Facial and cranial shapes are formed through variations of genes according to new study. Scientists say this may bring enlightenment to facial defects like the cleft palate.
A team of international scientists found a way to determine thousands of small clusters of genetic material that plays an important role in developing facial and cranial features. Even though the experiments were done on mice, the researchers believe that the development of the human face progress in a similar manner.
"Somewhere in there there must be that blueprint that defines what our face looks like," said lead author Prof. Axel Visel of Joint Genome Institute at California’s Lawrence Berkeley National Laboratory.
However, the facial and cranial variations in mice are not easy to detect. "The way we can get around this is to use CT scans to study the shapes of the skulls of these mice. We take them and scan their heads. then we can measure the shape of the skull of these mice and we can do this in a very precise way," explained Prof. Visel.
Visel and his colleagues conducted the test on mice by using the 4,000 genome “enhancers” which seem to be influencing facial appearances. These minute DNA stretches appear to work by turning the genes on and off, like a switch. Out of these 4,000 mice genome, the 200 enhancers were traceable to which specific parts of the face and skull they have influence on.
They also tested the extent of the role of these enhancers by removing three of these enhancers from a group of mice and observing their development against those with complete genetic switches.
Using the CT scans, the scientists learned that variations were present but hardly noticeable. They observed though that there were variations in terms of facial and cranial shapes. Some of the mice had longer skulls, some shorter while some had faces that are wider or narrower than others.
According to Prof Visel, "What this really tells us is that this particular switch also plays a role in development of the skull and can affect what exactly the skull looks like," he explained.
The new study was published in the Oct. 24 issue of Science.
