Certainly genetics play a major role as evident in the similarities between parents and their children, but the researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) wanted to know 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.
"Our results suggest it is likely there are thousands of enhancers in the human genome that are somehow involved in craniofacial development. We don't know yet what all of these enhancers do, but we do know that they are out there and they are important for craniofacial development," Axel Visel, a geneticist with Berkeley Lab's Genomics Division who led this study said.
While some genetic defects responsible for craniofacial pathologies such as clefts of the lip or palate have been identified, the genetic drivers of normal craniofacial variation have been poorly understood.
To learn whether gene enhancers can have the same long-distance impact on craniofacial development, Visel and a multinational team of collaborators studied transgenic mice.
The study is published in journal Science.