中文摘要：

本研究对1998年～2012年分离自我国的32株H9N2亚型禽流感病毒的NS基因进行了克隆和序列测定,并对这些序列进行了系统分析。进化分析表明,在我国流行的H9N2亚型禽流感病毒的NS基因主要属于等位基因A群的BJ/94分支,而属于G1分支的毒株很少被分离到;我国H9N2流行株不断演化出新的亚分支,2000年之前的毒株主要属于Y280亚分支,2007年之后F/98亚分支的毒株逐渐演化为优势谱系。对毒株氨基酸序列的分析表明,部分H9N2亚型禽流感病毒的NS蛋白具有高致病性毒株的分子特征。

英文摘要：

Thirty-two nonstructural （NS） genes Of H9N2 subtype avian influenza viruses （AIV）, iso- lated from chicken in China during 1998-2012, were Completely sequenced and phylogenetically analyzed in the research. The results showed that NS genes mainly belonged to BJ/94-1ike lineage Of allele A, and which belonged to Gl-like lineage were rarely isolated. HgN2 subtype epidemic strains constantly evolved into new sub-branches. The NS gene of HgN2 strains before 2000 mainly belonged to Y280-1ike sub-clade, while after 2007 F/98 sub-clade gradually evolved into the dominant lineages. Amino acid sequences analy- sis showed that the NS genes of some HgN2 viruses owned the characteristic animo acids related to high pathogenictity.