在所有的動(dòng)物里,，人類是最會(huì)出汗的,。最近哈佛大學(xué)和復(fù)旦大學(xué)的研究者合作發(fā)現(xiàn)，東亞人特有的一個(gè)基因變異使得東亞人更容易出汗,。
研究者通過研究一個(gè)被稱為EDAR370A的東亞人特有的基因變異,，發(fā)現(xiàn)這個(gè)變異出現(xiàn)在3萬多年前的東亞,，并且改變了東亞人祖先的汗腺和毛發(fā)的密度、毛發(fā)粗細(xì)及牙齒特征,。由于這個(gè)變異具備與環(huán)境適應(yīng)的生存優(yōu)勢,，它在人群中的比例迅速增加。該研究成果作為封面論文發(fā)表于2月14日出版的國際權(quán)威學(xué)術(shù)期刊《細(xì)胞》(Cell)雜志,。
該課題組的汪思佳教授介紹說,，這個(gè)基因變異約三萬年前產(chǎn)生于東亞人群，最終在中國漢族人群中達(dá)到近95%,。復(fù)旦大學(xué)的團(tuán)隊(duì)通過分析2500名漢族志愿者,，發(fā)現(xiàn)具有這個(gè)變異的個(gè)體的汗腺密度高了約15%，毛發(fā)更粗,，而且牙齒形狀也有變化,。哈佛大學(xué)的合作者通過動(dòng)物研究證實(shí)，這個(gè)基因變異確實(shí)會(huì)影響汗腺和毛發(fā)的發(fā)育,。
論文通訊作者之一,、復(fù)旦大學(xué)現(xiàn)代人類學(xué)教育部重點(diǎn)實(shí)驗(yàn)室主任金力教授指出，東亞人的祖先3萬多年前來到東亞時(shí),，最先到達(dá)東南亞,。出汗能力的提高，使得我們的祖先能夠更好地適應(yīng)濕熱環(huán)境而生存下去,。所以,，這個(gè)基因變異是東亞人類適應(yīng)新環(huán)境的產(chǎn)物，而這種對(duì)環(huán)境的適應(yīng)性進(jìn)化正是產(chǎn)生當(dāng)代人群間差異的重要機(jī)制之一,。金力教授強(qiáng)調(diào)說,，這次研究揭示，單個(gè)基因變異可以同時(shí)影響人類的多個(gè)形態(tài)特征,。所以,，為數(shù)不多的基因變異可能導(dǎo)致東方人與其他人種的形態(tài)差異。
這個(gè)研究的結(jié)果,，對(duì)發(fā)現(xiàn)決定東亞人群特征的形成具有重要的意義,。該團(tuán)隊(duì)將繼續(xù)從多學(xué)科角度進(jìn)一步研究，最終揭示不同人種形態(tài)差異的生物學(xué)機(jī)制,。（生物谷Bioon.com）
DOI:10.1016/j.cell.2013.01.016
PMC:
PMID:
Modeling Recent Human Evolution in Mice by Expression of a Selected EDAR Variant
Yana G. Kamberov, Sijia Wang, Jingze Tan, Pascale Gerbault, Abigail Wark, Longzhi Tan, Yajun Yang, Shilin Li, Kun Tang, Hua Chen, Adam Powell, Yuval Itan, Dorian Fuller, Jason Lohmueller, Junhao Mao, Asa Schachar, Madeline Paymer, Elizabeth Hostetter, Elizabeth Byrne, Melissa Burnett, Andrew P. McMahon, Mark G. Thomas, Daniel E. Lieberman, Li Jin, Clifford J. Tabin, Bruce A. Morgan, Pardis C. SabetiSee
Highlights
Selected East Asian EDAR allele, 370A, emerged in central China ～30,000 years ago
Hair, sweat, and mammary glands are altered in a 370A knockin mouse model
The novel effect of 370A on mouse sweat gland density is recapitulated in humans
Summary
An adaptive variant of the human Ectodysplasin receptor, EDARV370A, is one of the strongest candidates of recent positive selection from genome-wide scans. We have modeled EDAR370A in mice and characterized its phenotype and evolutionary origins in humans. Our computational analysis suggests the allele arose in central China approximately 30,000 years ago. Although EDAR370A has been associated with increased scalp hair thickness and changed tooth morphology in humans, its direct biological significance and potential adaptive role remain unclear. We generated a knockin mouse model and find that, as in humans, hair thickness is increased in EDAR370A mice. We identify new biological targets affected by the mutation, including mammary and eccrine glands. Building on these results, we find that EDAR370A is associated with an increased number of active eccrine glands in the Han Chinese. This interdisciplinary approach yields unique insight into the generation of adaptive variation among modern humans.
