Evolution of recombination due to random dirift
Evolution of recombination due to random dirift
复制标题
DOI：
10.1534/genetics.104.032821
复制
发表时间：
2005-04-01
期刊：
影响因子：
3.3
通讯作者：
Otto, SP
中科院分区：
文献类型：
--
作者：
Barton, NH;Otto, SP
在接受选择的有限群体中，即使选择对所有基因座起独立作用(即乘性作用)，平均而言，遗传漂移也会产生负连锁不平衡。负不平衡减少了适应度的方差，因此，根据费舍尔(1930)的基本定理，减缓了平均适应度的增长速度。增加重组的修饰物消除了阻碍选择的负面不平衡，从而通过“搭便车”增加了频率。因此，有限群体中连锁不平衡的随机波动有利于提高重组率的进化，即使在基因座之间没有上位性相互作用的情况下，甚至在最初没有不平衡的情况下也是如此。在本文中开发的方法允许ITS量化作用于修饰等位基因的选择强度，从而增加有限种群中的重组。分析表明，随机产生的连锁不平衡确实选择了增加重组，这一结果得到了蒙特卡罗模拟的证实。当基因座之间的连锁紧密时，当有益等位基因从低频率上升到高频率时，当群体规模较小时，对促进重组的修饰物的选择是最高的。
In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection acts independently (i.e., multiplicatively) upon all loci. Negative disequilibrium reduces the variance in fitness and hence, by FISHER'S (1930) fundamental theorem, slows the rate of increase in mean fitness. Modifiers that increase recombination eliminate the negative disequilibria that impede selection and consequently increase in frequency by "hitchhiking." Thus, stochastic fluctuations in linkage disequilibrium in finite populations favor the evolution of increased rates of recombination, even in the absence of epistatic interactions among loci and even when disequilibrium is initially absent. The method developed within this article allows its to quantity the strength of selection acting on a modifier allele that increases recombination in a finite population. The analysis indicates that stochastically generated linkage disequilibria do select for increased recombination, a result that is confirmed by Monte Carlo simulations. Selection for a modifier that increases recombination is highest when linkage among loci is tight, when beneficial alleles rise from low to high frequency, and when the population size is small.