Studies on chorionic gonadotropins in dolphins

鲸类动物胎盘的功能尚不清楚。一些鲸目动物，如海豚，有很长的妊娠期，几乎与人类相当。在以往的研究中，我们证实了瓶鼻海豚胎盘中存在促黄体生成素（LH）样物质。在本研究中，我们获得了海豚胎盘也产生和分泌促卵泡激素（FSH）的证据。在和歌山县太地县采集了野生怀孕（早期、中期和晚期）宽吻海豚的胎盘和垂体。我们克隆了编码FSHbeta亚基的cdna。FSHbeta cDNA在胎盘各阶段均可检测到，但表达量远低于垂体。抗犬卵泡刺激素免疫组化观察显示，母体绒毛组织和胎儿绒毛组织均呈阳性染色，后者反应更强烈。

The function of placenta in cetaceans is still unclear. Some cetaceans, such as dolphins, have a long gestational period almost comparable with that of humans. In the previous study, we demonstrated that luteinizing hormone (LH) like substances exist in a bottle nose dolphin placenta. In the present study, we obtained the evidence that dolphin placenta also produces and secretes follicle stimulating hormone (FSH). Dolphin placentae and pituitaries were collected from wild pregnant (early, middle, and late stages) bottlenose dolphin captured in the traditional drive fisheries at Taiji, Wakayama prefecture. We cloned cDNAs encoding FSHbeta subunit. The FSHbeta cDNA could be detected in the placentae from all the stages, although the expression was much weaker than that in the pituitaries. Immunohistochemical observations employing anti-canine FSH revealed positive staining in both the maternal and fetal villositical tissues, showing much stronger reaction in the latter.