Being born with natural blonde hair is part of a very slight genetic change, as a team of researchers from Stanford University in California (USA) has just discovered.
Experts have found that only the substitution of one of the four letters of DNA at a key point in the human genome is what changes the activity of a particular gene that leads precisely to blonde hair . Thus, some of these small changes or single nucleotic polymorphisms (SNPs) represent variants in skin and hair color.
The researchers focused on the KITLG gene, closely linked to northern European populations. They used laboratory mice that they created with two genetic variations of human DNA : one with the blonde gene variant and another by changing one of the bases, inserting only one copy of each variant into the mice's DNA. Thus, the mice with the first variant were much lighter in skin and hair than the others.
The results of the study, which have been published in the journal Nature Genetics , explain that changes in blonde hair are therefore not linked to all body tissues, but rather that this change is merely superficial , which "explains why the effect of KITLG is specific for the hair but not for the eyes and skin ”, says Fan Liu, Genetics expert at Erasmus MC in Rotterdam (The Netherlands).
