华南流感病毒NS1基因特性研究

Characterization of NS1 Gene of Influenza A Virus in Southern China

为了解H9N2和H5N1亚型流行性感冒病毒株的NS1基因特性 ,采用RT PCR方法测定了 12株 2 0 0 0～2 0 0 3年间在华南地区分离的禽流感病毒株的NS1基因核苷酸序列 .测序显示 6株H9N2亚型流感病毒NS1基因开放阅读框 (ORF)长 6 5 4bp ,编码 2 17个氨基酸 .6株H5N1亚型毒株NS1基因ORF长 6 78bp ,编码 2 2 5个氨基酸 .核苷酸和氨基酸同源性分析表明 ,同一亚型分离株之间有很高的同源性 ,而不同亚型的H9N2和H5N1毒株之间存在较大差异 .BLAST分析表明 ,H5N1和H9N2亚型流感病毒分离株的NS1基因分别与近两年从香港特区和华南地区的鸭中分离的毒株A/Duck/HongKong/ 6 4 6 3/ 0 1(H5N1)、A/Duck/Shantou/ 2 14 3/ 0 1(H9N2 )有很高的亲缘关系 .该研究结果为进一步进行NS1功能研究奠定了基础 .

In order to understand the characterization and genetic mutations of the NS1 gene of the H9N2 and H5N1 subtype avian influenza viruses(AIV),the nucleotide sequences of NS1 regions of 12 strains of AIV from 2000～2003 in southern China were tested. The NS1 genes were amplified by RT-PCR and inserted into the pMD 18-T vector, then the recombinant plasmids were transformed into competent DH5α. The sequence analysis demonstrated that the NS1 genes of H9N2 subtype contained 654 bp and encoded 217 amino acids, and the NS1 genes of H5N1 subtype contained 678 bp and encoded 225 amino acids. The homologies of amino acid sequences of NS1 protein between H9N2 were 97.7%～94.9%, and the homologies of amino acid sequences of NS1 protein between H5N1 were 99.1%～97.8%. The H9N2 and H5N1 subtype isolates were closer to some AIV strains prevalent in southern China and Hong Kong in recent years. The results require further studying the role of the NS1 protein in the evasion of the host innate defense and potential contribution to pandemic influenza.