Cyp6g1 expression levels. Shown is the relative expression in adult females of all strains as determined by microarray experiments. All eight European strains contain the Accord insertion and a duplication of the Cyp6g1 gene (white bars), whereas only three of the eight African strains have the insertion/duplication (gray bars). The remaining five African strains have neither the Accord insertion, nor the Cyp6g1 duplication (black bars). Expression levels of all three groups are significantly different from each other (Mann-Whitney test, P < 0.05 for all comparisons).