H5N1亚型禽流感病毒HA基因核酸序列的变异分析

从GenBank上获得194株不同来源的H5N1亚型禽流感病毒HA基因核酸序列，利用MEGA3分析了HA基N核酸序列碱基突变的特点。并通过比较序列同源性，构建NJ系统进化树，探讨了不同来源的H5N1病毒的系统进化关系。序列分析结果表明，被研究的194条H5N1亚型禽流感病毒HA基因核酸序列，碱基长度大约在1700bp左右，共发现了757个可变位点，其中Parsimony—informative sites有537个，Singleton sites有220个；病毒的变异速率很快，平均变异率为3．23％；病毒的序列变异具有显著的地区特点和时间特点；同时，全球化的贸易以及候鸟的迁徙在传播病毒过程中起一定作用。

Analysis on mutation in HA gene nucleotide sequences of H5N1 influenza virus

We downloaded 194 nueleotide sequences of HA gene of H5N1 influenza vires from C, enBank, and studied the mutation of these sequences using the software - MEGA3. Comparing these sequences, we structured the N - J phylogenetie tree, and disoussed the evolutional relatiouship of H5N1 influenza viruses from different areas, periods and hosts, The sequences analysis suggests that in about 1700bp sequence of HA gene, there are 757 mutation sites. Of them, 537 are parsimony - informative sites and 220 singleton sites. The virus mutates rapidly with average mutation ratio of 3.23%. The result also shows that there are some obvious traits depending on different areas and different periods, and the worldwide trade and migration of migrants have an impact on the prevalence of avian influenza.