PDF(Pubmed)
Abstract：
Inbreeding depression (ID) is a major selective force during mating system evolution primarily contributed by highly to partially recessive deleterious mutations. Theories suggest that transient genetic association with fitness alleles can be important in affecting the evolution of alleles that modify the selfing rate during its sweep. Nevertheless, empirical tests often focus on the pre-existing genetic association between selfing rate and ID maintained under mutation-selection balance. Therefore, how this standing genetic association is affected by key factors and its impacts on the evolution of selfing remain unclear. I show that as the selection coefficient of deleterious mutations increases, the association between selfing rate and ID declines from positive to negative. These results predict that association between selfing and ID tends to be negative in populations with low selfing rates, while positive in highly selfing populations. Using population genetic and quantitative genetic models, I show that standing genetic associations between selfing rate and fitness alleles can significantly impact the evolution of the mean selfing rate of a population. I present better metrics of population-level ID, which can be calculated based on the correlation coefficient between individual selfing rate and the fitness of selfed and outcrossed offspring.
摘要：
近交抑郁（ID）是交配系统进化过程中的主要选择力，主要是由部分隐性有害突变引起的。理论表明，与适应性等位基因的瞬时遗传关联对于影响等位基因的进化可能很重要，这些等位基因在扫描过程中会改变自交率。然而，经验检验通常集中在自交率和ID之间预先存在的遗传关联，维持在突变选择平衡下。因此,这种常设遗传关联如何受到关键因素的影响及其对自交进化的影响尚不清楚。我表明，随着有害突变的选择系数增加，自交率和ID之间的关联从正下降为负。这些结果预测，自交和ID之间的关联在自交率较低的人群中往往是负的，而在高度自交的人群中呈阳性。利用种群遗传和数量遗传模型，我表明，自交率和适合度等位基因之间的常设遗传关联可以显着影响种群平均自交率的演变。我提出了更好的人口级别ID指标，可以根据个体自交率与自交和异交后代的适应度之间的相关系数来计算。
