Yokoyama S
J Theor Biol. 1983 Jan 7;100(1):173-80. doi: 10.1016/0022-5193(83)90100-5.
A mathematical model has been developed to study the mechanism of the maintenance of variable numbers of alpha-globin genes in human populations. The model incorporates both selection and unequal crossing-over. The selection is formulated so that a homozygous individual with a double deletion is lethal and a heterozygous individual with a deletion or addition of an alpha-globin gene in a chromosome has decreased fitness. This differs from the previous models of stabilizing selection studied by Ohta (1981) and Takahata (1981). The effect of random genetic drift on the alpha-thalassemia polymorphims has also been studied. It has been shown that, although the results obtained are compatible with the observation of the low frequency of triple alpha-globin loci, it cannot explain the high frequency of single and double deletions in Asian populations. For the latter case, some type of heterozygote advantage may be operating.
已开发出一个数学模型来研究人类群体中α-珠蛋白基因可变数量维持的机制。该模型纳入了选择和不等交换。选择的设定方式是，具有双缺失的纯合个体是致死的，而染色体中α-珠蛋白基因有缺失或增加的杂合个体适合度降低。这与大谷（1981年）和高畑（1981年）研究的先前稳定选择模型不同。还研究了随机遗传漂变对α-地中海贫血多态性的影响。结果表明，虽然所得结果与观察到的三α-珠蛋白基因座低频情况相符，但无法解释亚洲人群中单缺失和双缺失的高频情况。对于后一种情况，可能存在某种类型的杂合子优势在起作用。
