A Genetic Mechanism for Convergent Skin Lightening during Recent Human Evolution

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.

Biocompatible Colloidal Suspensions Based on Magnetic Iron Oxide Nanoparticles: Synthesis, Characterization and Toxicological Profile

“…a * can reach negative or positive values between −60 and + 60, from green to red, this marker being known as redness and is considered an indicator for the presence of the erythema (the higher the values is, the erythema is more intense). b * —yellowness, the coordinate that is related to melanin content from the skin, can be expressed as negative or positive values from −60 (blue) to +60 (yellow; Alaluf et al, 2002; Tzung et al, 2009; Yang et al, 2016). …”

An Unexpectedly Complex Architecture for Skin Pigmentation in Africans

“…rs1800414 in OCA2 in East Asians), whereas other shared effects resulted from similar selective sweeps (e.g. KITLG ) (Miller et al, 2007; Yang et al, 2016). Because African populations have been understudied, the genetic architecture and higher variability of skin pigmentation is poorly understood.…”

Informativeness of dental morphology in ancestry estimation in African Americans

“…The Wilcoxon Signed Rank Test is a nonparametric test used for paired data to test the null hypothesis that a randomly selected value from one sample is equally likely to be less than as it is greater than a randomly selected value from a second sample. This test is appropriate for proportion data and other data types with truncated distributions (e.g., at 0 and 1) (Healy et al, ; Klimentidis & Shriver, ; Yang et al, ). We used this test to determine whether the FI distributions from the dichotomized and nondichotomized dental morphological data were the same, and again to test whether the ancestry distributions produced by these two data forms were the same.…”