A型流感病毒中国分离株PB1-F2基因进化分析

Evolution Analysis of the PB1-F2 Genes of Influenza A Viruses Isolated from China

【目的】明确国内鸡源H9N2禽流感病毒(AIV)的PB1-F2基因分子进化特征,并进一步全面了解国内A型流感病毒(IAV)流行株的PB1-F2的流行情况。【方法】对分离自北方发病鸡群中的14株H9N2亚型AIV进行了PB1-F2基因的克隆和序列测定,并从GenBank数据库下载了禽源、猪源和人源H5N1和H9N2亚型AIV、人源和猪源H1N1和H3N2IAV的PB1基因共计337个,系统的对国内不同宿主来源的IAV的PB1-F2基因进行了分子进化分析。【结果】上述IAV的PB1-F2基因形成了6个不同的进化分支。推导的PB1-F2蛋白表现出长度的多态性,因IAV的HA类型和宿主来源的不同,其表达功能性PB1-F2蛋白的比率也存在差异。【结论】本研究明确了国内IAV的PB1-F2基因的系统进化特征,为该基因功能的研究提供了分子流行病学资料。

[ Objective ] The molecular characterization of PB1-F2 gene of chicken H9N2 subtype avian influenza viruses（AIVs） isolated from China was analyzed and the prevalence of the PBI-F2 genes of influenza A viruses （IAVs） prevailed in China was further investigated. [Method] Fourteen H9N2 viruses were isolated from sick chickens in China from 1998 to 2008. The sequences of the PB1-F2 genes of these isolates were determined by RT-PCR and sequencing. Then, 337 PB1 genes of IAVs derived from avian （H5N1, H9N2 subtype）, pig （H5N1, H9N2, H1N1 and H3N2.subtype） and human beings （H5N1, H9N2, H1N1 and H3N2 subtype） in China were downloaded from GenBank database and analyzed using molecular biological software. [Result] Phylogenic inference drawn from PB1-F2 sequences of the above IAVs showed six distinct clusters. The deduced sequences of PB1-F2 proteins have multifold lengths and the ratio of PB1-F2 genes encoding full-length PB1-F2 protein differed in the HA subtype and host origin of IAV isolates. [ Conclusion ] Through this study, the molecular epidemiologic characteristics of PB l-F2 gene of IAVs in China was illuminated, thus providing a basic foundation of PB1-F2 gene function research in the infection process of IAVs.