Hiromoto Y, Yamazaki Y, Fukushima T, Saito T, Lindstrom S E, Omoe K, Nerome R, Lim W, Sugita S, Nerome K
Department of Virology I, National Institute of Infectious Diseases, 23-1, Toyama 1-chome, Shinjuku-ku, Tokyo 162-8640, Japan.
J Gen Virol. 2000 May;81(Pt 5):1293-303. doi: 10.1099/0022-1317-81-5-1293.
The entire nucleotide sequences of all six internal genes of six human H5N1 influenza A viruses isolated in Hong Kong in 1997 were analysed in detail from a phylogenetic point of view and compared with the evolutionary patterns of the haemagglutinin and neuraminidase genes. Despite being isolated within a single year in the same geographical location, human H5N1 viruses were characterized by a variety of amino acid substitutions in the ribonucleoprotein complex [PB2, PB1, PA and nucleoprotein (NP)] as well as the matrix (M) proteins 1 and 2 and nonstructural (NS) proteins 1 and 2. The presence of previously reported amino acid sequences specific for human strains was confirmed in the PB2, PA, NP and M2 proteins. Nucleotide and amino acid sequence identities of the six internal genes of H5N1 viruses examined here were separated into at least two variant groups. In agreement with the above result, phylogenetic trees of the six internal genes of human H5N1 viruses were generally composed of two minor clades. Additionally, variable dendrogram topologies suggested that reassortment among viruses contributed further to the genetic variability of these viruses. As a result, it became clear that human H5N1 viruses are characterized by divergent gene constellations, suggesting the possible occurrence of genetic reassortment between viruses of the two evolutionary lineages.
从系统发育的角度详细分析了1997年在香港分离出的6株人类H5N1甲型流感病毒的全部6个内部基因的核苷酸序列，并与血凝素和神经氨酸酶基因的进化模式进行了比较。尽管人类H5N1病毒是在同一年于同一地理位置分离得到的，但它们的核糖核蛋白复合体[PB2、PB1、PA和核蛋白(NP)]以及基质(M)蛋白1和2和非结构(NS)蛋白1和2中存在多种氨基酸替换。在PB2、PA、NP和M2蛋白中证实了先前报道的人类毒株特异性氨基酸序列的存在。此处检测的H5N1病毒的6个内部基因的核苷酸和氨基酸序列同一性至少分为两个变异组。与上述结果一致，人类H5N1病毒6个内部基因的系统发育树通常由两个小分支组成。此外，可变的树状图拓扑结构表明病毒之间的重配进一步增加了这些病毒的遗传变异性。结果表明，人类H5N1病毒具有不同的基因组合特征，这表明两个进化谱系的病毒之间可能发生了基因重配。
