A Research Plan for the Identification of QTL

Abstract Text: Past attempts to find mutations causing variation in quantitative traits important in livestock production have largely been thwarted by the small effects that individual mutations have and the LD between the causal mutation and other polymorphisms. However, we now have more powerful tools, such as genome sequence on individual animals, that increase our power to identify the  mutations underlying quantitative trait loci (QTL). Here we review the statistical methods used to analyze association studies and the biological information that might be used to discriminate between alternative sites as the causal mutation. The problem caused by LD can be reduced by using multiple breeds and by fitting all sequence variants simultaneously with a Bayesian model in which many variants are expected to have no effect. Biological information can be incorporated into the statistical analysis  to estimate  the probability that each sequence variant has an effect.

Keywords: QTL, milk, biology