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2015年4月20日 讯 /生物谷BIOON/ –近日，来自昆士兰大学的研究者使得哺乳动物的一种“退休”的性基因重新复活过来，使其开启雄性小鼠的发育；这种名为Dmrt1的基因虽然不会被哺乳动物用来确定性别，但其却在决定许多脊椎动物的性别上扮演着重要的角色，比如青蛙、鱼类及鸟类等；相关研究为揭开决定人类和动物性别的基因的进化提供了新的研究线索和思路。
研究者Peter说道，Dmrt1是一种古老的遗传遗迹，科学家们认为该基因在哺乳动物的性别决定中失去了应有的功能，而如今现代哺乳动物的性别则是由Y染色体上基因变体来确定的。当功能性基因被替换角色后，比如Dmrt1被Y染色体上的性别决定区所替代，我们就可以假设这是因为原始的基因失去了自身的功能或者其并不在合适的时间及地点被表达所致。
当这一切发生时，我们机体就会阻断维护这些基因的功能，最终这种失去功能的基因就会退休，或者其有可能获取新的功能；从理论上来讲Dmrt1基因你就好比是一台古老的、没有维护的割草机放在小屋落满灰尘一样，然而让研究者比较惊奇的是，当将割草机（Dmrt1）推出小屋其就会重新获得完整的功能，这一点让人非常不可思议。
文章中研究者Liang Zhao表示，我们通过过表达基因Dmrt1就可以实现雌性向雄性的完全成功逆转；目前在哺乳动物中被认为有一些基因可以决定性别，而如今我们也可以将Dmrt1基因加入到这个性别决定的重要群组中。从进化学角度来讲，新基因接替老基因后，老基因就会退休但是当其处于合适的时间及位置时候其仍然会履行自己之前的功能或角色。
研究者希望本文研究可以帮助科学家们在农业、害虫等研究领域带来帮助，比如管理害虫的性别比率等，相关研究刊登于国际杂志Development上，由澳大利亚研究委员会等机构提供资助。（基因宝jiyinbao.com）
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Female-to-male sex reversal in mice caused by transgenic overexpression of Dmrt1.
Zhao L1, Svingen T1, Ng ET1, Koopman P2.
Genes related to Dmrt1, which encodes a DNA-binding DM domain transcription factor, act as triggers for primary sex determination in a broad range of metazoan species. However, this role is fulfilled in mammals by Sry, a newly evolved gene on the Y chromosome, such that Dmrt1 has become dispensable for primary sex determination and instead maintains Sertoli cell phenotype in postnatal testes. Here, we report that enforced expression of Dmrt1 in XX mouse fetal gonads using a Wt1-BAC transgene system is sufficient to drive testicular differentiation and male secondary sex development. XX transgenic fetal gonads showed typical testicular size and vasculature. Key ovarian markers, including Wnt4 and Foxl2, were repressed. Sertoli cells expressing the hallmark testis-determining gene Sox9 were formed, although they did not assemble into normal testis cords. Other bipotential lineages differentiated into testicular cell types, including steroidogenic fetal Leydig cells and non-meiotic germ cells. As a consequence, male internal and external reproductive organs developed postnatally, with an absence of female reproductive tissues. These results reveal that Dmrt1 has retained its ability to act as the primary testis-determining trigger in mammals, even though this function is no longer normally required. Thus, Dmrt1 provides a common thread in the evolution of sex determination mechanisms in metazoans.