Progesterone Is a Sperm-Releasing Factor from the Sperm-Storage Tubules in Birds
Progesterone Is a Sperm-Releasing Factor from the Sperm-Storage Tubules in Birds
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DOI：
10.1210/en.2011-0237
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发表时间：
2011-10-01
期刊：
影响因子：
4.8
通讯作者：
Sasanami, Tomohiro
中科院分区：
文献类型：
--
作者：
Ito, Tomomi;Yoshizaki, Norio;Sasanami, Tomohiro
由于输卵管子宫阴道交界处（UVJ）中存在精子储存小管（SST），一旦射精的精子进入雌性生殖道，它们可以在家禽中存活很长时间，尽管精子在SST中的摄取、维持和控制释放的具体机制仍有待阐明。在本报告中，我们提供了黄体酮触发 UVJ 中 SST 释放常驻精子的证据。 SST的超微结构观察表明，驻留精子在产卵后20小时左右从SST中释放出来。当产蛋鸡注射黄体酮时，大部分精子在注射后 1 小时内从 SST 中释放出来。原位杂交分析证明 UVJ 中存在膜孕激素受体 α 转录本，并且通过蛋白质印迹法在 UVJ 提取物中检测到翻译的蛋白质。此外，SST上皮细胞中分泌颗粒的数量在排卵周期中会波动，孕酮给药模仿了这种现象。使用 [(3)H]-孕酮的结合测定表明，UVJ 膜部分中 [(3)H]-孕酮存在高亲和力、有限容量、可饱和且单一的结合位点，并且该受体不与合成的抗孕激素 RU486 相互作用。这些结果首次证明孕酮刺激驻留精子从 SST 中释放，并且精子的释放可能通过膜孕激素受体 α 介导的信号转导发生。 （内分泌学152：3952-3962，2011）
Because of the presence of sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) in the oviduct, once ejaculated sperm have entered the female reproductive tract, they can survive for a prolonged time in domestic birds, although the specific mechanisms involved in the sperm uptake into, maintenance within, and controlled release from the SST remain to be elucidated. In this report, we provide evidence that progesterone triggers the release of the resident sperm from the SST in the UVJ. The ultrastructural observation of the SST indicated that the resident sperm are released from the SST around 20 h after oviposition. When laying birds were injected with progesterone, most of the sperm were released from the SST within 1 h of injection. In situ hybridization analyses demonstrated the presence of the transcripts of membrane progestin receptor alpha in the UVJ, and the translated proteins were detected in the UVJ extracts by Western blotting. Moreover, the number of secretory granules in the SST epithelial cells fluctuates during the ovulatory cycle, and the progesterone administration mimics this phenomena. A binding assay using [(3)H]-progesterone indicated the presence of a high affinity, limited capacity, saturable and single binding site for [(3)H]-progesterone in the membrane fraction of the UVJ, and this receptor did not interact with the synthetic antiprogestin RU486. These results demonstrated for the first time that the progesterone stimulates the release of the resident sperm from the SST and that the release of the sperm might occur via membrane progestin receptor alpha-mediating signal transduction. (Endocrinology 152: 3952-3962, 2011)