Charlesworth D, Charlesworth B
Department of Ecology and Evolution, University of Chicago, 915 E. 57th St., Chicago, IL, 60637.
Evolution. 1990 Jul;44(4):870-888. doi: 10.1111/j.1558-5646.1990.tb03811.x.
The equilibrium level of inbreeding depression in populations with different selfing rates is studied for models with symmetrical or asymmetrical heterozygous advantage at several loci with partial linkage. As for the case of a single locus, the inbreeding depression caused by loci with heterozygous advantage can be higher for partially selfing populations than for complete outcrossing. The spread of modifier alleles at another locus that affects the selfing rate is studied. The stability of outcrossing populations to invasion by alleles that give increased selfing is found to depend on levels of inbreeding depression being greater than one-half, in accordance with earlier models that assumed a fixed level of inbreeding depression. However, in partially selfing populations the spread of such alleles can be checked by smaller levels of inbreeding depression than one-half, so that they do not always spread to fixation. This is interpreted as being due to associations between the genotypes at the modifier locus and the selected loci, together with increasing inbreeding depression as selfing increases, and does not occur if the inbreeding depression is due to mutation-selection balance.
针对具有部分连锁的多个位点存在对称或不对称杂合优势的模型，研究了不同自交率群体中近亲繁殖衰退的平衡水平。与单个位点的情况一样，具有杂合优势的位点所导致的近亲繁殖衰退，对于部分自交群体而言可能高于完全异交群体。研究了另一个影响自交率的位点上修饰基因座等位基因的传播。发现异交群体对于自交增加的等位基因入侵的稳定性取决于近亲繁殖衰退水平大于二分之一，这与早期假设固定近亲繁殖衰退水平的模型一致。然而，在部分自交群体中，此类等位基因的传播可以通过小于二分之一的近亲繁殖衰退水平来抑制，因此它们并不总是传播至固定状态。这被解释为是由于修饰基因座和选择位点的基因型之间的关联，以及随着自交增加近亲繁殖衰退加剧所致，而如果近亲繁殖衰退是由突变 - 选择平衡引起的，则不会出现这种情况。
