Regulation of the type-II gonadotrophin alpha and beta subunit mRNAs by oestradiol and testosterone in the European eel.
Regulation of the type-II gonadotrophin alpha and beta subunit mRNAs by oestradiol and testosterone in the European eel.
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欧洲鳗鱼中雌二醇和睾酮对 II 型促性腺激素 α 和 β 亚基 mRNA 的调节。
DOI：
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发表时间：
1991
影响因子：
3.5
通讯作者：
Y. Fontaine
中科院分区：
文献类型：
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作者：
B. Quérat;A. Hardy;Y. Fontaine
欧洲鳗鲡 (Anguilla anguilla L.) 在白银阶段的促性腺功能非常弱：促性腺激素释放激素 (GnRH) 分泌不足，而且多巴胺抑制作用压倒了 GnRH 作用。在白银阶段，雌二醇刺激 II 型促性腺激素 (GTH-II) 的生物合成。为了进一步研究这种激活的分子机制，我们检查了睾酮和雌二醇给药对编码 GTH-II α 和 β 亚基的 mRNA 垂体水平的影响。使用相应的鳗鱼cDNA探针和Northern印迹分析。两周后，睾酮和雌二醇植入导致编码 GTH-II β 亚基的 mRNA 大幅增加（分别为 7 倍和 25 倍），并且 a 亚基 mRNA 水平略有但不显着的增加（分别为 1.8 倍和 1.5 倍）。这两种类固醇的共同植入表明它们对 β 亚基的作用增强（104 倍），而对 α mRNA 水平则显示出累加作用（2.9 倍）。效果在 4 天内即可检测到，并且在植入后 4 周达到最大。这些结果表明，在银阶段的欧洲鳗鱼中，性腺类固醇在翻译前水平上差异性地刺激GTH-II亚基基因的表达。
The gonadotrophic function of the European eel (Anguilla anguilla L.) at the silver stage is very weak: gonadotrophin-releasing hormone (GnRH) secretion is deficient and, moreover, dopamine inhibition overrides GnRH action. At the silver stage, oestradiol stimulates the biosynthesis of the type-II gonadotrophin (GTH-II). To study the molecular mechanism of this activation further, we examined the effect of testosterone and oestradiol administration on pituitary levels of mRNA encoding GTH-II alpha and beta subunits. Corresponding eel cDNA probes and Northern blot analysis were used. After 2 weeks, testosterone and oestradiol implantation resulted in a strong increase in mRNA encoding the GTH-II beta subunit (7-fold and 25-fold, respectively) and in a slight, but non-significant, rise in the a subunit mRNA level (1.8-fold and 1.5-fold, respectively). Co-implantation of these two steroids suggested a potentiation of their effects on the beta subunit (104-fold) while an additive effect was indicated on the alpha mRNA level (2.9-fold). Effects were detectable within 4 days and were maximal 4 weeks after implantation. These results indicate that in the European eel at the silver stage, gonadal steroids stimulate differentially the expression of GTH-II subunit genes at a pretranslational level.