According to a study by Stanford University School of Medicine, a molecule crucial to stem cell functioning plays a major role in controlling human hair color. The researchers found that the blonde hair, commonly seen in Northern Europeans, is caused by a single change in the DNA that regulates the expression of a gene that encodes a protein called KITLG, also known as stem cell factor. This change affects how much KITLG is expressed in the hair follicles without changing how it is expressed in the body. Interestingly, introducing the change into normally brown-haired laboratory mice yielded an animal with a decidedly lighter coat.
“We’ve been trying to track down the genetic and molecular basis of naturally occurring traits—such as hair and skin pigmentation—in fish and humans to [gain] insight into the general principles by which traits evolve,” said David Kingsley, PhD, professor of developmental biology, in a press statement. “Now we find that one of the most crucial signaling molecules in mammalian development also affects hair color.”
Kingsley, who is also a Howard Hughes Medical Institute investigator, is the senior author of the study, published online on June 1 in Nature Genetics. Research specialist Catherine Guenther, PhD, is the lead author.
