Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials
Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials
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与 ZFY（一种候选人类性别决定基因）同源的序列在有袋动物中是常染色体
作者：
A. Sinclair;J. W. Foster;J. Spencer;D. Page;M. Palmer;P. Goodfellow;J. Graves
胎盘哺乳动物的性别分化是由Y染色体编码的决定睾丸的基因作用的结果。该基因导致冷漠的性腺发育为睾丸，从而启动激素级联反应，产生男性表型1，2。最近，睾丸决定基因的候选基因(ZFY，Y-锌指蛋白)已被克隆3，4。ZFY探针在一系列真核哺乳动物的DNA中检测到男性特有的(Y-连锁)序列，以及映射到人类X染色体3的X-连锁序列(ZFX)。在有袋类动物中，Y染色体似乎也决定了性腺的命运，但并不是所有的性二型都是如此。使用ZFY探针，令人惊讶的是，我们发现ZFY同源序列既不在有袋类动物的X染色体上，也不在Y染色体上，而是映射到自体染色体上。这表明ZFY不是有袋类动物的主要性别决定基因。要么是有袋类和真兽类性别决定的遗传途径不同，要么是它们是相同的，ZFY不是人类性别决定的主要信号。
Sexual differentiation in placental mammals results from the action of a testis-determining gene encoded by the Y chromosome. This gene causes the indifferent gonad to develop as a testis, thereby initiating a hormonal cascade which produces a male phenotype1,2. Recently, a candidate for the testis-determining gene (ZFY, Y-borne zinc-finger protein) has been cloned3,4. The ZFY probe detects a male-specific (Y-linked) sequence in DNA from a range of eutherian mammals, as well as an X-linked sequence (ZFX) which maps to the human X chromosome3. In marsupials it is also the Y chromosome that seems to determine the fate of the gonad, but not all sexual dimorphisms5. Using the ZFY probe we find, surprisingly, that the ZFY homologous sequences are not on either the X or the Y chromosome in marsupials, but map to the auto-somes. This implies ZFY is not the primary sex-determining gene in marsupials. Either the genetic pathways of sex determination in marsupials and eutherians differ, or they are identical and ZFY is not the primary signal in human sex determination.