The human face is as unique as a fingerprint, no one else looks exactly like you. But what is it that makes facial morphology so distinct? Certainly genetics play a major role as evident in the similarities between parents and their children, but what is it in our DNA that fine-tunes the genetics so that siblings – especially identical twins – resemble one another but look different from unrelated individuals? A new study by researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has now shown that gene enhancers – regulatory sequences of DNA that act to turn-on or amplify the expression of a specific gene – are major players in craniofacial development.
…In all, Visel, Attanasio and their colleagues identified more than 4,000 candidate enhancer sequences predicted to be active in fine-tuning the expression of genes involved in craniofacial development, and created genome-wide maps of these enhancers by pin-pointing their location in the mouse genome. The researchers also characterized in detail the activity of some 200 of these gene enhancers and deleted three of them. A majority of the enhancer sequences identified and mapped are at least partially conserved between humans and mice, and many are located in human chromosomal regions associated with normal facial morphology or craniofacial birth defects.