The full EM algorithm for the MLEs of QTL effects and positions and their estimated variances in multiple-interval mapping.
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.
Chen
Zehua
Z
Department of Statistics and Applied Probability, National University of Singapore, Singapore 117543. stachenz@nus.edu.sg
D000465:Algorithms; D002874:Chromosome Mapping / Q000379:methods*; D003198:Computer Simulation; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D008040:Genetic Linkage; D005819:Genetic Markers; D005838:Genotype; D016013:Likelihood Functions; D015810:Linkage Disequilibrium; D008126:Lod Score; D008957:Models, Genetic; D015233:Models, Statistical; D010641:Phenotype; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D012984:Software
D005819:Genetic Markers