A critical evaluation of the effect of population size and phenotypic measurement on QTL detection and localization using a large F2 murine mapping population

Genetics and Molecular Biology

Xinmin Li²  Richard J Quigg²  Jian Zhou²  Shizhong Xu¹  Godfred Masinde¹  Subburaman Mohan¹  David J. Baylink¹ 

[1] ,University of Chicago Division of Biological Sciences Functional Genomics FacilityChicago IL ,USA

关键词: QTL mapping;    mice;    detection power;    population size;    phenotypic measurement;   

DOI  :  10.1590/S1415-47572006000100030

来源: SciELO

【 摘 要 】

Population size and phenotypic measurement are two key factors determining the detection power of quantitative trait loci (QTL) mapping. We evaluated how these two controllable factors quantitatively affect the detection of QTL and their localization using a large F2 murine mapping population and found that three main points emerged from this study. One finding was that the sensitivity of QTL detection significantly decreased as the population size decreased. The decrease in the percentage logarithm of the odd score (LOD score, which is a statistical measure of the likelihood of two loci being lied near each other on a chromosome) can be estimated using the formula 1 - n/N, where n is the smaller and N the larger population size. This empirical formula has several practical implications in QTL mapping. We also found that a population size of 300 seems to be a threshold for the detection of QTL and their localization, which challenges the small population sizes commonly-used in published studies, in excess of 60% of which cite population sizes <300. In addition, it seems that the precision of phenotypic measurement has a limited capacity to affect detection power, which means that quantitative traits that cannot be measured precisely can also be used in QTL mapping for the detection of major QTL.

【 授权许可】

CC BY   
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