Division of Biological Sciences, University of Kansas, Lawrence, Kansas 66045.
Genetics. 1979 Sep;93(1):217-36. doi: 10.1093/genetics/93.1.217.
Analytic solutions are obtained for the equilibria of a simple two-locus, heterotic selection model with mixed selfing and random outcrossing. Two general phenomena are possible, depending upon the viabilities and the degree of selfing: (1) Negative disequilibrium potential, under which only gametic disequilibrium is possible; and (2) positive disequilibrium potential, which can result in permanent gametic disequilibrium provided that linkage is sufficiently tight. Under random mating (s = 0), these two situations correspond to negative and positive additive epistasis, respectively. With partial self-fertilization, however, this is no longer true, and a more appropriate measure of gametc disequilibrium potential, Delta(s), is introduced. A numerically aided examination of the model results in the discovery of two new properties of partial selfing with selection: (1) With negative disequilibrium potential (Delta(s) < 0), the equilibrium mean fitness increases with increasing recombination. With positive disequilibrium potential (Delta(s) > 0), the opposite is true. (2) Gametic disequilibrium can increase or decrease as the degree of selfing is increased. Therefore, it is apparent that partial selfing and linkage are not analogous as regards the maintenance of disequilibrium.
对于一个具有混合自交和随机杂交的简单两基因座杂种优势选择模型，我们得到了其平衡态的解析解。有两种普遍现象可能出现，这取决于活力和自交程度：（1）负不平衡势，在这种情况下，只有配子不平衡是可能的；（2）正不平衡势，只要连锁足够紧密，就可以导致永久的配子不平衡。在随机交配（s=0）下，这两种情况分别对应于负和正的加性上位性。然而，对于部分自交，情况不再如此，因此引入了一个更合适的配子不平衡势的度量，Delta(s)。通过对模型的数值辅助检验，发现了部分自交与选择的两个新特性：（1）在负不平衡势（Delta(s) < 0）下，平衡平均适合度随着重组的增加而增加。在正不平衡势（Delta(s) > 0）下，情况正好相反。（2）随着自交程度的增加，配子不平衡可以增加或减少。因此，很明显，部分自交和连锁在维持不平衡方面并不是类似的。
