西班牙和德國科學(xué)家近日通過研究具有5萬年歷史的尼安德特人DNA,，得出結(jié)論認(rèn)為，至少有一些尼安德特人具有紅色頭發(fā)和白皙皮膚,。相關(guān)論文10月25日在線發(fā)表于《科學(xué)》上,。
領(lǐng)導(dǎo)此次研究的是西班牙巴塞羅那大學(xué)的Carles Lalueza-Fox和德國萊比錫大學(xué)的Holger Römpler。研究人員此次關(guān)注的重點(diǎn)是mc1r基因,，具有較低活性mc1r基因的現(xiàn)代人類容易具有白皙皮膚,，這有利于生活在高緯度的人有效利用有限太陽光合成維生素D。研究人員發(fā)現(xiàn),，此次研究的尼安德特人mc1r基因含有一個(gè)單堿基對的變異,。
研究人員對mc1r基因的功能部分進(jìn)行了多次測序，讓另外的實(shí)驗(yàn)室用新鮮片斷重復(fù)了實(shí)驗(yàn),，并檢測了3700多個(gè)現(xiàn)代人類的mc1r基因序列,，結(jié)果沒有發(fā)現(xiàn)與尼安德特人相同的mc1r基因序列。這表明,，這種序列很可能是尼安德特人獨(dú)有的,。論文合著者、德國馬普學(xué)會進(jìn)化人類學(xué)研究所的Michael Hofreiter說：“如果說現(xiàn)代人類也含有這一序列的話,，那么概率也是極其低的,。”
研究人員隨后將尼安德特人mc1r基因插入人類細(xì)胞，結(jié)果發(fā)現(xiàn)它的活性與白皮膚紅頭發(fā)人類mc1r基因的活性大致相同,。研究人員估計(jì),，至少有1%的尼安德特人擁有這種低活性基因的兩個(gè)副本，這使得他們具有類似現(xiàn)代人的紅頭發(fā),。
Lalueza-Fox和Hofreiter表示,，此次研究表明，蒼白皮膚很可能是在尼安德特人和現(xiàn)代人類之中分別獨(dú)立進(jìn)化的，而不太可能是由二者雜交而來,。
美國中密歇根大學(xué)的人類學(xué)家Rachel Caspari認(rèn)為,，人類皮膚顏色的調(diào)節(jié)是非常復(fù)雜的過程，所以進(jìn)化產(chǎn)生淡色皮膚的方式可能有多種,。她同時(shí)提醒說,，現(xiàn)在還不能排除尼安德特人和現(xiàn)代人類進(jìn)行過遺傳交換的可能性。一種可能性就是,，人類在5萬年前時(shí)具有相關(guān)等位基因,，后來為變異所取代。她說：“對于尼安德特人和現(xiàn)代人類之間的基因流動（gene flow）的觀點(diǎn),，此次研究不能提供支持,，但也不能完全駁倒。”（科學(xué)網(wǎng) 梅進(jìn)/編譯）
原始出處:
Published Online October 25, 2007
Science DOI: 10.1126/science.1147417
Submitted on July 5, 2007
Accepted on October 12, 2007
A Melanocortin 1 Receptor Allele Suggests Varying Pigmentation Among Neanderthals
Carles Lalueza-Fox 1*, Holger Römpler 2, David Caramelli 3, Claudia Stäubert 4, Giulio Catalano 5, David Hughes 6, Nadin Rohland 6, Elena Pilli 3, Laura Longo 7, Silvana Condemi 8, Marco de la Rasilla 9, Javier Fortea 9, Antonio Rosas 10, Mark Stoneking 6, Torsten Schöneberg 4, Jaume Bertranpetit 11, Michael Hofreiter 6*
1 Departament de Biologia Animal, Universitat de Barcelona, Spain.
2 Molecular Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany.; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
3 Laboratorio di Antropologia, Università di Firenze, Italy.
4 Molecular Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany.
5 Laboratorio di Antropologia, Università di Firenze, Italy.; Unitat de Biologia Evolutiva, Universitat Pompeu Fabra, Barcelona, Spain.
6 Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
7 Dipartimento di Scienze Ambientali, Università di Siena, Siena, Italy.
8 Unité d'Anthropologie, CNRS, UMR 6578, Marseille, France.
9 Área de Prehistoria, Universidad de Oviedo, Spain.
10 Departamento de Paleobiología, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain.
11 Unitat de Biologia Evolutiva, Universitat Pompeu Fabra, Barcelona, Spain.
* To whom correspondence should be addressed.
Carles Lalueza-Fox , E-mail: [email protected]
Michael Hofreiter , E-mail: [email protected]
These authors contributed equally to this work.
The melanocortin 1 receptor (MC1R) regulates pigmentation in humans and other vertebrates. Variants of MC1R with reduced function are associated with pale skin color and red hair in humans primarily of European origin. We amplified and sequenced a fragment of the MC1R gene (mc1r) from two Neanderthal remains. Both specimens have a mutation not found in ~3,700 modern humans. Functional analyses show that this variant reduces MC1R activity to a level that alters hair and/or skin pigmentation in humans. The impaired activity of this variant suggests that Neanderthals varied in pigmentation levels, potentially to the scale observed in modern humans. Our data suggest that inactive MC1R variants evolved independently in both modern humans and Neanderthals.
