National Museum of Marine Biology and Aquarium, Pingtung, 944, Taiwan.
Fish Physiol Biochem. 2005 Apr;31(2-3):111-5. doi: 10.1007/s10695-006-7591-1.
Most broadcast spawning scleractinian corals synchronously release gametes during a brief annual spawning period. In southern Taiwan, the mass spawning of scleractinians occurs in lunar mid-March. Endocrine system has been proposed to play important roles in this annual phenomenon. A scleractinian coral, Euphyllia ancora has been selected as a model for the hormones and reproduction studies. We detected the presence of estradiol (E2), testosterone (T), glucuronided E2, glucuronided T, aromatase, immunoreactive (ir)GnRH in coral polyps E. ancora. Annual profiles of sex steroids, aromatase, and irGnRH have also been characterized. We found the parallel increases in irGnRH concentrations, aromatase activity and free E2 and glucuronided E2 concentrations at the time of coral mass spawning. The stimulation of mammalian (m)GnRH agonist in the increased aromatase activity and sex steroid concentrations was also observed in corals. Coral extracts (irGnRH) and mGnRH agonist had a similar dose-dependent effect on luteinizing hormone release in black porgy fish pituitary cells (in vitro). In conclusion, our data suggest that irGnRH and glucuronided E2 may play important roles in the control of reproduction and mass spawning in corals. Corals already evolved the vertebrate-type hormone system in the sexual reproduction.
大多数有性繁殖的造礁石珊瑚在短暂的年度繁殖期内同步释放配子。在台湾南部，石珊瑚的大规模繁殖发生在农历三月中旬。内分泌系统被认为在这种年度现象中起着重要作用。一种石珊瑚，(Euphyllia ancora)已被选为激素和生殖研究的模型。我们检测到石珊瑚(E. ancora)的珊瑚虫中存在雌二醇(E2)、睾丸激素(T)、葡萄糖醛酸雌二醇、葡萄糖醛酸睾酮、芳香酶和免疫反应性(GnRH)。还描述了性类固醇、芳香酶和 irGnRH 的年度特征。我们发现，在珊瑚大规模繁殖时，irGnRH 浓度、芳香酶活性和游离 E2 和葡萄糖醛酸 E2 浓度呈平行增加。在珊瑚中也观察到哺乳动物(m)GnRH 激动剂刺激芳香酶活性和性类固醇浓度的增加。珊瑚提取物(irGnRH)和 mGnRH 激动剂对黑鲷鱼脑垂体细胞中促黄体生成素释放具有相似的剂量依赖性效应(体外)。总之，我们的数据表明，irGnRH 和葡萄糖醛酸雌二醇可能在珊瑚的生殖和大规模繁殖控制中发挥重要作用。珊瑚已经在有性生殖中进化出了脊椎动物类型的激素系统。
