Four evolutionary strata on the human X chromosome
Four evolutionary strata on the human X chromosome
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DOI：
10.1126/science.286.5441.964
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发表时间：
1999-10-29
期刊：
影响因子：
56.9
通讯作者：
Page, DC
中科院分区：
文献类型：
--
作者：
Lahn, BT;Page, DC
人类的性染色体是从常染色体进化而来的。19个祖先常染色体基因作为X和Y染色体上的分化同源物持续存在。个体X-Y基因对的年龄（用核苷酸分歧测量）和它们的X成员在X染色体上的位置被发现是高度相关的。在至少四个“进化层”中，年龄从长臂远端到短臂远端呈阶梯状递减。“人类性染色体的进化可能被至少四个事件打断，每个事件都抑制了一个层中的X-Y重组，而不干扰X染色体上的基因顺序。第一个事件，标志着X-Y分化的开始，发生在大约2.4亿至3.2亿年前，在哺乳动物和鸟类谱系分化之后不久。
Human sex chromosomes evolved from autosomes. Nineteen ancestral autosomal genes persist as differentiated homologs on the X and Y chromosomes. The ages of individual X-Y gene pairs (measured by nucleotide divergence) and the Locations of their X members on the X chromosome were found to be highly correlated. Age decreased in stepwise fashion from the distal long arm to the distal short arm in at least four "evolutionary strata." Human sex chromosome evolution was probably punctuated by at Least four events, each suppressing X-Y recombination in one stratum, without disturbing gene order on the X chromosome. The first event, which marked the beginnings of X-Y differentiation, occurred about 240 to 320 million years ago, shortly after divergence of the mammalian and avian lineages.