Molecular mechanisms in the Arabidopsis circadian clock

描述（由申请人提供）：本提案的长期目标是了解真核细胞如何构建生物钟。众所周知，昼夜节律钟调节着广泛分布于生物学中的许多基本细胞过程。在高等植物中，生物钟参与调节各种过程，从光合作用到开花时间的控制。我们选择拟南芥作为模式生物，并从突变分析中确定了几个时钟基因。这些生物钟基因的调控定义了一个分子反馈回路，形成了高等植物生物钟模型的基础。本提案中的实验旨在通过继续识别时钟因素并确定其在昼夜节律系统中的位置来建立当前的时钟模型。高等植物的生物钟调节着大量的基因，利用基因组学方法来识别生物钟调节的基因为生物钟生物学家提供了一个强大的工具。该提案将通过分析目前市售的拟南芥全基因组芯片，扩展我们与昼夜节律基因组学的初步实验。通过调查受生物钟调控的基因，我们将确定新的生物钟相关因素，并确定它们在昼夜节律系统中的位置。此外，最近的研究结果已经确定了参与开花时间光周期控制的关键蛋白质。本提案中的实验将进一步剖析时钟和开花时间之间的分子通讯。鉴于昼夜节律调节生理学的普遍存在，模式生物中昼夜节律系统的特征将影响对起搏器机制和与人类健康已知特征相关的故障的理解。

DESCRIPTION (provided by applicant): The long term goal of this proposal is to understand how circadian clock are built into eukaryotic cells. Circadian clocks are known to regulate many essential cellular processes widely distributed across biology. In higher plants, the clock is involved in regulating diverse processes ranging from photosynthesis to control of flowering time. We have chosen Arabidopsis as a model organism and have identified several clock genes from mutational analysis. The regulation of these clock genes has defined a molecular feedback loop which forms the basis for models of the clock in higher plants. The experiments in this proposal aim to build on the current clock model by continuing to identify clock factors and determine their position within the circadian system. The circadian clock in higher plants regulates a vast number of genes and utilizing genomics approaches to identify clock-regulated genes has provided clock biologists with a powerful tool. This proposal will extend our initial experiments with Circadian Genomics by analyzing the Arabidopsis full genome chip now commercially available. By surveying genes that are regulated by the clock, we will identify novel clock associated factors and define their positions within the circadian system. In addition, recent results have identified key proteins involved in the photoperiodic control of flowering time. Experiments in this proposal will further dissect the molecular communication between the clock and flowering time. Given the ubiquity of circadian-regulated physiology, characterization of circadian systems in model organisms will impact on understanding of the pacemaker mechanisms and malfunctions associated with known features of human well-being.