數量性狀基因座定位法在加速失敗時間模式下之應用

Application of Mapping Quantitative Trait Loci on Accelerated Failure Time Models

曾信嘉(Shinn-Jia Tzeng) ； 邱慈緯(Tzu-Wei Chiu)

《作物、環境與生物資訊》 3卷4期 (2006/12) Pp. 317-324

https://doi.org/10.30061/CEB.200612.0004

摘要

大部分數量性狀基因座(QTL)定位的方法被發展，是以常態分配且可完全觀察的表現型資料為主。當表現型屬於失敗時間的資料時，常會有偏斜分配與失去追蹤等問題，使得這些方法可能會不適用。本文針對會有設限失敗時間的表現型資料，提出加速失敗時間模式(accelerated failure time model)來描述QTL對其之影響，應用Diao, Lin and Fei (2004)的EM演算法(expectation maximization algorithm)估計迴歸參數與偵測染色體上的QTL，並由一些模擬研究來評估所建議方法之表現。模擬結果顯示出QTL位置與影響效果的估計是接近不偏的，而且隨著標誌基因個數的增加，所提出用來估計迴歸係數與位置偵測的方法似乎也愈有效率。

關鍵字

加速失敗時間模式 ； EM演算法 ； 區間定位 ； 數量性狀基因座 ； 存活資料

並列摘要

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, Lin and Fei (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 marks increase.

並列關鍵字

Accelerated failure time model ； EM algorithm ； Interval mapping ； QTL ； Survival data