Figure 3.

Chimeric enhancer constructs drive different levels of gene expression. (A) To generate chimeric constructs with proximal and distal enhancers from D. mel and D. pse, we first made constructs in which we replaced the endogenous sequence between the two enhancers with a spacer taken from the lambda phage genome. These constructs, shown in orange, do not drive expression levels that are significantly different from the constructs with the endogenous spacer, shown in black and gray (rank sum, p-values > 0.5). (B) We then made chimeric enhancer constructs, which contained the proximal and distal enhancers from different species. These constructs drive significantly different levels of expression from each other (rank sum, p-value = 2.9e-8) and generally drive different levels of expression from the lambda spacer control constructs (rank sum with Bonferroni correction, p-values < 0.02), with the exception of chimera 1 and the D. mel lambda spacer construct (rank sum with Bonferroni correction, p-value = 0.17).