PHOTORECEPTORS INVOLVED IN CHLAMYDOMONAS REINHARDTII CIRCADIAN ENTRAINMENT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 这项拟议研究的长期目标是阐明莱茵衣藻生物钟背后的生化机制。这种单细胞、真核绿藻作为动植物许多细胞过程的模型系统。了解它的生物钟将有助于理解生物钟的进化，从而也有助于更好地理解人类的生物钟。实现长期目标的策略是确定负责调整生物钟以适应每日明/暗周期的光感受器(S)。如果成功，光感受器可以被用作研究信号转导链(S)的手柄，该链将信息传递到中央振荡器，可能还包括振荡器本身的组件。与其他模式生物如拟南芥相比，莱茵哈迪尔锥虫具有优势，因为它只含有有限数量的光感受器。它们分为三类：隐色素类、视紫红质类和耳促素类。趋光素是在高等植物和绿藻中发现的蓝光感受器(Briggs和Christie 2002)。趋光性激素是否参与昼夜节律时钟的光携带尚不完全清楚。另一方面，隐色素是蓝光感受器，被证明参与高等植物和昆虫的生物钟携带(Cashmore 2003)。在哺乳动物中也发现了它们，但它们是起搏器的组成部分，在这类生物体中创造了昼夜振荡。在真菌中，如粗糙脉孢菌，隐花色素似乎与生物钟无关。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term objectives of the proposed research are to elucidate the biochemical mechanisms underlying the circadian clock in Chlamydomonas reinhardtii. This unicellular, eukaryotic green alga serves as a model system for a number of cell processes in animals and plants. Understanding its circadian clock will contribute to an understanding of circadian clock evolution and thus also help to better understand the circadian clock in humans. The strategy of achieving the long-term objectives is to identify the photoreceptor(s) responsible for adjusting the circadian clock to the daily light/dark cycles. If successful, the photoreceptors can be used as a handle to investigate the signal transduction chain(s) that convey the information to the central oscillator and possibly the components of the oscillator itself. C. reinhardtii provides an advantage over other model organisms such as Arabidopsis thaliana because it contains only a limited number of photoreceptors. They fall into three classes: cryptochromes, rhodopsins, and ototropins. Phototropins are blue-light photoreceptors found in higher plants and green algae (Briggs and Christie 2002). Whether phototropins are involved in lightentrainment of the circadian clock is not completely understood yet. Cryptochromes on the other hand are blue-light photoreceptors that were shown to be involved in clock entrainment in higher plants and insects (Cashmore 2003). They are also found in mammals but serve as components of the pacemaker that creates the circadian oscillation in this group of organisms. In fungi as exemplified by Neurospora crassa, cryptochrome seems not to be involved in the circadian clock.