单倍型在QTL检测中的应用研究

A Study on Detection of QTL by Applying Haplotype

【目的】探索连锁不平衡分析在定位致病基因、检测QTL(Quantitative Trait Locus)中的应用。【方法】本研究从国际人类基因组单体型图谱计划数据库采集了69个Y染色体上的遗传标记和269个样本,研究了单倍型分析在QTL检测中的优势及应用策略。【结果】在连锁程度较低的情况下,用单标记分析方法,侧翼标记对功能位点的捕捉率为零,而在单倍型分析中两位点组合的捕捉效率达到了33.3%、三位点组合的捕捉效率达到了66.7%、四位点组合的捕捉效率为71.4%。【结论】建立在单倍型分析基础上的相关性分析,明显优于常规的单标记分析。本试验对采用单倍型分析方法检测QTL的研究能起到一定的指导作用。

[Objective] Linkage disequilibrium been extensively applied in gene mapping and QTL detection. [Method] This study investigated the applied strategy of haplotype analysis in the QTL detection and analyzed its superiority. Genotype data of 69 markers from Y chromosome in 269 human being individuals was sampled from databank released early this year. [Result] Haplotypes were then constructed and one hypothetic QTL locus was given. Capture efficiency of the QTL by haplotype method was investigated. In low degree of linkage disequilibrium, the result showed that the capture efficiency of QTL was zero when analyzing the flanking markers using single marker analysis method. When two, three and four flanking markers were used for haplotype analysis, the efficiency to capture the QTL were 33.3%, 66.7%, and 71.4%, respectively. [Conclusion] For the QTL detection, the association analysis based on haplotype was significantly more powerful than the analysis based on single marker. This study will benefit the research that uses haplotype analysis method to detect QTL.