The full EM algorithm for the MLEs of QTL effects and positions and their estimated variances in multiple-interval mapping
The full EM algorithm for the MLEs of QTL effects and positions and their estimated variances in multiple-interval mapping
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DOI：
10.1111/j.1541-0420.2005.00327.x
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发表时间：
2005-06-01
期刊：
影响因子：
1.9
通讯作者：
Chen, ZH
中科院分区：
文献类型：
--
作者：
Chen, ZH
DNA分子标记完整遗传连锁图的出现，使得在实验生物中定位数量性状基因座（QTL）的系统研究成为可能。多区间作图法为利用遗传标记进行QTL定位提供了一种合适的方法。然而，所涉及的计算的有效算法仍有待开发。在本文中，一个完整的EM算法的QTL效应和位置的最大似然估计的同时计算。基于EM的公式推导出计算观察到的Fisher信息矩阵。将完整EM算法与Kao和Zeng（1997，Biometrics 53，653-665）开发的ECM算法进行比较。通过仿真研究证明了反演观测Fisher信息矩阵作为极大似然估计方差矩阵的有效性。
The advent of complete genetic linkage maps of DNA markers has made systematic studies of mapping quantitative trait loci (QTL) in experimental organisms feasible. The method of multiple-interval mapping provides an appropriate way for mapping QTL using genetic markers. However, efficient algorithms for the computation involved remain to be developed. In this article, a full EM algorithm for the simultaneous computation of the MLEs of QTL effects and positions is developed. EM-based formulas are derived for computing the observed Fisher information matrix. The full EM algorithm is compared with an ECM algorithm developed by Kao and Zeng (1997, Biometrics 53, 653-665). The validity of the inverted observed Fisher information matrix as an estimate of the variance matrix of the MLEs is demonstrated by a simulation study.