Evolutionary Mirages: Selection on Binding Site Composition Creates the Illusion of Conserved Grammars in Drosophila Enhancers (original) (raw)
Figure 4
A deletion bias leads to clustering of sites and the apparent conservation of clustered sites.
(A) The distribution of spacer lengths between binding sites during simulations in which 0% (black), 20% (light green), and 40% (dark green) of mutation events are indels with a 3∶2 deletion∶insertion bias. (B) The percent probability that a deletion event affecting a given binding site is accepted by our selective process for adjacent sites (Adj; sites that are touching) or far sites (Far; those with a spacer of at least twenty bases to the nearest neighboring site). (C) The distribution of the average age of binding sites as a function of their distance to their nearest neighbor shows that clustered sites appear more conserved than isolated sites, even though no such selection was applied in the simulations.