Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Room 4100, Cambridge, Massachusetts 02138, USA.
Genetics. 2009 Aug;182(4):1141-57. doi: 10.1534/genetics.108.089474. Epub 2009 May 27.
We present a Moran-model approach to modeling general multiallelic selection in a finite population and show how it may be used to develop theoretical models of biological systems of balancing selection such as plant gametophytic self-incompatibility loci. We propose new expressions for the stationary distribution of allele frequencies under selection and use them to show that the continuous-time Markov chain describing allele frequency change with exchangeable selection and Moran-model reproduction is reversible. We then use the reversibility property to derive the expected allele frequency spectrum in a finite population for several general models of multiallelic selection. Using simulations, we show that our approach is valid over a broader range of parameters than previous analyses of balancing selection based on diffusion approximations to the Wright-Fisher model of reproduction. Our results can be applied to any model of multiallelic selection in which fitness is solely a function of allele frequency.
我们提出了一种 Moran 模型方法来模拟有限群体中的一般多等位基因选择，并展示了如何将其用于开发平衡选择的生物系统的理论模型，如植物配子体自交不亲和位点。我们提出了在选择下的等位基因频率的平稳分布的新表达式，并利用它们来证明描述具有可交换选择和 Moran 模型繁殖的等位基因频率变化的连续时间马尔可夫链是可逆的。然后，我们使用可逆性来推导出有限群体中几种一般多等位基因选择模型的预期等位基因频率谱。通过模拟，我们表明与基于繁殖的 Wright-Fisher 模型的扩散近似的平衡选择的先前分析相比，我们的方法在更广泛的参数范围内是有效的。我们的结果可应用于任何仅由等位基因频率决定适合度的多等位基因选择模型。
