Laboratory of Molecular Microbiology, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia.
Infect Genet Evol. 2012 Dec;12(8):1597-604. doi: 10.1016/j.meegid.2012.07.011. Epub 2012 Aug 2.
The data on the structure of conserved genes of the Old and New World orthopoxviruses and unclassified Yoka poxvirus were used for a Bayesian dating of their independent evolution. This reconstruction estimates the time when an orthopoxvirus ancestor was transferred to the North American continent as approximately 50 thousand years ago (TYA) and allows for relation of this time interval with the global climate changes (with one of the short-term warmings during the Last Ice Age). The onset of the Yoka poxvirus evolution was assessed as approximately 90TYA. Availability of a large number of genome sequences of various cowpox virus strains provided for a comprehensive analysis of the orthopoxvirus evolutionary history. Such a study is especially topical in view of the postulated role of this virus in the evolution of various orthopoxviruses, namely, as an progenitor virus. The computations have demonstrated that the orthopoxviruses diverged from the ancestor virus to form the extant species about 10TYA, while the forbear of horsepox virus separated about 3TYA. An independent evolution of taterapox, camelpox, and variola viruses commenced approximately 3.5TYA. Study of the geographic distribution areas of the hosts of these three orthopoxviruses suggests the hypothesis on the region of their origin. It is likely that these viruses first emerged in Africa, in the region of the Horn of Africa, and that the introduction of camels to East Africa induced their divergent evolution.
利用旧大陆和新大陆正痘病毒以及未分类的约卡痘病毒的保守基因结构数据，对它们的独立进化进行了贝叶斯时间估计。这种重建估计了正痘病毒祖先转移到北美大陆的时间大约是 5 万年前（TYA），并允许将这段时间间隔与全球气候变化（在上一个冰河时代的一次短期变暖期间）联系起来。约卡痘病毒进化的开始时间估计约为 90TYA。大量各种牛痘病毒株的基因组序列的可用性，为正痘病毒的进化史提供了全面的分析。鉴于该病毒在各种正痘病毒的进化中被假定的作用，即作为原病毒，这种研究尤其具有现实意义。计算表明，正痘病毒从祖先病毒分化为现存物种大约发生在 10TYA 前，而马痘病毒的祖先大约在 3TYA 前分离。牛痘病毒、骆驼痘病毒和天花病毒的独立进化大约发生在 3.5TYA 前。对这三种正痘病毒宿主的地理分布区的研究提出了它们起源的区域假说。这些病毒很可能首先在非洲的非洲之角地区出现，而将骆驼引入东非则导致了它们的分化进化。
