Evolutionary diversification of protein-coding genes of hantaviruses
Evolutionary diversification of protein-coding genes of hantaviruses
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DOI：
10.1093/oxfordjournals.molbev.a026254
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发表时间：
2000-10-01
影响因子：
10.7
通讯作者：
Friedman, R
中科院分区：
文献类型：
--
作者：
Hughes, AL;Friedman, R
汉坦病毒（布尼亚病毒科：汉坦病毒）的S，M和L基因的系统发育分析显示，三个分化良好的分支对应于病毒寄生在三个亚科（鼠科，Arvicolinae，和Sigmodontinae）的啮齿动物家庭鼠科。在M和L基因的根树中，以鼠亚科为宿主的病毒与以Arvicolinae和Sigmodontinae为宿主的病毒形成外群。这一同源性与基于线粒体细胞色素B序列的鼠亚科同源性相一致，支持汉坦病毒至少自这三个亚科的共同祖先以来与哺乳动物宿主共进化的假设，这可能发生在大约5000万年前。核衣壳蛋白（由S基因编码）在寄生于三个亚科的病毒中的分化方式使得高频率的氨基酸残基电荷变化发生在分子的高变（HV）部分，并且非同义核苷酸差异导致HV区域的氨基酸电荷变化发生的频率显著高于随机取代下的预期。沿着的证据表明，至少在一些汉他病毒的HV区是一个目标的宿主抗体和已知的重要性，带电残基在确定抗体表位，这些结果表明，在HV区的变化可能代表适应宿主特异性特征的免疫反应。
Phylogenetic analyses of the S, M, and L genes of the hantaviruses (Bunyaviridae: Hantavirus) revealed three well-differentiated clades corresponding to viruses parasitic on three subfamilies (Murinae, Arvicolinae, and Sigmodontinae) of the rodent family Muridae. In rooted trees of M and L genes, the viruses with hosts belonging to Murinae formed an outgroup to those with hosts in Arvicolinae and Sigmodontinae. This phylogeny corresponded with a phylogeny of the murid subfamilies based on mitochondrial cytochrome b sequences, supporting the hypothesis that hantaviruses have coevolved with their mammalian hosts at least since the common ancestor of these three subfamilies, which probably occurred about 50 MYA. The nucleocapsid protein (encoded by the S gene) differentiated among the viruses parasitic on the three subfamilies in such a way that a high frequency of amino acid residue charge changes occurred in a hypervariable (HV) portion of the molecule, and nonsynonymous nucleotide differences causing amino acid charge changes in the HV region occurred significantly more frequently than expected under random substitution. Along with evidence that at least in some hantaviruses the HV region is a target for host antibodies and the known importance of charged residues in determining antibody epitopes, these results suggest that changes in the HV region may represent adaptation to host-specific characteristics of the immune response.