Elevated expression of P450c17 (CYP17) during testicular formation in the frog
Elevated expression of P450c17 (CYP17) during testicular formation in the frog
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DOI：
10.1016/j.ygcen.2007.02.032
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发表时间：
2008-01-01
影响因子：
2.7
通讯作者：
Nakamura, Masahisa
中科院分区：
文献类型：
--
作者：
Iwade, Ryosuke;Maruo, Koichi;Nakamura, Masahisa
性类固醇在许多脊椎动物的性腺分化中起着决定性作用。某些两栖动物的性别可以通过性类固醇来改变，但性别逆转的机制在很大程度上尚不清楚。在这项研究中，我们从青蛙中克隆并鉴定了 3 个编码性类固醇合成酶的 cDNA，即 CYP11A1、CYP17 和 3 beta-HSD。 RT-PCR分析表明，在R.rugosa的性别决定过程中，雄性性腺中CYP17的表达量远高于雌性性腺，而CYP11A1和3β-HSD未表现出两性二态性表达。当将睾酮注射到蝌蚪中进行雌雄逆转时，注射睾酮后第 16 天和 24 天，性腺中 CYP17 的表达似乎非常强。 CYP11A1在第16天转录也较高，但与CYP17相比表达较弱。3β-HSD的表达在性逆转过程中没有变化。此外，原位杂交分析显示，CYP17在雄性性腺和睾丸的体细胞中表达。注射睾酮后第 16 天和第 24 天，雌性向男性性别逆转的性腺（睾丸）的体细胞中也产生了 CYP17 的阳性信号，但在卵巢中则没有。综上所述，结果表明 CYP17 与 R. rugosa 性腺的睾丸分化密切相关。 (C) 2007 年，爱思唯尔公司出版。
Sex steroids play decisive roles in gonadal differentiation in many species of vertebrates. The sex can be changed by sex steroids in some species of amphibians, but the mechanism of the sex-reversal is largely unknown. In this study, we cloned and characterized 3 cDNAs encoding sex steroid-synthesizing enzymes, i.e., CYP11A1, CYP17 and 3 beta-HSD from the frog Rana rugosa. RT-PCR analysis showed that the CYP17 expression was much higher in male gonads than in female ones during sex determination in R. rugosa, whereas CYP11A1 and 3 beta-HSD showed no sexually dimorphic expression. When testosterone was injected into tadpoles for female-to-male sex reversal, CYP17 expression appeared to be very strong in the gonad at days 16 and 24 after injection of testosterone. CYP11A1 was also transcribed higher at day 16, but its expression was weaker when compared with that of CYP17 The expression of 3 beta-HSD did not change during the sex reversal. In addition, in situ hybridization analysis revealed that CYP17 was expressed in somatic cells of the indifferent male gonad and in those of the testis. Positive signals of CYP17 were also produced in somatic cells of a female-to-male sex-reversed gonad (testis) at days 16 and 24 post testosterone injection, but not in the ovary. Taken together, the results suggest that CYP17 is very involved in testicular differentiation of the gonad in R. rugosa. (C) 2007 Published by Elsevier Inc.