华东地区家鸭中N2亚型低致病性禽流感病毒神经氨酸酶基因的重排

Neuraminidase gene reassortment of low pathogenic avian influenza viruse N2 subtype among domestic ducks in Eastern China

为研究华东地区家鸭中低致病性禽流感病毒NA基因的遗传进化规律,对2000年-2006年分离的包括H3N2,H5N2,H6N2,H9N2和H11N2的44株禽流感病毒的NA基因进行了遗传进化分析。44株病毒NA基因之间的同源性为82.9%-99.9%,4株H9N2病毒的NA基因同源性为96.9%-99.9%,所有H3N2病毒的NA基因同源性为92.3%-99.9%,H5N2、H6N2和H11N2病毒的同种亚型毒株间的NA基因同源性变化幅度较大,相反,有些不同HA亚型毒株间的NA基因同源性反而很高。进一步分析NA基因推导的氨基酸序列也表现出相似的规律。华东地区家鸭中N2亚型的禽流感病毒正处于不断地进化状态中,不同N2亚型的禽流感病毒之间已存在NA基因的重排。

In order to identify the phylogenetic features of neuraminidase（NA） genes of low pathogenic avian influenza viruses among domestic ducks in Eastern China,the NA genes of 44 viruses isolated during 2000-2006 and including H3N2,H5N2,H6N2,H9N2 and H11N2,were subjected to analysis.The nucleotide sequences of 44 NA genes demonstrated a similarity of 82.9%-99.9%.The homology of 4 H9N2 viruses was 96.9%-99.9%,and that of all H3N2 viruses was 92.3%-99.9%.However,the homology of NA genes of H5N2,H6N2 and H11N2 was dramatically diverse.On the contrary,some NA genes from viruses of different HA subtypes shared a high degree similarity.Further analysis of the deduced amino acid sequences of NA genes showed the similar results.Avian influenza viruses of N2 subtype circulating in domestic ducks in Eastern China were experiencing a gradual evolution.The genetic reassortment in NA genes of different N2 subtype AIVs had occurred.