BBC新闻 - 质疑男性Y染色体灭绝理论

BBC新闻 - 质疑男性Y染色体灭绝理论 译者： zhangn1987@gmail.com 发表时间：2012-02-23浏览量：1308评论数：0挑错数：0 根据对比人类和猕猴染色体的最新研究，男性Y染色体的基因衰变几乎完全结束。 Male Y chromosome extinction theory challenged By Neil Bowdler Science and health reporter, BBC News 质疑男性Y染色体灭绝理论科技和健康记者尼尔.柏德乐（Neil Bowdler），BBC新闻 Human cells carry 23 pairs of chromosomes, including one pair which determine gender 人类细胞携带了23对染色体，其中包括了一对确定性别的染色体 Men may not become extinct after all, according to a new study. 根据最新的研究，男性并不会最终灭绝。 Previous research has suggested the Y sex chromosome, which only men carry, is decaying genetically so fast that it will be extinct in five million years' time. 以往的研究显示了，男性所独有的Y染色体在遗传基因中正快速的衰变，其在未来50万年内就会灭绝。 A gene within the chromosome is the switch which leads to testes development and the secretion of male hormones. 染色体中的基因是致使睾丸发育和男性荷尔蒙分泌的关键。 But a new US study in Nature suggests the genetic decay has all but ended. 但是一项发表在自然杂志中的美国最新研究表明，遗传衰变几乎完全结束。 Professor Jennifer Graves of Australian National University has previously suggested the Y chromosome may become extinct in as little as five million years' time, based on the rate at which genes are disappearing from the chromosome. 澳大利亚国立大学的詹妮弗.格雷夫斯（Jennifer Graves）教授，在之前曾表示根据基因在染色体中消失的速度，Y染色体可能经过至少500万年的时间灭绝。 Genetics professor Brian Sykes predicted the demise of the Y chromosome, and of men, in as little as 100,000 years in his 2003 book Adam's Curse: A Future without Men. 遗传学教授布莱恩.塞克斯（Brian Sykes）曾在他2003年出版的“亚当的诅咒：没有男性的未来”一书中预言道，Y染色体的死亡，亦即男性的灭亡，会经过至少10万年。 The predictions were based on comparisons between the human X and Y sex chromosomes. While these chromosomes were once thought to be identical far back in the early history of mammals, the Y chromosome now has about 78 genes, compared with about 800 in the X chromosome. 这个预言是建立在对人类X和Y性别染色体的对比之上。这些染色体曾经一度被认为在哺乳动物早起时期是相同的，然而Y染色体现在拥有78个基因，X染色体拥有约800个基因。 “Start Quote “ 引用 The Y is not going anywhere and gene loss has probably come to a halt” End Quote Dr Jennifer Hughes Whitehead Institute, Cambridge, Massachusetts Y染色体不会消失，基因遗失也几乎停止” 引用于马萨诸塞州剑桥大学怀特黑德研究所（Whitehead Institute）的詹妮弗.休斯（Jennifer Hughes）博士。 Jennifer Hughes and colleagues at the Whitehead Institute in Cambridge, Massachusetts, have sought to determine whether rumours of the Y chromosome's demise have been exaggerated. 詹妮弗.休斯和她在马萨诸塞州剑桥大学怀特黑德的同事们，一直在试图确定关于Y染色体死亡的说法是否被夸大了。 In a previous Nature paper in 2005, they compared the human Y chromosome with that of the chimpanzee, whose lineage diverged from that of humans about six million years ago. 在之前2005年发表的自然杂志中，他们对比了人类与其在600万年前脱离血统的黑猩猩的Y染色体。 They have now sequenced the Y chromosome of the rhesus monkey, which is separated from humans by 25 million years of evolution. 他们现在已经测序了在2500万年前与人类在进化史中分离的猕猴的Y染色体。 The conclusion from these comparative studies is that genetic decay has in recent history been minimal, with the human chromosome having lost no further genes in the last six million years, and only one in the last 25 million years. 从对比研究中得出的结论是，在近代历史中遗传衰变微乎其微，在600万年前，人类的染色体已经没有进一步的遗失了，在过去2500万年间仅有一个。 "The Y is not going anywhere and gene loss has probably come to a halt," Ms Hughes told BBC News. "We can't rule out the possibility it could happen another time, but the genes which are left on the Y are here to stay. “Y染色体不会消失，基因遗失也几乎停止，” 休斯女士告诉BBC新闻。“我们并不能将它发生在另一个时期的可能性完全排除在外，但是基因将永远存在于Y染色体上不会离开。” "They apparently serve some critical function which we don't know much about yet, but the genes are being preserved pretty well by natural selection." X-Y crossing “很显然，他们用了一些我们并不了解的判定函数，但是基因正被自然选择保存的相当完好。” X - Y 基因交换 Most humans cells contain 23 sets of chromosomes, including one pair of sex chromosomes. In women, this sex pair consist of two X chromosomes, while men have one X and one Y chromosome. It is a gene within the Y chromosome which triggers the development in the embryo of male testes and the secretion of male hormones. 绝大部分的人类细胞含有23对染色体，其中包括一对性别染色体。 对女性而言，性别染色体是一对X染色体，男性则有一个X染色体和一个Y染色体。 在Y染色体中的基因促使了男性睾丸在胚胎时期的发育和男性荷尔蒙的分泌。 Advertisement 公告 Professor Julian Parkhill visits the Wellcome Collection to unravel the science behind the genome 朱利安.帕克希尔（Julian Parkhill）教授访问了惠康收藏（Wellcome Collection）揭示了基因组背后的科学。 Genetic deterioration of the Y chromosome has occurred because unlike with the two X chromosomes in women, there is very little swapping of genetic material between the Y and X chromosome during reproduction. This means mutations and deletions in the Y chromosome are preserved between (male) generations. 在基因复制阶段，不同于女性拥有两个X染色体，X和Y染色体之间只有非差少的遗传物质互换，Y染色体的基因退化已经发生了。这意味着在（男性）的一代人中，存在着Y染色体的基因突变和缺失。 "The X is fine because in females it gets to recombine with the other X but the Y never gets to recombine over almost its entire length, and shutting down that recombination has left the Y vulnerable to all these degenerative forces," said Dr Hughes, "which is why we're left with the Y we have today." “由于在女性中，X染色体会于另一个X染色体重组，而不会于Y染色体在它（Y染色体）完整的长度上重组，并且X染色体会自主的离开Y染色体从而停止重组并退化，因此X染色体得以保存完好，”休斯博士说到，“这就是我们离开Y染色体成为女性的原因。” Commenting on the paper, Professor Mark Pagel, an evolutionary biologist at the University of Reading and author of Wired for Culture: Origins of the Human Social Mind, said that while there might be some squabbling in academic circles over the timings of the events, the paper told us there was a future for males in the very long term. 雷丁大学进化生物学家、有线文化：人类社会意识起源的作者马克.佩洁尔（Mark Pagel），对文章上评论到，在学术圈中会有一些在事件时间上的争论，这篇文章告诉我们男性在很长一段时间内曾是被认为有特定未来的。 "It's a very nice piece of work, showing that gene loss in the male-specific region of the Y chromosome proceeds rapidly at first - exponentially in fact - but then reaches a point at which purifying selection brings this process to a halt." ”这是一项很好的工作，展示了在Y染色体这个男性特有领域，基因遗失进程以一种迅猛的开始，以指数的形式，然后到达了一个由纯粹自然选择而决定的进程终止点。”