Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11790, United States of America.
Theor Popul Biol. 2022 Aug;146:61-70. doi: 10.1016/j.tpb.2022.06.001. Epub 2022 Jul 13.
The egalitarian allotment of gametes to each allele at a locus (Mendel's law of segregation) is a near-universal phenomenon characterizing inheritance in sexual populations. As exceptions to Mendel's law are known to occur, one can investigate why non-Mendelian segregation is not more common using modifier theory. Earlier work assuming sex-independent modifier effects in a random mating population with heterozygote advantage concluded that equal segregation is stable over long-term evolution. Subsequent investigation, however, demonstrated that the stability of the Mendelian scheme disappears when sex-specific modifier effects are allowed. Here I derive invasion conditions favoring the repeal of Mendelian law in mixed and obligate selfing populations. Oppositely-directed segregation distortion in the production of male and female gametes is selected for in the presence of overdominant fitness. The conditions are less restrictive than under panmixia in that strong selection can occur even without differential viability of reciprocal heterozygotes (i.e. in the absence of parent-of-origin effects at the overdominant fitness locus). Generalized equilibria are derived for full selfing.
在一个基因座上，每个等位基因的配子平等分配（孟德尔分离定律）是描述有性种群遗传的普遍现象。由于已知孟德尔分离定律存在例外，因此可以使用修饰理论来研究为什么非孟德尔分离不太常见。早期的工作假设在具有杂合优势的随机交配群体中，修饰因子的作用是独立于性别的，并得出结论，均等分离在长期进化中是稳定的。然而，随后的研究表明，当允许特定于性别的修饰因子作用时，孟德尔方案的稳定性就会消失。在这里，我推导出了在混合和强制自交种群中有利于废除孟德尔定律的入侵条件。在超显性适合度的情况下，雄性和雌性配子产生的相反方向的分离扭曲被选择。这些条件比泛群集的条件限制更少，因为即使没有互异合子的生存力差异（即在超显性适合度基因座上没有亲本来源效应），也可以发生强烈的选择。我还推导出了完全自交的广义平衡。
