The Question of Functional Homology of Hatschek's Pit of Amphioxus (Branchiostoma belcheri) and the Vertebrate Adenohypophysis(Endocrinology)
The Question of Functional Homology of Hatschek's Pit of Amphioxus (Branchiostoma belcheri) and the Vertebrate Adenohypophysis(Endocrinology)
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DOI：
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发表时间：
1992-04
影响因子：
0.9
通讯作者：
M. Nozaki;A. Gorbman
中科院分区：
文献类型：
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作者：
M. Nozaki;A. Gorbman
用抗人促黄体激素β亚基(hLH-β)和人绒毛膜促性腺激素的抗体，对文昌鱼哈氏窝的促性腺激素活性进行了免疫细胞化学研究。这证实了C.Y.Chang等人的说法。类似脊椎动物的促性腺激素[1，2]在这个结构中，口腔背部有一条开放的凹槽。如果这一证据从表面上被接受，就可以从原脊索动物哈茨海沟(头脊椎动物)或神经腺(海鞘动物)构建脊椎动物腺垂体的进化模式。这两个结构都对口腔内的水流开放。因此，它们可能能够采集热、化学或信息素季节性循环的线索，并通过促性腺激素刺激，使生殖活动与这些季节性线索同步。对早期脊椎动物的腺垂体是化学感受器这一观点的额外支持来自于这样一个事实，即在环口和弹性支链中，它是作为同一上皮层的一部分发育的，并且直接与嗅器官相邻。从原脊索动物到脊椎动物类型的生殖控制的进展包括最终使用感觉器官和神经系统来采样环境变化，以及将腺垂体功能与中枢神经控制联系起来。然后，可以将腺泡灌洗液与口腔隔绝，并与环境直接接触。
Using antibodies to the beta subunit of human luteinizing hormone (hLHβ) and human chorionic gonadotropin, immunocytochemical evidence was obtained for gonadotropin activity in Hatschek's pit of amphioxus, Branchiostoma belcheri. This confirms the claim by C. Y. Chang et at. [1, 2] of vertebrate-like gonadotropin in this structure, an open groove in the dorsal part of the oral cavity. If this evidence is accepted at face value, a scenario can be constructed for the evolutionary pattern of the vertebrate adenohypophysis from the protochordate Hatschek's pit (cephalochordates) or neural gland (ascidians). Both of these structures are open to water currents in the mouth cavity. Thus, they may be able to sample thermal, chemical or pheromonal seasonally cycling clues and by gonadotropic stimulation, synchronize reproductive activity with such seasonal clues. Additional support for the idea that the early vertebrate adenohypophysis was a chemoreceptive organ comes from the fact that in cyclostomes and elasmobranchs it develops as part of the same epithelial layer and is directly contiguous with the olfactory organ. Advancement from the protochordate to vertebrate type of reproductive control involves the eventual use of sense organs and the nervous system to sample environmental changes, and the linkage of adenohypophysial function to central nervous control. The adenohypoph ysis then can be closed off from the mouth and direct environmental contact.