偵測基因表現值最小變化量的多變量排列方法之研究

A Study on the Multivariate Permutation Test to Detect the Minimal Fold Changes of Gene Expression Levels

邱詩婷(Shih-Ting Chiu)

指導教授 ： 劉仁沛

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.01008

摘要

傳統的假設檢定法利用檢定兩組樣本差異是否等於零來鑑定基因是否有顯著表現，但卻沒有考慮到具有生物意義的倍數變化量，然而在生物領域中基因表現的倍數變化超過某些定值即認定該基因是有表現的。相較於傳統的假設檢定法，2006年由戴家彥碩士論文提出一個區間假設的雙單尾檢定法，此方法不僅能考慮到生物意義亦能更準確地鑑別出有顯著表現的基因。在此我們將進一步將區間假設的雙單尾檢定法推展到無母數領域，以區間假設為基礎，應用多變量排列作出可以偵測基因表現值最小變化量的非介量檢定方法，探討其決策程序、整體型一錯誤、平均檢定力以及型一誤差。
模擬結果顯示在足夠的陣列重複數之下，區間假設檢定方法相較於其它傳統假設檢定方法，不僅整體與平均型一錯誤較低，檢定力亦比傳統的單尾檢定方法來得好，而非介量的多元排列檢定法能進ㄧ步改善這種區間假設檢定。

關鍵字

倍數變化 ； 區間假設檢定 ； 雙單尾檢定法 ； 多元排列檢定法 ； 整體型一錯誤 ； 平均型一錯誤 ； 檢定力

並列摘要

The traditional hypothesis for identification of differentially expressed genes fails to take the biological meaning fold changes into consideration. However, a gene is differentially expressed if its fold change exceeds a threshold value in biological field. Compared with the traditional hypothesis of equality, the two one-sided tests procedure based on interval hypothesis（Liu, et al, 2007）not only consider the minimal biologically meaningful expression but truly identify the differentially expressed genes. To continue the research, we will apply multivariate permutation test to the interval hypothesis. Based on this proposed method, we conduct a simulation study to investigate its power, overall type I error and average type I error when the normal assumption of expression levels is in doubt.
The simulation results indicate that because of lower overall type I error and average type I error and higher average power, the interval hypothesis works better than the traditional hypothesis of equality when there are enough replicates in array. And the multivariate permutation test which is a non-parametric approach could improve the ability of identifying gene expression with interval hypothesis.

並列關鍵字

Fold change ； Interval hypothesis ； Two one-sided tests ； Multivariate permutation ； Power ； Overall and Average Type I error

參考文獻

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