Genome-wide scans for CHCM. Main effect QTL are shown for single-locus genome-wide scans with sex as an additive covariate in the 12 crosses indicated (top left of each panel). Cross abbreviations are defined in Table 1. Horizontal dashed lines on each panel represent significant (P = .05, top line) and suggestive (P = .63, bottom line) LOD scores as determined by 1000 permutations. For C3xD, the single dashed line represents the suggestive level, as no significant QTL were identified in this cross. x-axis, chromosomes 1 through X with the relative spacing representative of the relative length of each chromosome and marker locations shown by tick marks. y-axis, LOD score.