Guo Wei, Fung Wing K, Shi Ningzhong, Guo Jianhua
Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong, China.
Hum Hered. 2005;60(3):177-80. doi: 10.1159/000090119. Epub 2005 Dec 13.
Admixture linkage disequilibrium (ALD), a phenomenon created by gene flow between genetically distinct populations, has for some time been used as a tool in gene mapping. It is therefore important to analyze the pattern of ALD over generations. In this study we explore two models of admixture: the gradual admixture (GA) model, in which admixture occurs at a variable rate in every generation; and the immediate admixture (IA) model, a special case of the GA model, in which admixture occurs in a single generation. In the case of ALD, the well-known formula of linkage disequilibrium (Delta(t)=(1-r)t Delta(0)) is not applicable under these two models. We note the effect of a random mating population (RMP) to the gametic frequencies from the parental population to the offspring population, and provide the correct formula for ALD.
混合连锁不平衡（ALD）是由遗传上不同的群体之间的基因流动所产生的一种现象，一段时间以来一直被用作基因定位的工具。因此，分析几代人的ALD模式很重要。在本研究中，我们探讨了两种混合模型：渐进混合（GA）模型，其中混合在每一代以可变速率发生；以及即时混合（IA）模型，它是GA模型的一个特例，其中混合发生在单一世代。在ALD的情况下，著名的连锁不平衡公式（Delta(t)=(1-r)t Delta(0)）在这两种模型下并不适用。我们注意到随机交配群体（RMP）对从亲代群体到子代群体的配子频率的影响，并给出了ALD的正确公式。
