The placement of significant SNPs within the horse cytochrome P 450 genes. A. The horse CYP3A93-96 genes align to CYP3A5 (human and several other species, Bos CYP3A4) and downstream of the horse cluster, CYP3A6. The –logP for individual SNPs in the region is indicted. The green line represents genome wide significance. Linkage disequilibrium as D’ is shown. B. Shows the Fst nalysis of Chromosome 13 with the region of CYP3A indicated (arrow). The green dotted line represents 2 standard deviations from the mean Fst value for chromosome 13.