Ellis N A, Goodfellow P J, Pym B, Smith M, Palmer M, Frischauf A M, Goodfellow P N
Imperial Cancer Research Fund, London, UK.
Nature. 1989 Jan 5;337(6202):81-4. doi: 10.1038/337081a0.
The Y chromosome, which in man determines the male sex, is composed of two functionally distinct regions. The pseudoautosomal region is shared between the X and Y chromosome and is probably required for the correct segregation of the sex chromosomes during male meiosis. The second region includes the sex-determining gene(s), the presence of which is necessary for the development of testes. The two regions have contrasting genetic properties: the pseudoautosomal region recombines between the X and Y chromosome; the Y-specific region must avoid recombination otherwise the chromosomal basis of sex-determination breaks down. The pseudoautosomal region is bounded at the distal end by the telomere and at the proximal end by X- and Y-specific DNA. We have found that the proximal boundary was formed by the insertion of an Alu sequence on the Y chromosome early in the primate lineage. Proximal to the Alu insertion there is a small region where similarity between the X and Y chromosomes is reduced and which is no longer subject to recombination.
Y染色体在人类中决定男性性别，它由两个功能不同的区域组成。假常染色体区域在X和Y染色体之间共享，可能是男性减数分裂过程中性染色体正确分离所必需的。第二个区域包括性别决定基因，其存在是睾丸发育所必需的。这两个区域具有相反的遗传特性：假常染色体区域在X和Y染色体之间发生重组；Y特异性区域必须避免重组，否则性别决定的染色体基础就会瓦解。假常染色体区域在远端由端粒界定，在近端由X和Y特异性DNA界定。我们发现，近端边界是由灵长类谱系早期Y染色体上Alu序列的插入形成的。在Alu插入的近端有一个小区域，X和Y染色体之间的相似性降低，且不再发生重组。
