WHY EPISTASIS IS IMPORTANT FOR SELECTION AND ADAPTATION
WHY EPISTASIS IS IMPORTANT FOR SELECTION AND ADAPTATION
复制标题
DOI：
10.1111/evo.12214
复制
发表时间：
2013-12-01
期刊：
影响因子：
3.3
通讯作者：
Hansen, Thomas F.
中科院分区：
文献类型：
--
作者：
Hansen, Thomas F.
生物体是由成千上万的基因组成的，这些基因以复杂的方式相互作用。尽管如此，进化的数学理论仍然被一个基因接一个基因的观点所主导，在这种观点中，基因被假定为具有相同的效果，而不管遗传背景如何。基因相互作用，或上位性，在某些理论发展中发挥作用，如重组的进化，生殖隔离和渠化，但在我们的表型适应的标准解释中却明显缺失。这种缺失在数量遗传学领域是最令人困惑的，尽管它有多基因的观点和上位性的详细统计表示，但没有发现基因相互作用在进化中的重要作用。相反，有一个广泛的共识，即上位性是进化惰性的，我们需要知道的是遗传方差的加性成分来预测进化动力学。这种观点可能有根源的方便，但也在理论上的结果表明，来自上位方差分量的选择的反应是不是永久性的，将衰减时，选择放松。我表明，这些结果与概念混乱有关，并且作为关于上位性对选择反应和适应的重要性的一般性陈述具有误导性。
Organisms are built from thousands of genes that interact in complex ways. Still, the mathematical theory of evolution is dominated by a gene-by-gene perspective in which genes are assumed to have the same effects regardless of genetic background. Gene interaction, or epistasis, plays a role in some theoretical developments such as the evolution of recombination, reproductive isolation, and canalization, but is strikingly missing from our standard accounts of phenotypic adaptation. This absence is most puzzling within the field of quantitative genetics, which, despite its polygenic perspective and elaborate statistical representation of epistasis, has not found a single important role for gene interaction in evolution. To the contrary, there is a widespread consensus that epistasis is evolutionary inert, and that all we need to know to predict evolutionary dynamics is the additive component of the genetic variance. This view may have roots in convenience, but also in theoretical results showing that the response to selection derived from epistatic variance components is not permanent and will decay when selection is relaxed. I show that these results are tied to a conceptual confusion, and are misleading as general statements about the significance of epistasis for the selection response and adaptation.