Luo C, Morishita T, Satou K, Tateno Y, Nakajima K, Nobusawa E
Department of Virology, Nagoya City University Medical School, Nagoya, Japan.
Arch Virol. 1999;144(10):1881-91. doi: 10.1007/s007050050712.
Phylogenetic analysis was carried out for genes encoding hemagglutinin (HA) (24 new and 25 previously reported sequences) and nonstructural proteins (NS) (22 new and 14 previously reported sequences) of influenza B virus isolates obtained from 1940 to 1999. Two antigenically and genetically distinct HA lineages are presently known to exist. Divergence into these two lineages was estimated to have occurred around 1969. Phylogenetic analysis of NS genes revealed that their phylogenetic relationships were not linked to the two HA lineages but suggested that reassortment of viral genes between the viruses of two HA lineages had occurred. In addition two distinct NS lineages which were not linked to the two HA lineages were observed. Viruses isolated after 1997 formed their own lineage in combination with B/Houston/84 while other virus isolates obtained from 1973 to 1995 comprised the other NS lineage.
对1940年至1999年间分离出的乙型流感病毒株的血凝素（HA）编码基因（24个新序列和25个先前报道的序列）和非结构蛋白（NS）编码基因（22个新序列和14个先前报道的序列）进行了系统发育分析。目前已知存在两个抗原性和基因上不同的HA谱系。据估计，这两个谱系的分化发生在1969年左右。NS基因的系统发育分析表明，它们的系统发育关系与两个HA谱系无关，但提示两个HA谱系的病毒之间发生了病毒基因重配。此外，还观察到两个与两个HA谱系无关的不同NS谱系。1997年后分离出的病毒与B/休斯顿/84组合形成了它们自己的谱系，而1973年至1995年获得的其他病毒分离株则构成了另一个NS谱系。
