Y染色体是人类进化最快染色体

Y染色体是人类进化最快染色体
作者：David C. Page 来源：《自然》 发布时间：2010-1-18 10:43:51


据《中国日报》报道，虽然男人很多时候都被女人念叨说笨，但是相信不少男人看到以下这条新闻之后乐开了花：美国《自然》杂志网站1月13日刊发的一项研究报告显示，决定男人之所以是男人的Y染色体是人类所有基因中进化最快的染色体。

进化比其他基因快2%

据报道，科学家通过将人类的基因与最像人类的“近亲”猩猩相比对，发现Y染色体与猩猩的差异度为30%，而人类其它基因与猩猩的差异度为28%，这也就是说人类的Y染色体与人类其它基因相比存在2个百分点的进化程度差异。而这一进化过程是从大约600万年前开始的。

研究报告的撰写者、剑桥大学怀特黑德研究所主任戴维·佩奇和麻省理工学院的一名教授表示：“看起来Y染色体是人类染色体中进化最快的一个，它几乎就是一个不断变化的基因，就像是一座不断重建的房屋一样。”

并不意味着男人高级

怀特黑德研究所的詹妮弗·休斯说，研究人员对人类和猩猩的Y染色体进行了详细的比对，发现染色体的整个切片存在巨大的不同，人类的Y染色体存在着完整的基因，但猩猩的Y染色体上却没有。

当然，男人们也不要对这个消息太得意。休斯提醒说，决定人类性别的Y染色体进化的速度虽然很快，但这并不意味着男人本身就进化得更为高级。不过科学家表示，即便如此，我们还是可以肯定地说，Y染色体就是人类染色体进化速度的冠军。（来源：信息时报 信莲 梁杉）


Nature advance online publication 13 January 2010 | doi:10.1038/nature08700; Received 3 August 2009; Accepted 24 November 2009; Published online 13 January 2010

Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content
Jennifer F. Hughes1, Helen Skaletsky1, Tatyana Pyntikova1, Tina A. Graves2, Saskia K. M. van Daalen3, Patrick J. Minx2, Robert S. Fulton2, Sean D. McGrath2, Devin P. Locke2, Cynthia Friedman4, Barbara J. Trask4, Elaine R. Mardis2, Wesley C. Warren2, Sjoerd Repping3, Steve Rozen1, Richard K. Wilson2 & David C. Page1

1.Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
2.The Genome Center, Washington University School of Medicine, 4444 Forest Park Boulevard, St Louis, Missouri 63108, USA
3.Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam 1105 AZ, The Netherlands
4.Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North C3-168, Seattle, Washington 98109, USA
Correspondence to: David C. Page1 Correspondence and requests for materials should be addressed to D.C.P. (Email: dcpage@wi.mit.edu).


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The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome1, 2. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis3, 4. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes5, 6, 7, 8, but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, achieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically in sequence structure and gene content, indicating rapid evolution during the past 6 million years. The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. Although genetic decay may be the principal dynamic in the evolution of newly emergent Y chromosomes, wholesale renovation is the paramount theme in the continuing evolution of chimpanzee, human and perhaps other older MSYs.