An Asian origin for subtype IVBK virus based on phylogenetic analysis
An Asian origin for subtype IVBK virus based on phylogenetic analysis
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DOI：
10.1007/s00239-006-0269-6
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发表时间：
2007-07-01
影响因子：
3.9
通讯作者：
Yogo, Yoshiaki
中科院分区：
文献类型：
--
作者：
Nishimoto, Yuriko;Zheng, Huai-Ying;Yogo, Yoshiaki
与多瘤病毒科的其他成员类似，BK病毒（BKV）被认为是与其人类宿主共同进化的。BKV有四种亚型，可通过免疫反应性加以区分，其中两种（亚型I和亚型IV）在人群中最为流行。亚型I是世界范围内的主要亚型，而亚型IV在东亚和欧洲普遍存在，但在非洲很少见。第四亚型BKV的地理分布格局显然与BKV与人类共同进化的假设不一致，因为第四亚型很少发生在非洲。为了阐明IV亚型的起源，利用最大似然和邻居连接方法对来自东亚和欧洲的53个完整的IV亚型序列进行了详细的系统发育分析。我们确定了六个子组（a1, a2, b1, b2， c1和c2），它们形成了一个由公式表示的树：“（a1, a2）， (（b1, b2), (c1, c2)）”。有趣的是，我们发现IV亚型亚群与人口地理密切相关；因此，除c2外，所有亚群都在东亚人群中普遍存在，c2在欧洲和东北亚均有发生。根据这些发现，我们得出结论，现在流行于现代人类的BKV亚型IV源自一种感染亚洲祖先的病毒。我们提出了两种假设来解释祖先亚洲人是如何感染亚型BKV的。
Similarly to other members of the Polyomaviridae family, BK virus (BKV) is thought to have co-evolved with its human host. BKV has four subtypes that are distinguishable by immunological reactivity, with two (subtypes I and IV) being most prevalent in human populations. Subtype I is the major subtype worldwide, whereas subtype IV is prevalent in East Asia and Europe but rare in Africa. The geographic distribution pattern of subtype IV BKV is in apparent disagreement with the hypothesis that BKV co-evolved with humans, since subtype IV rarely occurs in Africa. To elucidate the origin of subtype IV, 53 complete subtype IV sequences derived from East Asians and Europeans were subjected to a detailed phylogenetic analysis using the maximum-likelihood and neighbor-joining methods. We identified six subgroups (a1, a2, b1, b2, c1, and c2) that formed a tree represented by the formula: "(a1, a2), ((b1, b2), (c1, c2))." Interestingly, we found a close correlation between subtype IV subgroups and population geography; thus, all subgroups except c2 were prevalent in particular East Asian populations, with c2 occurring in both Europe and Northeast Asia. From these findings, we conclude that subtype IV of BKV now prevalent in modern humans is derived from a virus that infected ancestral Asians. We introduce two hypotheses to explain how ancestral Asians became infected with subtype IV BKV.