Mutation-biased adaptation in a protein NK model.
Mutation-biased adaptation in a protein NK model.
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DOI：
10.1093/molbev/msl064
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发表时间：
2006-10
影响因子：
10.7
通讯作者：
A. Stoltzfus
中科院分区：
文献类型：
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作者：
A. Stoltzfus
负责系统性差异的基因组和蛋白质组组成的进化趋势已被归因于GC：AT突变偏置的背景下，中性进化或选择作用于基因组组成。有一种可能性被忽略了，大概是因为它既不是现代综合论的一部分，也不是中性理论的一部分，那就是突变可能会对适应施加方向性的偏见。本文通过在称为“NK”模型的抽象蛋白质适应度景观上模拟适应性步行期间GC：AT偏好对氨基酸组成的影响来探索这种可能性。结果表明，适应并不排除突变偏向的进化。在完全没有中性进化的情况下，一个适度的GC：AT偏差的现实幅度可以取代适应的轨迹在一个突变有利的方向，这样的程度，氨基酸组成是有偏见的实质性和持久的。因此，对进化模式的突变解释不需要以中性进化为前提。
Evolutionary trends responsible for systematic differences in genome and proteome composition have been attributed to GC:AT mutation bias in the context of neutral evolution or to selection acting on genome composition. A possibility that has been ignored, presumably because it is part of neither the Modern Synthesis nor the Neutral Theory, is that mutation may impose a directional bias on adaptation. This possibility is explored here with simulations of the effect of a GC:AT bias on amino acid composition during adaptive walks on an abstract protein fitness landscape called an "NK" model. The results indicate that adaptation does not preclude mutation-biased evolution. In the complete absence of neutral evolution, a modest GC:AT bias of realistic magnitude can displace the trajectory of adaptation in a mutationally favored direction, to such a degree that amino acid composition is biased substantially and persistently. Thus, mutational explanations for evolved patterns need not presuppose neutral evolution.