Mastrangelo P, Zwingman T, Erickson R P, Blecher S R
Department of Molecular Biology and Genetics, University of Guelph, Ontario, Canada.
Dev Genet. 1994;15(2):129-38. doi: 10.1002/dvg.1020150203.
The presence of the mutation Sex reversed (Sxr), a copy of a Y-chromosomal segment that gets transferred to an X chromosome, causes the resulting XXSxr mice to develop as apparent males. However, several features of male sexual development are abnormal in these animals. The testes are small and aspermatogenic, and the epididymides lack the initial segment. Testes and epididymides show abnormalities of extracellular matrix. In this study we examined transcription of the conserved Y chromosomal gene Zfy, which has an X-chromosomal homologue (Zfx). Northern blotting showed Zfy to be expressed in the testes of XXSxr animals, except for those that carry the coat-marker gene Tabby (Ta), despite the lack of germ cells in XXSxr mice. Reverse transcription polymerase chain reaction (RT-PCR) studies detected Zfy in mRNA in testes even when Ta was present. RT-PCR also demonstrated Zfy transcription in epididymides of normal males, though not in XXSxr mice. Previous authors reported an absence of Zfy transcription in XXSxr testes; Zfy transcription in normal testes has been ascribed to germ cells. Our observation indicates that this idea requires re-evaluation. The occurrence of Zfy transcription in the normal epididymis is similarly a novel finding that may help explain those aspects of epididymal development that occur in the absence of androgen.
性反转（Sxr）突变的存在，即一段Y染色体片段转移到X染色体上，导致产生的XXSxr小鼠发育为明显的雄性。然而，这些动物的雄性性发育有几个特征是异常的。睾丸小且无精子生成，附睾缺乏起始段。睾丸和附睾显示细胞外基质异常。在本研究中，我们检测了保守的Y染色体基因Zfy的转录情况，该基因有一个X染色体同源物（Zfx）。Northern印迹分析显示，Zfy在XXSxr动物的睾丸中表达，携带毛色标记基因虎斑（Ta）的动物除外，尽管XXSxr小鼠缺乏生殖细胞。逆转录聚合酶链反应（RT-PCR）研究即使在存在Ta的情况下也在睾丸mRNA中检测到了Zfy。RT-PCR还证明正常雄性附睾中有Zfy转录，但XXSxr小鼠中没有。先前的作者报道XXSxr睾丸中不存在Zfy转录；正常睾丸中的Zfy转录归因于生殖细胞。我们的观察表明这一观点需要重新评估。正常附睾中Zfy转录的出现同样是一个新发现，可能有助于解释在没有雄激素的情况下附睾发育的那些方面。
