Nemirov Kirill, Henttonen Heikki, Vaheri Antti, Plyusnin Alexander
Department of Virology, Haartman Institute, University of Helsinki, PO Box 21, FIN-00014, Helsinki, Finland.
Virus Res. 2002 Dec;90(1-2):207-15. doi: 10.1016/s0168-1702(02)00179-x.
Phylogenetic analysis of three hantaviruses: Hantaan (HTNV), Dobrava (DOBV), and the newly designated serotype/genotype Saaremaa (SAAV) and their respective hosts, rodents of genus Apodemus, reveals a discrepancy in the virus-host relationships. While all Apodemus agrarius sequences from Europe and the Far East are monophyletic, SAAV (carried by the western subspecies of A. agrarius) shared the most recent ancestor with A. flavicollis-associated DOBV virus, but not with HTNV (carried by the eastern subspecies of A. agrarius). This suggests that host switching occurred in the evolution of these hantaviruses. A likely scenario includes transmission of ancestral DOBV to the western form of A. agrarius resulting in the ecological and reproductive isolation of ancestral SAAV. Approximate time-point of the hypothetical host switching estimated from maximum likelihood (ML) phylogenetic tree, 2.7-4.0 millions years ago (MYA), is closer to the present than the expected time of split between the two Apodemus species (not later than 6.5 MYA). Taken together with other proposed cases of host switching, our observations suggest that these events might not be exceptional in the hantavirus evolution.
对三种汉坦病毒（汉滩病毒（HTNV）、多布拉伐病毒（DOBV）以及新指定的血清型/基因型萨雷马病毒（SAAV））及其各自宿主（姬鼠属啮齿动物）进行的系统发育分析揭示了病毒与宿主关系中的差异。虽然来自欧洲和远东地区的所有黑线姬鼠序列都是单系的，但萨雷马病毒（由黑线姬鼠西部亚种携带）与黄颈姬鼠相关的多布拉伐病毒拥有最近的共同祖先，而与汉滩病毒（由黑线姬鼠东部亚种携带）并非如此。这表明在这些汉坦病毒的进化过程中发生了宿主转换。一种可能的情况是，祖先多布拉伐病毒传播到了黑线姬鼠的西部形态，导致了祖先萨雷马病毒的生态和生殖隔离。根据最大似然（ML）系统发育树估计的假设宿主转换的大致时间点为270万至400万年前（百万年前），比两种姬鼠物种之间预期的分裂时间（不晚于650万年前）更接近现在。结合其他提出的宿主转换案例，我们的观察结果表明，这些事件在汉坦病毒进化过程中可能并非罕见。
