The Evolutionary Role of 3D Genome Changes in Sharks and Skates.

Researchers have identified a mutation in an enhancer that regulates the expression of some genes in the developmentally important hox group, which specifies the general body plan in all bilaterally symmetrical animals. The mutation caused the hoxa genes to be active in both the front and back of the pectoral fins of skates, leading to the formation of winglike structures that allowed them to inhabit a different ecological niche. The study shows that changes in the 3D architecture of a genome can cause significant changes in body shape and may serve as a driver of evolution.