Molecular and Cellular Biology Graduate Program, University of Washington, , Seattle, WA 98195, USA.
Philos Trans R Soc Lond B Biol Sci. 2013 Aug 12;368(1626):20120496. doi: 10.1098/rstb.2012.0496. Print 2013 Sep 19.
Simian immunodeficiency viruses (SIVs) have infected primate species long before human immunodeficiency virus has infected humans. Dozens of species-specific lentiviruses are found in African primate species, including two strains that have repeatedly jumped into human populations within the past century. Traditional phylogenetic approaches have grossly underestimated the age of these primate lentiviruses. Instead, here we review how selective pressures imposed by these viruses have fundamentally altered the evolutionary trajectory of hosts genes and, even in cases where there now remains no trace of the viruses themselves, these evolutionary signatures can reveal the types of viruses that were once present. Examination of selection by ancient viruses on the adaptive evolution of host genes has been used to derive minimum age estimates for modern primate lentiviruses. This type of data suggests that ancestors of modern SIV existed in simian primates more than 10 Ma. Moreover, examples of host resistance and viral adaptation have implications not only for estimating the age and host range of ancient primate lentiviruses, but also the pathogenic potential of their modern counterparts.
猿猴免疫缺陷病毒（SIV）在人类免疫缺陷病毒感染人类之前很久就感染了灵长类动物。在非洲灵长类动物中发现了数十种种特异性慢病毒，其中包括两种在过去一个世纪中多次跳跃到人类群体中的病毒株。传统的系统发育方法严重低估了这些灵长类慢病毒的年龄。相反，在这里我们回顾了这些病毒施加的选择压力如何从根本上改变了宿主基因的进化轨迹，即使在病毒本身现在没有留下任何痕迹的情况下，这些进化特征也可以揭示曾经存在过的病毒类型。通过研究古代病毒对宿主基因适应性进化的选择，已经可以对现代灵长类慢病毒的最小年龄进行估计。这种类型的数据表明，现代 SIV 的祖先存在于灵长类动物中超过 1000 万年。此外，宿主抗性和病毒适应性的例子不仅对估计古代灵长类慢病毒的年龄和宿主范围具有重要意义，而且对其现代对应物的致病潜力也具有重要意义。
