鸭肝炎病毒GD-B株生物学特性测定及多聚蛋白基因序列分析

Biological Characteristics and Sequence Analysis of Polyprotein Gene of Duck Hepatitis Virus GD-B Strain

根据Ⅰ型鸭肝炎病毒(DHV-Ⅰ)基因组序列设计并合成引物,通过RT-PCR方法分段扩增鸭肝炎病毒GD-B株多聚蛋白基因并克隆测序,构建多聚蛋白核苷酸系统进化树,并测定GD-B株部分生物学特性。结果表明,GD-B株多聚蛋白基因核苷酸序列与DHV-Ⅰ型GFS99广东株同源性最高(99.5%),属Ⅰ型鸭肝炎病毒,其EID50为10-4.62/0.2mL,LD50为10-4.13/0.3mL,与标准DHV-Ⅰ中和指数为23,提示GD-B株发生了抗原变异。

The polyprotein gene sequences of duck hepatitis virus type1（DHV-I）GD-B strain were amplified by RT-PCR with the primers designed according to the conserved region of DHV-1 genome.The sequences of polyprotein gene were analyzed by DNAStar software and the phylogenetic trees were constructed.The results showed that the GD-B strain had closest relationship with DHV I GFS99 strain sharing 99.5% identity.The CEID50and LD50of GD-B strain were 10-4.68/0.2 mL and 10-4.13/0.3 mL respectively.The lower immune protection for GD-B strain with DHV-Ⅰstandard positive serum in neutralization test indicated that the antigenic variation could occur in GD-B strain.