蓝舌病毒野毒株及疫苗株S10基因多态性分析研究

对中国蓝舌病毒1株疫苗株、31株野毒株及1株南非毒株进行测序。结果揭示33株毒株S10基因核苷酸长度均为822bp，S10基因为基因内基因，其核苷酸链的第20～22和59～61位有两个起始密码子，共有终止子在707～709位，预测编码NS3和NS3A两种蛋白；32株中国毒株间核苷酸差异0～107个，同源性86%～100%; NS3蛋白氨基酸差异0～10个，同源性956%～100%。测序毒株与GenBank中9株其它毒株比较，建立的S10基因系统发生树，将蓝舌病毒分为China group和US group两大基因群，两大群的同源性为85%；US group包括美国8株及南非1株毒株；China group包括中国32株及澳大利亚1株毒株；说明蓝舌病毒S10基因分群与毒株的地理区域来源有关。在国内首次进行了全国较大范围内蓝舌病毒分子流行病学调查，揭示了我国蓝舌病毒毒株的遗传多样性。

Genetic Diversity Analysis of the S10 Gene of Field and Vaccine Strains of Bluetongue Virus

S10 gene sequences of 1 attenuated vaccine strain and 31 Chinese field isolates & 1 South Africa strain of BTV were determined. The results revealed that all 33 S10 gene segments have 822 nucleotides in length with two in-frame initiation codons (nucleotides 20 to 22 and 59 to 61) and a common termination codon (nucleotides 707 to 709), which encodes two proteins (NS3 and NS3A). Nucleotide difference in the sequence of all S10 gene were from zero to 107 bp (86.4% - 100% identity). NS3/NS3A protein showed a light difference from zero to 10 amino acid (95.6% - 100% identity). Phylogenetic analysis of the S10 gene of above strains sequenced and 9 other strains from GenBank, segregated the Chinese viruses into a monophyletic group distinct from US viruses; Nucleotide identity was 85% between China Group and US group. The various Chinese isolates segregated into two phyletic subgroups based on S10 gene sequences. The clustering of viruses was dependent of geographical origin, and independent of host species of isolation, serotype & year of isolation.