Sepsid even-skipped Enhancers Are Functionally Conserved in Drosophila Despite Lack of Sequence Conservation
Figure 7
Evolutionary fate of binding sites is dependent on their proximity to other sites.
Binding sites in the stripe 2, stripe 3+7, and MHE enhancers were classified as “overlapping” if they shared at least one base pair with a site for a different factor, “close” if the nearest base of another site (for a different factor) is within 10 bp, and “isolated” if neither condition is met. Binding sites in D. melanogaster were classified as non-conserved, minimally conserved (only within melanogaster subgroup), highly conserved (within 12 sequenced Drosophila species) and extremely conserved (12 Drosophila and 6 sepsids). (A) The distribution of conservation scores as a function of binding-site proximity shows overlapping and close sites are more likely to be highly or extremely conserved than isolated sites. (B) The fraction of each conservation category in different proximity groups again shows that extremely and highly conserved sites are strongly enriched for overlapping and close binding sites.