Localization of circadian clock and its structure

昼夜节律是一种由时间测量机制（生物钟）支撑的大约24小时的内源性振荡。阐明这一机制的策略包括三个渐进阶段：(1)候选时钟组织的定位，(2)组织自振荡能力的证明，以及(3)从细胞或分子生物学的角度探索更深层次的机制。这个项目团队由12名活跃的研究人员组成，他们沿着这个策略工作。结果如下：1。后生动物时钟的定位：蟋蟀视叶的自振荡能力几乎得到了决定性的证明。在啮齿类动物身上尝试了视交叉上核的种间移植。在松果体和脊椎动物的眼睛中，对控制显性节律的关键因素褪黑素的产生进行了深入的研究。细胞水平的时钟：一项分子生物学研究表明，神经孢子虫节律的时钟突变以钙代谢异常为特征。利用计算机系统监测细胞运动，分析草履虫游动节律的生物物理机制。PTTH细胞可能是昆虫脑时钟的重要组成部分，我们试图用免疫组织化学方法来定位PTTH细胞。光周期时钟：也研究了光周期与昼夜节律的关系。在对蟋蟀的研究中得到了一个有趣的结果，重水延长了运动的自由奔跑期，但不影响临界光周期。现在被广泛接受的外部符合模型可能不适用于这种情况。基因克隆技术：重点介绍了这一新技术在昆虫脑钟、前胸钟和鸟类松果体钟研究中的应用。

Circadian rhythm is an about-24 hr endogenous oscillation underlain by a time measuring mechanism (circadian clock). A strategy for elucidating the mechanism includes three progressive stages: (1) localization of candidate clock tissues, (2) demonstrat-tion of a self-oscillating ability of the tissue, and (3) approaches to deeper mechanisms from aspects of cell or molecular biology. This project team comprised 12 active researchers working along this strategy.Results were obtained as follows.1. Localization of the clock in Metazoa: Self-oscillating ability of the cricket optic lobe were demonstrated alomst conclusively. Interspecies transplantation of the suprachiasmatic nuclei were attempted with rodents. Studies on melatonin production , a key factor for controlling overt rhythms, in the pineal body and the eye of vertebrates were deepened.2. Clocks at cellular level: A molecular-biological study clarified that a clock mutant of a Neurospora rhythm is characterized by an abnormal calcium metabolism. Biophysical mechanisms of Paramecium swimming rhythm were analysed using a computerized system for monitoring cell movements. PTTH cells, which may form an essential part of the insect brain clock, were tried to be located by an immunohistochemical method.3. Photoperiodic clocks: How photoperiodism is related to circadian rhythm was also studied. An interesting result was obtained, in a cricket study,that heavy water lengthened the freerunning period of locomotion but did not affect the critical photoperiod. External coincidence model now widely accepted may not apply to this case.4. Gene cloning techniques: Utility of this newly developed techniques was emphasized in studies on brain and prothoracic clock of insects and bird pineal clock.