A single-letter change in the genetic code is enough to generate blond hair in humans, in dramatic contrast to our dark-haired ancestors. A new analysis by Howard Hughes Medical Institute scientists has pinpointed that change, which is common in the genomes of Northern Europeans, and shown how it fine-tunes the regulation of an essential gene.
"This particular genetic variation in humans is associated with blond hair, but it isn't associated with eye color or other pigmentation traits," says David Kingsley, an HHMI investigator at Stanford University who led the study. "The specificity of the switch shows exactly how independent color changes can be encoded to produce specific traits in humans." Kingsley and his colleagues published their findings in the journal Nature Genetics.
Kingsley says a handful of genes likely determine hair color in humans, however, the precise molecular basis of the trait remains poorly understood. "I think you will see a lot more of this type of study in the future, leading to a much better understanding of both the molecular basis of human diversity and of the susceptibility or resistance to many common diseases," Kingsley said.
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