title: Bayesian shrinkage analysis of quantitative trait Loci for dynamic traits.
abstract: Many quantitative traits are measured repeatedly during the life of an organism. Such traits are called dynamic traits. The pattern of the changes of a dynamic trait is called the growth trajectory. Studying the growth trajectory may enhance our understanding of the genetic architecture of the growth trajectory. Recently, we developed an interval-mapping procedure to map QTL for dynamic traits under the maximum-likelihood framework. We fit the growth trajectory by Legendre polynomials. The method intended to map one QTL at a time and the entire QTL analysis involved scanning the entire genome by fitting multiple single-QTL models. In this study, we propose a Bayesian shrinkage analysis for estimating and mapping multiple QTL in a single model. The method is a combination between the shrinkage mapping for individual quantitative traits and the Legendre polynomial analysis for dynamic traits. The multiple-QTL model is implemented in two ways: (1) a fixed-interval approach where a QTL is placed in each marker interval and (2) a moving-interval approach where the position of a QTL can be searched in a range that covers many marker intervals. Simulation study shows that the Bayesian shrinkage method generates much better signals for QTL than the interval-mapping approach. We propose several alternative methods to present the results of the Bayesian shrinkage analysis. In particular, we found that the Wald test-statistic profile can serve as a mechanism to test the significance of a putative QTL.
authors: School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 201101, People's Republic of China.
authors: Runqing
authors: R
authors: Yang
authors: Shizhong
authors: S
authors: Xu
mesh_terms: D001499:Bayes Theorem; D003433:Crosses, Genetic; D007700:Kinetics; D008433:Mathematics; D008957:Models, Genetic; D040641:Quantitative Trait Loci