Matsuda Hirokazu, Iwaisaki Hiroaki
Course of Environmental Management Science, Graduate School of Science and Technology, Niigata University, Japan.
J Appl Genet. 2002;43(2):193-207.
This paper described a method for predicting additive effects of a cluster of tightly linked QTLs for outbred populations of animals in the situation where the QTLs are located on a chromosome segment surrounded by multiple linked DNA markers. We present a mixed model method for best linear unbiased prediction (conditional to the marker data) of the additive effects of the QTL-cluster and of the remaining QTLs unlinked to the marker linkage group. This method takes into consideration the identity-by-descent proportion (IBDP) for the particular chromosomal segment, in contrast to some other methods which use IBD probabilities at one specific location. In this method, fully informative data on different flanking markers is used to calculate the values of the expectations of the IBDPs (EIBDPs) between gametes for animals to be evaluated. Then the expected values are used as the elements of the gametic relationship matrix required in the best linear unbiased prediction. Giving a small numerical example, we illustrate how the present method can be used for the prediction of the QTL-cluster effects and for genetic evaluation of animals in outbred populations. A computational strategy is discussed on the basis of the calculation of the EIBDPs and the inverted gametic relationship matrix in complex pedigrees.
本文描述了一种预测远交群体动物紧密连锁QTL簇加性效应的方法，该情况是QTL位于由多个连锁DNA标记包围的染色体片段上。我们提出了一种混合模型方法，用于对QTL簇以及与标记连锁群不连锁的其余QTL的加性效应进行最佳线性无偏预测（以标记数据为条件）。与其他一些在一个特定位置使用同源相同比例（IBD）概率的方法不同，该方法考虑了特定染色体片段的同源相同比例（IBDP）。在该方法中，利用不同侧翼标记的完全信息数据来计算待评估动物配子间IBDP期望值（EIBDP）的值。然后，将这些期望值用作最佳线性无偏预测所需的配子亲缘关系矩阵的元素。通过给出一个小的数值示例，我们说明了如何使用本方法预测QTL簇效应以及对远交群体中的动物进行遗传评估。基于复杂系谱中EIBDP和逆配子亲缘关系矩阵的计算，讨论了一种计算策略。
