随机效应模型下标记-QTL连锁分析方法

Linkage analysis between marker and QTL under the frame work of random effect model

在QTL随机模型的框架内,通过对QTL方差组分的最大似然估计,进行家畜一般系谱群体的QTL标记连锁分析,研究中同时考虑了性状遗传力和QTL效应的不同水平对QTL定位效果的影响。结果表明,采用QTL随机效应模型可以有效地进行标记QTL间的连锁分析并可获得较高的检验功效,QTL位置与效应参数的估计均在合理的范围内;同时,性状遗传力和QTL方差贡献对QTL定位准确度和功效均有较大的影响,随着性状遗传力和QTL方差贡献的增大,参数估计的准确性和检验功效提高。固定性状遗传力的情况下(h2=0.1),QTL效应由0.1→0.5时,相应的检验功效由17%提高到49%;当遗传力和QTL效应均提高到0.5时,QTL检验功效最高达到88%。

Methodology of linkage analysis by means of QTL variance using maximum likelihood based on the framework of a random QTL effect model was present in the paper. The effects of putative QTL were treated as random effect in the model. The factors of influencing QTL mapping （e. g. QTL effect and herftability） were simulated in our study too. The results showed that random QTL model have a good behavior for QTL mapping, and have a higher statistical power. The estimated QTL parameters are close to the expected values with reasonable standard errors in our study. In addition, the accuracy of QTL mapping depended on the effect of putative quantitative trait loci and the value of heritability. With the increase of QTL effect and heritability, the accuracy of QTL mapping improved slightly. When the heritability and QTL effect were 0.5 respectively, the power attained maximum （88%）.