A Genetic Mechanism for Convergent Skin Lightening during Recent Human Evolution

Mol Biol Evol. 2016 May;33(5):1177-87. doi: 10.1093/molbev/msw003. Epub 2016 Jan 6.

Abstract

Skin lightening among Eurasians is thought to have been a convergence occurring independently in Europe and East Asia as an adaptation to high latitude environments. Among Europeans, several genes responsible for such lightening have been found, but the information available for East Asians is much more limited. Here, a genome-wide comparison between dark-skinned Africans and Austro-Asiatic speaking aborigines and light-skinned northern Han Chinese identified the pigmentation gene OCA2, showing unusually deep allelic divergence between these groups. An amino acid substitution (His615Arg) of OCA2 prevalent in most East Asian populations-but absent in Africans and Europeans-was significantly associated with skin lightening among northern Han Chinese. Further transgenic and targeted gene modification analyses of zebrafish and mouse both exhibited the phenotypic effect of the OCA2 variant manifesting decreased melanin production. These results indicate that OCA2 plays an important role in the convergent skin lightening of East Asians during recent human evolution.

Keywords: East Asians; OCA2; adaptation; natural selection; pigmentation genes; skin lightening.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • African Continental Ancestry Group / genetics
  • Alleles
  • Amino Acid Substitution
  • Asian Continental Ancestry Group / genetics*
  • Biological Evolution
  • Child
  • Ethnic Groups / genetics
  • European Continental Ancestry Group / genetics
  • Evolution, Molecular
  • Female
  • Gene Frequency
  • Genetic Association Studies / methods
  • Genetic Variation
  • Genetics, Population / methods
  • Haplotypes
  • Humans
  • Male
  • Membrane Transport Proteins / blood
  • Membrane Transport Proteins / genetics*
  • Membrane Transport Proteins / metabolism
  • Polymorphism, Single Nucleotide
  • Selection, Genetic
  • Skin Pigmentation / genetics*
  • Skin Pigmentation / physiology
  • Young Adult

Substances

  • Membrane Transport Proteins
  • OCA2 protein, human