Out of billions of people, no two faces are exactly the same. How does this happen? Researchers from Stanford School of medicine say that "enhancers" present in the junk DNA follow an origami-like design while constructing the face, using simple instructions to make an intricate object.
During the early stages of the embryo development, a set of cells called neural crest cells drives a process that is required to make the head and face of the baby. Initially an embryo looks like a sheet of flat cells. This sheet eventually folds to form a tube, much of which becomes the spinal column and the brain. The face of the infant develops from an end of this tube. Researchers were studying what guides this specific process.
"We were interested in identifying the portions of the human genome that are responsible for the behavior of the neural crest," said one of the study authors Joanna Wysocka, PhD, from Stanford School of Medicine.
Wysocka and her colleagues discovered that certain genetic modification can determine which cells become the face. These DNA modifications called "enhancers" can change the shape of a face by manipulating the activity of the genes that are involved in the face-making process.
Surprisingly, these enhancers weren't present along with the genes that code for the development of face, but were present in non-coding or "junk DNA".
"What's really emerging is the idea that one cell type's junk is another cell type's treasure," said Wysocka.
Researchers also found that these enhancers can be active or silent depending on the stage of development of the cell and its position. The enhancers function like origami where slight changes in the folds can create different objects, says a news release from Stanford School of Medicine.
Researchers say that the study will act as a resource material for future research on facial development, especially the ones that focus on facial abnormalities like cleft palate where sheets of cells during early development don't fuse properly and leave a gap or a cleft
"By identifying neural crest enhancers, our study can tell other investigators where to look for genetic variants that can explain these facial abnormalities or even why each human being has a unique face," said Alvaro Rada Iglesias, PhD, first author of the study.
Published by Medicaldaily.com