Application of Mapping Quantitative Trait Loci on Accelerated Failure Time Models.

• Main Authors: Tzu-Wei Chiu, 邱慈緯
• Other Authors: Shinn-Jia Tzeng
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/14031361166269515135

碩士 === 國立嘉義大學 === 農學研究所 === 96 === ABSTRACT Most of approaches for mapping quantitative trait loci (QTL) are well developed for normally distributed and completely observed phenotypes. These approaches may not be applicable when the phenotype belongs to the failure time, which has a skewed distribution and is often loss to follow-up. This paper proposes the accelerated failure time model to describe the effect of QTL based on censored failure-time phenotypes.Applying the EM algorithm (expectation maximization algorithm) of Diao et al. (2004) to estimate regression parameters and search the entire chromosome for QTL, some simulation studies are presented to evaluate the performance of the proposed methods. Results from the simulated data indicate that the estimator of the QTL location and the estimators of the QTL effects have little bias, and that the proposed method may be more efficient in estimating regression parameters and detecting QTL as the numbers of markers increase.