【摘要】 对 2 0 0 1年中国华南及东北地区的 15株H1N1亚型猪流感病毒 (SIV)分离株的血凝素 (HA)基因进行了序列测定和分析 ,并绘制了进化树。研究结果表明 ,15株H1N1SIV和HA基因核苷酸全长为 1778bp ,共编码 5 6 6个氨基酸 ;而且 ,15株H1N1亚型SIV的HAI蛋白在 10、11、2 3、87、2 87位都存在高度保守的糖基化位点 ,此外 ,在 2 76位多了一个“_NTT_”糖基化位点 ,与参考毒株SW /IW / 93/ 0 1一致 ,这可能是近期H1N1亚型SIV的一个分子特征。本研究进一步发现 ,15株H1N1亚型SIV的HA基因切割位点氨基酸组成为IPSIQSR↓G ,具有非高致病力毒株分子特征 ;而其受体结合位点在HA蛋白上第 2 2 6位是Q ,第 2 2 8位是G ,可能具有感染禽的潜力。经同源性比较 ,15株H1N1亚型SIV的HA基因与古典型H1N1猪谱系中的WIS/ 4 75 4 / 94的同源性相对最高 ,核苷酸和氨基酸序列同源性分别达到 95 7%～ 96 1%和96 5 %～ 97 2 %。由同源性比较结果和进化树分析可见 ,15株H1N1亚型SIV的HA基因皆属于古典型H1N1猪谱系更多还原

【Abstract】 The hemagglutin (HA) genes of fifteen H1N1 subtype Swine Influenza Viruses (SIVs)which isolated from swine in south and northeast of China in 2001, were sequenced and molecular evolutionarily analyzed in this study.The results suggested that the whole length of HA genes of all 15 isolates were composed of 1?778?bp,coding 566 amino acids.Their amino acids in highly conservative at the 10,11,23,87 and 287 sites in glycosylation sites of HA1;However,there is "-NTT-" at the 267 site,which may be one molecular characteristics of H1N1 subtype SIV recently.The data on HA sequences revealed inferred from the characteristics of the viral HA gene that those isolates did not belong to the high pathogenic viral strains;Moreover,the Key amino acid was Q and G at the 226 and 228 sites in HA receptor-binding sites, which means all 15 isolates bind SAa-2,3-Gal,prior to SAa-2,6-Gal.Compared with the strains from GenBank,their homologies of nucleotide and amino acid sequences with A/Wisconsin/23/1994 (H1N1) were 95.7?%～96.1?% and (96.5?%)～97.2?%, respectively.The phylogenetic tree and homology revealed that the HA genes of the fifteen strains SIVs isolated from the mainland of China belonged to the classical swine H1 influenza virus lineage.更多还原