Figure 2. Results of the selection test for two gene sets.

(a) Effect directions for cis-eQTLs of mitochondria-related genes in liver. A consistent bias is seen for the B6 alleles to upregulate expression. A lower-bound estimate for the number of genes with cis-regulation under lineage-specific selection is the difference in height between the two bars (numbers in green). (b) Effect directions for cis-eQTLs of adult locomotory behavior-related genes in liver. A consistent bias is seen for the CAST alleles to upregulate expression. This does not imply that the expression changes in liver are relevant for this trait, as the effect is seen in all three tissues, and thus is not tissue-specific.