Phylogenetic relationships and differential selection pressures among genotypes of dengue-2 virus
Phylogenetic relationships and differential selection pressures among genotypes of dengue-2 virus
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DOI：
10.1006/viro.2002.1447
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发表时间：
2002-06-20
期刊：
影响因子：
3.7
通讯作者：
Holmes, EC
中科院分区：
文献类型：
--
作者：
Twiddy, SS;Farrar, JJ;Holmes, EC
为了阐明控制登革2型病毒(DEN-2)出现和传播的过程，我们研究了从当地(越南)和全球人口中采样的病毒分离株的进化。我们的系统发育分析结合了147株DEN-2分离株的包膜(E)糖蛋白序列，提供了更完整的病毒多样性图景，其中一种新定义的“Cosmopolitan”基因型几乎分布在全球，另外两种基因型仅限于亚洲。通过分析同义和非同义替换率，我们确定了不同的基因型经历了不同的选择压力，一些证据表明在Cosmopolitan基因型和两个亚洲基因型之一中存在正选择，但是E基因从无序到人类传播的转变并不伴随着E基因的适应性进化，尽管作用于E基因的选择压力与所提出的不同基因型之间的毒力差异之间没有关联，但一些假定选择的氨基酸位点先前涉及到改变病毒的致病力，最显著的是E-390，也可能影响传播性。这些发现对DEN-2病毒的未来传播有一定的影响。(C)2002年埃尔塞维尔科学公司(美国)。
To elucidate the processes controlling the emergence and spread of dengue-2 virus (DEN-2) we examined the evolution of viral isolates sampled from both local (Viet Nam) and global populations. Our phylogenetic analysis, incorporating envelope (E) glycoprotein sequences from 147 isolates of DEN-2, provided a more complete picture of viral diversity, with a newly defined "Cosmopolitan" genotype having a near global distribution and two other genotypes restricted to Asia. By analyzing rates of synonymous and nonsynonymous substitution we determined that genotypes have experienced different selection pressures, with some evidence of positive selection in the Cosmopolitan genotype and one of the two Asian genotypes, but that the transition from sylvatic to human transmission was not accompanied by adaptive evolution of the E gene, Although there was no association between selection pressures acting on the E gene and proposed virulence differences among genotypes, some putatively selected amino acid sites have previously been implicated in changing viral pathogenicity, most notably E-390, and may also affect transmittability. These findings have implications for the future spread of DEN-2. (C) 2002 Elsevier Science (USA).