as a locus with an individual contribution of at least 5% of the total variance of the trait. Since the Bayesian analysis method used does not provide traditional LOD scores or p-values, the results were used to provide a count of the number of times a particular genomic position was accepted as the position of a QTL during an update of the model (a "hit"). Using the intensity ratio (IR), these estimated numbers of hits were then compared with the number that would be expected by chance, given the specified prior distributions. In map interval i, the IRi was calculated as follow: IRi = hi/ei, where hi was the observed number of hits in map interval i and ei, the expected number of hits in map interval i. The expected number of hits ei being (E(n)/L) × bi × I. E(n) was the expected number of QTLs in an iteration in the analysis, obtained from the prior distribution, L was the total map length, bi was the bin width, and I was the number of iterations. IRs were computed using a 2-cM bin and a total map length of 3000 cM.
