Mammalian ZFY sequences exist in reptiles regardless of sex-determining mechanism.
Mammalian ZFY sequences exist in reptiles regardless of sex-determining mechanism.
复制标题
无论性别决定机制如何，哺乳动物的 ZFY 序列都存在于爬行动物中。
作者：
J. Bull;D. Hillis;S. O’Steen
在一些爬行动物中，卵孵化温度决定胚胎是以雄性还是雌性的身份孵化；在另一些爬行动物中，性染色体决定性别。克隆的哺乳动物睾丸决定因子基因(ZFY)与具有性染色体的爬行动物的基因组DNA和具有温度依赖性性别决定的爬行动物的DNA杂交。未观察到杂交模式的性别差异。ZFY与多腺化RNA的杂交表明，在温度敏感期，该基因的爬行动物版本在两性胚胎中都有表达。如果这些高度保守的序列在爬行动物性别决定中很重要，那么依赖温度和基因类型的性别决定可能有类似的分子基础。对于具有XX/XY或ZZ/ZW系统的爬行动物来说，杂交模式中没有性别差异引发了ZFY序列是否位于它们的性染色体上的问题。
In some reptiles, egg incubation temperature determines whether the embryo hatches as male or female; in others, sex chromosomes determine sex. A cloned gene (ZFY) representing the putative testis-determining factor in mammals was hybridized to genomic DNA of reptiles with sex chromosomes and to DNA of reptiles with temperature-dependent sex determination. No sex differences in hybridization patterns were observed. Hybridization of ZFY to polyadenylated RNA indicates that reptilian versions of this gene are expressed in embryos of both sexes during the temperature-sensitive period. If these highly conserved sequences are important in reptilian sex determination, then temperature-dependent and genotypic sex determination may have a similar molecular basis. For reptiles with XX/XY or ZZ/ZW systems, the absence of sex differences in hybridization patterns raises the question of whether the ZFY sequences reside on their sex chromosomes.