Genetic constraints and the adaptive evolution of rabies virus in nature
Genetic constraints and the adaptive evolution of rabies virus in nature
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DOI：
10.1006/viro.2001.1271
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发表时间：
2002-01-20
期刊：
影响因子：
3.7
通讯作者：
Bourhy, H
中科院分区：
文献类型：
--
作者：
Holmes, EC;Woelk, CH;Bourhy, H
我们采用分子进化的方法来研究狂犬病毒在自然界中的物种适应。选择压力的最大似然分析显示，天然病毒分离株的核蛋白（N）和糖蛋白（G）基因受到高度限制，特别是在非同义位点，与实验室传代病毒中观察到的较高的非同义进化率相反。阳性选择仅在G基因胞外域的单个氨基酸位点-位置183处发现。狂犬病病毒天然分离株的非同义进化率低，可能是由于需要在宿主内的多种细胞类型中复制而施加的限制，这反过来又促进了跨物种传播，或者是因为病毒蛋白不受免疫选择的影响。使用欧洲病毒分离株流行病学史上的已知日期，我们估计狂犬病病毒中核苷酸替换的总体速率与在其他RNA病毒中观察到的相似。假设同义变化的平均速率在物种之间没有变化，我们估计，狂犬病病毒基因型1目前的遗传多样性可能只出现在过去的500年。(C)2002年爱思唯尔科学。
We used a molecular evolutionary approach to investigate the species adaptation of rabies virus in nature. A maximum likelihood analysis of selection pressures revealed that the nucleoprotein (N) and glycoprotein (G) genes of natural viral isolates were highly constrained, especially at nonsynonymous sites, in contrast to the higher rates of nonsynonymous evolution observed in viruses subject to laboratory passage. Positive selection was only found at a single amino acid site-position 183 in the ectodomain of the G gene. The low rate of nonsynonymous evolution in natural isolates of rabies virus may be due to constraints imposed by the need to replicate in multiple cell types within the host, which in turn facilitates cross-species transmission, or because viral proteins are not subject to immune selection. Using known dates in the epidemiologic history of European viral isolates, we estimated that overall rates of nucleotide substitution in rabies virus were similar to those observed in other RNA viruses. Assuming that the average rate of synonymous change does not vary among species, we estimated that the current genetic diversity in lyssavirus genotype 1 may have arisen only during the last 500 years. (C) 2002 Elsevier Science.