Progestin is important for testicular development of male turbot (Scophthalmus maximus) during the annual reproductive cycle through functionally distinct progestin receptors
Progestin is important for testicular development of male turbot (Scophthalmus maximus) during the annual reproductive cycle through functionally distinct progestin receptors
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孕激素通过功能不同的孕激素受体，对于雄性大菱鲆（大菱鲆）在年度生殖周期中的睾丸发育非常重要
DOI：
10.1007/s10695-017-0411-y
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发表时间：
2018-02-01
影响因子：
2.9
通讯作者：
Li, Jun
中科院分区：
文献类型：
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作者：
Feng, Chengcheng;Xu, Shihong;Li, Jun
在硬骨鱼类中，性类固醇激素对繁殖至关重要。众所周知，孕激素可以促进精子形成。为了进一步了解大菱鲆（Scophthalmus maximus）雄体生殖周期中睾丸激素受体的作用，本研究观察了大菱鲆雄体的睾丸发育，定量测定了几种性类固醇激素，检测了睾丸激素受体的表达，并测定了精子的各项参数。结果表明，大菱鲆精巢结构为小叶型。在繁殖季节，一些精母细胞（阶段III）发育成精子细胞（阶段IV），然后在精子发生过程中分化成精子（阶段V），最后退化为精母细胞（阶段VI）。随着睾丸的发育，血清孕酮（P4）和17α，20 β-二羟基-4-异戊烯-3-酮（DHP）水平从IV期到V期明显升高。此外，与精子活力较低的鱼相比，精子活力较高的雄性显示出较高的P4和DHP水平。这些结果表明，P4和DHP可能因季节变化而诱导精子发生。同时，在睾丸中，核孕酮受体（pgr）在整个生殖周期中表达，其水平在精子发生期间达到峰值，而膜孕酮受体α（mPRα）的表达没有显著变化。然而，在精子中，mPRα的表达高于睾丸，并与曲线运动速度（VCL）、精子活力和运动持续时间呈显著正相关。因此，在精子发生过程中，mPR α蛋白的表达水平可能是影响精子活力的重要因素。
In teleost, sex steroid hormones are critical for reproduction. Progestin is known to promote spermiation. To further understand the functions of progestin via its receptors during the annual reproductive cycle in male turbot (Scophthalmus maximus), we observed testicular development, quantified several sex steroid hormones, detected the expression of progestin receptors, and measured various sperm parameters. Results showed that the turbot testicular structure was of the lobular type. During breeding season, a number of spermatocytes (stage III) developed into spermatids (stage IV), then differentiated into sperm during spermiogenesis (stage V), and finally regressed to spermatocytes (stage VI). Concomitant with testicular development, serum progesterone (P4) and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) exhibited higher levels from stage IV to V than other stages. Furthermore, males with higher motility sperm showed higher levels of P4 and DHP compared with fish with lower motility sperm. These results indicated that P4 and DHP might induce spermatogenesis due to seasonal changes. Concurrently, in testes, the nuclear progesterone receptor (pgr) was expressed throughout the reproductive cycle and its level peaked during spermiogenesis while expression of membrane progestin receptor alpha (mPRα) did not change significantly. However, in sperm,mPRαexpression was higher than in testes and had a significant positive correlation with curvilinear velocities (VCL), sperm motility, and motility duration. In conclusion, progestin appears to exert a directpgr-mediated effect on spermiogenesis and improve sperm motility characteristics depending on the abundance ofmPRαprotein in sperm during spermiation.