01:37pm Thursday 17 August 2017

Scientists discover key contribution to Melanesian blonde hair colour

The findings, published in Science, reveal a functional genetic variant which has led the islanders to have simultaneously the darkest skin pigmentation outside of Africa and the highest prevalence of blonde hair outside of Europe.

High-resolution images available at: http://www.cultivatingdiversity.org/solomon-photos/

Researchers studying pigmentation in the South Pacific have uncovered a key genetic contribution to hair colour. The findings, published in Science, reveal a functional genetic variant which has led the islanders to have simultaneously the darkest skin pigmentation outside of Africa and the highest prevalence of blonde hair outside of Europe.

Human skin and hair colour varies considerably both within and among populations. Previous studies have shown that pigmentation is largely heritable but also suggest it has evolved to adapt to the sun’s ultraviolet rays — with populations near the equator possessing darker skin and hair colour.  However, the Melanesian population of the Solomon Islands, East of Papua New Guinea, differs from this trend.

The research, co-led by Dr Nic Timpson from the Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology at the University of Bristol and researchers at Stanford University in the US, sought to find out what has caused these islanders to possess such discordant patterns of pigmentation, some of the greatest in the world.

The team took samples from a pool of Melanesian participants, 43 with blonde hair and 42 with dark hair, and carried out genetic analysis to compare their genomes. The results showed that the across the whole genome, one key gene region contained the variation responsible for differences in the cells that produce darkening pigmentation, or melanocytes.

Dr Timpson, Lecturer in Genetic Epidemiology from the University’s School of Social and Community Medicine, said: “Naturally blonde hair is a surprisingly unusual trait in humans which is typically associated with people from Scandinavian and Northern European countries. Our findings help explain the fascinating differences in these physical characteristics, but also underline the importance of genetic mapping using isolated populations to help shed new light on the epidemiology of disease.”

“Whether this genetic variation is due to evolution or a recent introgression requires further investigation, but this variant explains over 45 per cent of the variance in hair colour in the Solomons.”

The study, entitled ‘Melanesian blond hair is caused by an amino acid change in TYRP1’ is published in Science [3 May 2012] and funded by the MRC and a Wenner-Gren Foundation for Anthropological Research grant.

Ends

Notes to editors:

For a copy of the paper or to arrange an interview please contact Caroline Clancy, Press Officer, University of Bristol, tel: +44 (0)117 928 8086, mobile +44 (0)7776 170238, email: caroline.clancy@bristol.ac.uk

Images

A selection of high-resolution images of the Solomon Islanders are available at the following URL:

http://www.cultivatingdiversity.org/solomon-photos/

Paper: Melanesian blond hair is caused by an amino acid change in TYRP1

Eimear E. Kenny (1*) Nicholas J. Timpson (2*) Martin Sikora (1) Muh-Ching Yee (1)

Andres Moreno Estrada (1) Celeste Eng (3) Scott Huntsman (3) Esteban Gonzalez Burchard (3) Mark Stoneking (4) Carlos D. Bustamante (1†) Sean Myles (1,5†)

    1.     Department of Genetics, Stanford University, Stanford, USA.
    2.     Medical Research Council (MRC) Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol.
    3.     Department of Bioengineering and Therapeutic Sciences and Medicine, University of California, San Francisco, USA.
    4.     Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Germany.
    5.     Department of Plant and Animal Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada.

Medical Research Council

For almost 100 years the Medical Research Council has improved the health of people in the UK and around the world by supporting the highest quality science. The MRC invests in world-class scientists. It has produced 29 Nobel Prize winners and sustains a flourishing environment for internationally recognised research. The MRC focuses on making an impact and provides the financial muscle and scientific expertise behind medical breakthroughs, including one of the first antibiotics penicillin, the structure of DNA and the lethal link between smoking and cancer. Today MRC funded scientists tackle research into the major health challenges of the 21st century. www.mrc.ac.uk

Issued by the Public Relations Office, Communications Division, University of Bristol


Share on:
or:

Health news