Gene enhancers fine-tune craniofacial development

During the search for our doppelgangers in the world, we may miss the question that eludes many of our minds: What exactly makes each face so distinct? It’s common sense that we have eyes, a nose, and a mouth, but how is it possible that we can recognize between hundreds of our friends solely from these features? Geneticist Axel Visel of Berkeley Lab’s Genomics Division has made discoveries in the field that allow us to better answer this question.

A new study at the Berkeley Laboratory showed that gene enhancers, which regulate sequences of DNA and intensify expressions of a specific gene, have an impacting role in the craniofacial development. Currently, the specific roles of the enhancers remain unknown.

Visel, along with Catia Attanasio, who has aided in decoding the regulatory genome, has identified more than 4,000 enhancer sequences predicted to be crucial to adjusting gene expression. They created genome-wide maps of the enhancers by identifying their location in mouse DNA. Additionally, 200 of the gene enhancers were characterized in detail by the researchers.

Some mutation projects, some of which involved the deletion of some enhancers, resulted in a completely different facial structure in mice. This suggested that of the 4,000 plus enhancers that are involved, all of them are some how important for the fine-tuning of facial differentiation.

Visel claims that learning about the existence of these enhancers, identifying their exact location in the human genome, and understanding the general activity pattern in the craniofacial development should help provide a better understanding of the development between genetics and human craniofacial morphology. He also suggests that his results will open doors for human geneticists to look for mutations specific in enhancers that may be active in birth defects. This can ultimately help develop better diagnostic and therapeutic approaches.

Currently, Visel and his collaborators are in the process of improving their genome-wide maps in order to gain additional information about the activity of these enhancer sequences. The team is also working with human geneticists to be able to search for mutations of these enhancer sequences in patients who have birth defects related to craniofacial development.