Doerge R W, Churchill G A
Biometrics Unit, Cornell University, Ithaca, New York 14853, USA.
Genetics. 1996 Jan;142(1):285-94. doi: 10.1093/genetics/142.1.285.
The problem of detecting minor quantitative trait loci (QTL) responsible for genetic variation not explained by major QTL is of importance in the complete dissection of quantitative characters. Two extensions of the permutation-based method for estimating empirical threshold values are presented. These methods, the conditional empirical threshold (CET) and the residual empirical threshold (RET), yield critical values that can be used to construct tests for the presence of minor QTL effects while accounting for effects of known major QTL. The CET provides a completely nonparametric test through conditioning on markers linked to major QTL. It allows for general nonadditive interactions among QTL, but its practical application is restricted to regions of the genome that are unlinked to the major QTL. The RET assumes a structural model for the effect of major QTL, and a threshold is constructed using residuals from this structural model. The search space for minor QTL is unrestricted, and RET-based tests may be more powerful than the CET-based test when the structural model is approximately true.
检测那些负责解释主要数量性状基因座（QTL）无法解释的遗传变异的微小数量性状基因座（QTL）问题，对于完整剖析数量性状具有重要意义。本文提出了两种基于排列的方法来估计经验阈值的扩展方法。这些方法，即条件经验阈值（CET）和残差经验阈值（RET），产生的临界值可用于构建检测微小QTL效应存在的检验，同时考虑已知主要QTL的效应。CET通过对与主要QTL连锁的标记进行条件设定，提供了一种完全非参数的检验。它允许QTL之间存在一般的非加性相互作用，但其实际应用仅限于基因组中与主要QTL不连锁的区域。RET假设了一个主要QTL效应的结构模型，并使用该结构模型的残差构建一个阈值。微小QTL的搜索空间不受限制，当结构模型近似正确时，基于RET的检验可能比基于CET的检验更具威力。
