Ultraviolet radiation (UV radiation) triggers greater synthesis of several compounds, including pro-opiomelanocortin (POMC), α-MSH, and ACTH, the result being increased eumelanin production. In addition, other genetic and environmental factors can affect hair color in humans for instance, mutations in the melanocortin 1 receptor (MC1R) gene can lead to red or auburn hair, and exposure to ultraviolet radiation can damage hair and alter its pigmentation.
ĭifferent hair color phenotypes arise primarily as a result of varying ratios of these two pigments in the human population, although Europeans show the greatest range in pigmentation overall. Inside the melanocytes, tyrosine is converted into L-DOPA and then L-dopaquinone, which in turn is formed into pheomelanin or eumelanin.
Two types of pigment give hair its color, black-brown eumelanin and reddish-brown/reddish-yellow pheomelanin, synthesized by melanocytes. identified 13 DNA variations across 11 different genes that could be used to predict hair color. Regulatory DNA is believed to be closely involved in pigmentation in humans in general, and a 2011 study by Branicki et al.
DARK COPPER HAIR FULL
The full genetic basis of hair color is complex and not fully understood. See also: Human genetic variation and Race and genetics
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