Natural variation in chromatin conformation among populations of Drosophila melanogaster

The role of polymorphisms in protein-coding and non-coding regions of the genome during adaptive evolution has been a long-debated subject in evolutionary biology. Although the importance of coding-sequence polymorphisms during evolution has been well-documented, the influence of non-coding regions of the genome on phenotypic diversity and adaptive evolution remains less clear. Enhancers are cis-regulatory elements that dictate gene transcription rates, times, and locations; enhancers are located in noncoding regions and, when active, exhibit an open-chromatin conformation. In the current study, we identified putative enhancers that differ in chromatin conformation among three natural isolates of Drosophila melanogaster from different parts of the world. The genome-wide numbers of enhancers active in some natural isolates—but inactive in others—will provide insight into the amount of raw material available for evolution due to transcriptional regulatory variation.