Ritland Kermit
Department of Botany, University of Toronto, Toronto, Ontario, M5S 3B2, Canada.
Evolution. 1996 Jun;50(3):1062-1073. doi: 10.1111/j.1558-5646.1996.tb02347.x.
A marker-based method for studying quantitative genetic characters in natural populations is presented and evaluated. The method involves regressing quantitative trait similarity on marker-estimated relatedness between individuals. A procedure is first given for estimating the narrow sense heritability and additive genetic correlations among traits, incorporating shared environments. Estimation of the actual variance of relatedness is required for heritability, but not for genetic correlations. The approach is then extended to include isolation by distance of environments, dominance, and shared levels of inbreeding. Investigations of statistical properties show that good estimates do not require great marker polymorphism, but rather require significant variation of actual relatedness; optimal allocation generally favors sampling many individuals at the expense of assaying fewer marker loci; when relatedness declines with physical distance, it is optimal to restrict comparisons to within a certain distance; the power to estimate shared environments and inbreeding effects is reasonable, but estimates of dominance variance may be difficult under certain patterns of relationship; and any linkage of markers to quantitative trait loci does not cause significant problems. This marker-based method makes possible studies with long-lived organisms or with organisms difficult to culture, and opens the possibility that quantitative trait expression in natural environments can be analyzed in an unmanipulative way.
本文提出并评估了一种基于标记的方法，用于研究自然种群中的数量遗传特征。该方法涉及将数量性状相似性对个体间标记估计的亲缘关系进行回归分析。首先给出了一个程序，用于估计狭义遗传力以及包含共享环境的性状间加性遗传相关性。遗传力估计需要实际亲缘关系方差的估计值，但遗传相关性估计则不需要。然后将该方法扩展到包括环境距离隔离、显性作用和共享近交水平。对统计特性的研究表明，良好的估计并不需要高度的标记多态性，而是需要实际亲缘关系有显著变化；最优分配通常倾向于以检测较少标记位点为代价对许多个体进行采样；当亲缘关系随物理距离下降时，将比较限制在一定距离内是最优的；估计共享环境和近交效应的能力是合理的，但在某些关系模式下，显性方差的估计可能会很困难；并且标记与数量性状位点的任何连锁都不会导致重大问题。这种基于标记的方法使得对长寿生物或难以培养的生物进行研究成为可能，并开启了以非操纵方式分析自然环境中数量性状表达的可能性。
