Evolutionary relationships among Astroviridae
Evolutionary relationships among Astroviridae
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DOI：
10.1099/0022-1317-83-6-1397
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发表时间：
2002-06-01
影响因子：
3.8
通讯作者：
Goudsmit, J
中科院分区：
文献类型：
--
作者：
Lukashov, VV;Goudsmit, J
为了研究星状病毒之间的进化关系，收集了星状病毒科成员的所有可用序列。系统发育分析区分了两个根深蒂固的群体：一个包括哺乳动物星状病毒，绵羊星状病毒是一个离群值，另一个包括鸟类星状病毒。所有的病毒物种以及人类星状病毒的血清型都代表了树中的个体谱系。所有人类病毒都聚集在一起，并与非人类病毒分开，这表明它们具有共同的进化起源，并反对正在进行的动物到人类的传播。哺乳动物星状病毒的分支顺序与其宿主物种的分支顺序完全相反，这表明至少有两种跨物种传播，涉及猪，猫和人类，可能通过中间宿主。同义（Ds）与非同义（Da）的距离分析表明，负选择是占主导地位的星状病毒的进化，与Ds：Da的比例高达46的比较最密切相关的病毒。基于Ds的所有开放阅读框架（ORF）的系统发育分析导致树状结构的丢失，病毒物种--在ORF 2中，甚至是人类星状病毒的血清型--几乎从一个节点分支出来，表明它们在古代是分离的。针对非同义替换的强选择，其数量少，因此，不能证明谱系之间最近分离，以及最古老的可用人类星状病毒株（1971年）远离其血清型4的共同节点的位置，表明erotype内多样化起源于更早的日期。
To study the evolutionary relationships among astroviruses, all available sequences for members of the family Astroviridae were collected. Phylogenetic analysis distinguished two deep-rooted groups: one comprising mammalian astroviruses, with ovine astrovirus being an outlier, and the other comprising avian astroviruses. All virus species as well as serotypes of human astroviruses represented individual lineages within the tree. All human viruses clustered together and separately from non-human viruses, which argue for their common evolutionary origin and against ongoing animal-to-human transmissions. The branching order of mammalian astroviruses was exactly the opposite of that of their host species, suggesting at least two cross-species transmissions involving pigs, cats and humans, possibly through intermediate hosts. Analysis of synonymous (Ds) versus non-synonymous (Da) distances revealed that negative selection is dominating in the evolution of astroviruses, with the Ds:Da ratios being up to 46 for the comparisons of the most closely related viruses. Phylogenetic analyses of all open reading frames (ORFs) based on Ds resulted in the loss of tree structures, with virus species - and in ORF2, even serotypes of human astroviruses - branching out from virtually a single node, suggesting their ancient separation. The strong selection against non-synonymous substitutions, the low number of which is, therefore, not proof of a recent separation between lineages, together with the position of the oldest available human astrovirus strain (1971) far from the common node of its serotype 4, suggest that intraserotype diversification originates from an earlier date.