Genus Coltivirus (family Reoviridae):: genomic and morphologic characterization of Old World and New World viruses
Genus Coltivirus (family Reoviridae):: genomic and morphologic characterization of Old World and New World viruses
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DOI：
10.1007/s007050200005
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发表时间：
2002-01-01
影响因子：
2.7
通讯作者：
de Lamballerie, X
中科院分区：
文献类型：
--
作者：
Attoui, H;Jaafar, FM;de Lamballerie, X
我们报告了欧洲Eyach（EYA）病毒（Coltivirus属，呼肠孤病毒科）的基因组和形态学研究，并与美国科罗拉多蜱热（CTF）病毒（该属的模式种）进行了比较分析。先前建立的，但遥远的，这些病毒之间的抗原关系得到加强的遗传学研究结果（同源基因的存在，55和88%之间的氨基酸同一性，相似的保守的末端基序，在第9节的两种病毒的可疑通读现象）和不可区分的超微形态。此外，推测的组成型修饰酶活性被怀疑是由同源病毒蛋白进行的（RNA依赖的RNA聚合酶，甲基/鸟苷酰转移酶，NTR）。这些发现，连同对东南亚分离株基因组的比较分析，支持虫媒病毒的最新分类，其中12个dsRNA片段属于两个不同的属（Coltivirus属和Seadornavirus属），并提出了关于Coltivirus进化起源的有趣问题。先前提出的假设，即EYA病毒是从欧洲引入的祖先病毒与来自北美的兔形目动物的迁移，这意味着美洲和欧洲分离株之间的分歧日期超过5000万年前（MYA）。该分析首次提出了病毒dsRNA基因组的进化速率，发现其为10（-8）至10（-9）个突变/nt/年，与dsDNA基因组的速率相似。
We report a genomic and morphologic study of the European Eyach (EYA) virus (genus Coltivirus, family Reoviridae) and a comparative analysis with the American Colorado tick fever (CTF) virus (the type species of the genus). The previously established, but distant, antigenic relationship between these viruses was strengthened by genetic findings (presence of cognate genes, amino acid identity between 55 and 88%, similar conserved terminal motifs, suspected read-through phenomenon in segment 9 of both viruses) and by indistinguishable ultramicroscopic morphologies. Moreover, putative constitutive modifying enzyme activities were suspected to be carried out by homologous viral proteins (RNA-dependent RNA polymerase, methyl/guanylyl transferase, NTPase).These findings, together with the comparative analysis to genomes of southeast Asian isolates, support the recent classification of arboviruses with 12 segments of dsRNA within two distinct genera (genus Coltivirus and genus Seadornavirus) and raise interesting questions about the evolutionary origins of coltiviruses. The previously proposed hypothesis that EYA virus was derived from an ancestral virus introduced in Europe with the migration of lagomorphs from North-America, would imply a divergence date between American and European isolates of over 50 million years ago (MYA). This analysis allows for the first time to propose an evolutionary rate for virus dsRNA genomes which was found to be in the order of 10(-8) to 10(-9) mutations/nt/year, a rate similar to that of dsDNA genomes.