A method for single trait quantitative trait loci estimation in F₂ crosses between outbred lines

A new approach for Quantitative Trait Loci (QTL) analysis in designed experiments is investigated using a mixed model framework through the modification of segment mapping techniques. Allele effects are modelled in the F1 generation allowing the estimation of additive substitution effects while accounting for QTL segregation within lines as well as differences in mean QTL effects between lines. The resulting approach is called F1 origin mapping where additive genetic variances are estimated via Restricted Maximum Likelihood (REML) and allele effects are modelled using Best Linear Unbiased Prediction (BLUP). By coupling this new approach with the computer program ASREML, F1 origin mapping provides a flexible and efficient tool for QTL studies. A simple genetic simulation study is presented to illustrate the method and its properties.