Domingo E, Escarmís C, Sevilla N, Moya A, Elena S F, Quer J, Novella I S, Holland J J
Centro de Biología Molecular "Severo Ochoa" Universidad Autónoma, Madrid, Spain.
FASEB J. 1996 Jun;10(8):859-64. doi: 10.1096/fasebj.10.8.8666162.
A hallmark of RNA genomes is the error-prone nature of their replication and retrotranscription. The major biochemical basis of the limited replication fidelity is the absence of proofreading/repair and postreplicative error correction mechanisms that normally operate during replication of cellular DNA. In spite of this unique feature of RNA replicons, the dynamics of viral populations seems to follow the same basic principles that classical population genetics has established for higher organisms. Here we review recent evidence of the profound effects that genetic bottlenecks have in enhancing the deleterious effects of Muller's ratchet during RNA virus evolution. The validity of the Red Queen hypothesis and of the competitive exclusion principle for RNA viruses are viewed as the expected result of the highly variable and adaptable nature of viral quasispecies. Viral fitness, or ability to replicate infectious progeny, can vary a million-fold within short time intervals. Paradoxically, functional and structural studies suggest extreme limitations to virus variation. Adaptability of RNA viruses appears to be based on the occupation of very narrow portions of sequence space at any given time.
RNA基因组的一个标志是其复制和逆转录过程中容易出错的特性。复制保真度有限的主要生化基础是缺乏通常在细胞DNA复制过程中起作用的校对/修复和复制后错误校正机制。尽管RNA复制子有这一独特特征，但病毒群体的动态似乎遵循经典群体遗传学为高等生物所确立的相同基本原理。在此，我们综述了近期的证据，即遗传瓶颈在RNA病毒进化过程中对增强穆勒棘轮的有害效应具有深远影响。红皇后假说和RNA病毒竞争排斥原理的有效性被视为病毒准种高度可变和适应性本质的预期结果。病毒适应性，即复制感染性后代的能力，可在短时间间隔内变化百万倍。矛盾的是，功能和结构研究表明病毒变异存在极大限制。RNA病毒的适应性似乎基于在任何给定时间占据序列空间中非常狭窄的部分。
