of nucleutide and amino acid were increased along with the passages in chicken embryo. The variable generation of VP2 gene and its variable position were different. But the codons of amino acids on the sites of 232,233,234 and 253 were hypervariable positions.