Estimation of deleterious-mutation parameters in natural populations.
Estimation of deleterious-mutation parameters in natural populations.
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发表时间：
1996-09
期刊：
影响因子：
3.3
通讯作者：
Hong Wen Deng;Michael Lynch
中科院分区：
文献类型：
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作者：
Hong Wen Deng;Michael Lynch
自发有害突变的发生率和平均效应是育种系统进化和小种群灭绝脆弱性的重要决定因素。然而，很少有人尝试估计此类突变的特性，并且已经进行的那些研究是极其劳动密集型的，依赖于长期的实验室突变积累实验。我们提出了后一种方法的替代方案。对于适应度遗传方差是选择突变平衡结果的群体，远交世代的平均适应度和适应度遗传方差可以表示为基因组突变率、平均纯合效应和新突变的平均显性系数的简单函数。使用适应度平均值和遗传方差的经验估计，可以求解这些表达式以获得有害突变参数的联合估计。我们采用计算机模拟来评估估计器的偏差程度，并就该技术的应用提出一些一般性建议。我们的程序为从广泛的系统发育范围的物种中获得有害突变的特性估计提供了一些希望，并为测试维持遗传变异适应性的替代模型的有效性提供了一种机制。
The rate and average effects of spontaneous deleterious mutations are important determinants of the evolution of breeding systems and of the vulnerability of small populations to extinction. Nevertheless, few attempts have been made to estimate the properties of such mutations, and those studies that have been performed have been extremely labor intensive, relying on long-term, laboratory mutation-accumulation experiments. We present an alternative to the latter approach. For populations in which the genetic variance for fitness is a consequence of selection-mutation balance, the mean fitness and genetic variance of fitness in outbred generations can be expressed as simple functions of the genomic mutation rate, average homozygous effect and average dominance coefficient of new mutations. Using empirical estimates for the mean and genetic variance of fitness, these expressions can then be solved to obtain joint estimates of the deleterious-mutation parameters. We employ computer simulations to evaluate the degree of bias of the estimators and present some general recommendations on the application of the technique. Our procedures provide some hope for obtaining estimates of the properties of deleterious mutations from a wide phylogenetic range of species as well as a mechanism for testing the validity of alternative models for the maintenance of genetic variance for fitness.