Dorit R L, Akashi H, Gilbert W
Department of Biology, Yale University, New Haven, CT 06511, USA.
Science. 1995 May 26;268(5214):1183-5. doi: 10.1126/science.7761836.
DNA polymorphism in the Y chromosome, examined at a 729-base pair intron located immediately upstream of the ZFY zinc-finger exon, revealed no sequence variation in a worldwide sample of 38 human males. This finding cannot be explained by global constraint on the intron sequence, because interspecific comparisons with other nonhuman primates revealed phylogenetically informative sequence changes. The invariance likely results from either a recent selective sweep, a recent origin for modern Homo sapiens, recurrent male population bottlenecks, or historically small effective male population sizes. A coalescence model predicts an expected time to a most recent common ancestral male lineage of 270,000 years (95 percent confidence limits: 0 to 800,000 years).
对位于ZFY锌指外显子上游紧邻的一段729个碱基对的内含子进行检测，结果显示，在来自世界各地的38名男性样本中，Y染色体上不存在DNA多态性。这一发现无法用内含子序列的整体限制来解释，因为与其他非人类灵长类动物的种间比较显示出了具有系统发育信息的序列变化。这种不变性可能是由近期的选择性清除、现代智人的近期起源、反复出现的男性群体瓶颈，或历史上较小的有效男性群体规模导致的。一个合并模型预测，最近共同祖先男性谱系的预期时间为27万年（95%置信区间：0至80万年）。
