Epistasis as a source of increased additive genetic variance at population bottlenecks
Epistasis as a source of increased additive genetic variance at population bottlenecks
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DOI：
10.2307/2410645
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发表时间：
1996-06-01
期刊：
影响因子：
3.3
通讯作者：
Routman, EJ
中科院分区：
文献类型：
--
作者：
Cheverud, JM;Routman, EJ
上位性在进化和物种形成中的作用仍然存在争议。我们使用生理上位性的新参数化来检查上位性对群体瓶颈期间加性遗传方差水平的影响。我们发现，所有形式的上位都会增加源自具有中等等位基因频率的初始群体的有限群体的平均加性通用方差。平均加性方差在许多代中持续增加，特别是在人口规模较大的情况下（N = 32 至 64）。在这种情况下，加性上位是加性遗传方差的最有效来源，而显性上位则贡献较小量的加性遗传方差。在加性显性上位性的情况下，加性遗传方差在种群瓶颈之后立即以相对较高的速率下降，并在几代后反弹到更高的水平。提供了基于测量的基因型的小鼠成年体重上位性的经验例子，说明了在群体瓶颈期间上位性对加性遗传方差的不同影响。
The role of epistasis in evolution and speciation has remained controversial. We use a new parameterization of physiological epistasis to examine the effects of epistasis on levels of additive genetic Variance during a population bottleneck. We found that all forms of epistasis increase average additive generic variance in finite populations derived from initial populations with intermediate allele frequencies. Average additive variance continues to increase over many generations, especially Lit larger population sizes (N = 32 to 64). Additive-by-additive epistasis is the most potent source of additive genetic variance in this situation, whereas dominance-by-dominance epistasis contributes smaller amounts of additive genetic variance. With additive-by-dominance epistasis, additive genetic variance decreases at a relatively high rate immediately after a population bottleneck, rebounding to higher levels after several generations. Empirical examples of epistasis for murine adult body weight based on measured genotypes are provided illustrating the varying effects of epistasis on additive genetic variance during population bottlenecks.