Segregation variance after hybridization of isolated populations.
Segregation variance after hybridization of isolated populations.
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DOI：
10.1017/s0016672300032547
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发表时间：
1994-08
期刊：
影响因子：
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通讯作者：
M. Slatkin;R. Lande
中科院分区：
文献类型：
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作者：
M. Slatkin;R. Lande
我们开发了一个模型来预测增加的遗传方差的数量性状的杂交人口通过交叉两个以前隔离的人口相同的物种。在F2杂种中方差的增加，即“分离方差”，是由每个位点的平均等位基因效应的差异和位点间的连锁不平衡引起的。我们专注于的情况下，字符是添加剂的基础上，字符的平均值并没有在两个人口不同。在这种情况下，预测的分离方差很大程度上取决于对性状遗传基础的假设。如果每个群体中性状的遗传方差可归因于具有许多中等频率的小效应等位基因的基因座，如Lande（1975）模型，则分离方差应随时间线性增加，因为群体是分离的，其速率由有效群体大小的倒数决定。如果遗传变异是由等位基因频率很低的基因座引起的，如图雷利（1984）的纸牌屋模型或巴顿（1990）的多效性有害等位基因模型，那么杂种群体中的分离变异以低得多的速率增加。
We develop a model to predict the increase in genetic variance of a quantitative character in a hybrid population produced by crossing two previously isolated populations of the same species. The increase in variance in the F2 hybrids, the 'segregation variance', is caused by differences in the average allelic effects at each locus and by linkage disequilibrium among loci. We focus on the case in which the character is additively based and the average value of the character does not differ in the two populations. In that case the predicted segregation variance depends strongly on what is assumed about the genetic basis of the character. If the genetic variance of the character in each population is attributable to loci with numerous alleles of small effect that are in moderate frequency, as in Lande's (1975) model, the segregation variance should increase linearly with time since the populations were isolated, at a rate determined by the inverse of the effective population size. If the genetic variance is attributable to loci with alleles in very low frequency, as in Turelli's (1984) house-of-cards model or in Barton's (1990) model of pleiotropic, deleterious alleles, then the segregation variance in the hybrid population increases at a much lower rate.