THE USE OF MULTIPLE MARKERS IN A BAYESIAN METHOD FOR MAPPING QUANTITATIVE TRAIT LOCI

Information on multiple linked genetic markers was used in a Bayesian method for the statistical mapping of quantitative trait loci (QTL). B ayesian parameter estimation and hypothesis testing were implemented v ia Markov chain Monte Carlo algorithms. Variables sampled were the aug mented data (marker-QTL genotypes, polygenic effects), an indicator va riable for linkage or nonlinkage, and the parameters. The parameter ve ctor included allele frequencies at the markers and the QTL, map dista nces of the markers and the QTL, QTL substitution effect, and polygeni c and residual variances. The criterion for QTL detection was the marg inal posterior probability of a QTL being located on the chromosome ca rrying the markers. The method was evaluated empirically by analyzing simulated granddaughter designs consisting of 2000 sons, 20 related si res, and their ancestors.