钟基因Chrono调节哺乳动物生物节律的分子机制研究

生物钟节律的分子机制中，负反馈元件对转录激活因子的调控和对染色质转录的调控是关键步骤；另外，生物钟元件在机体适应外界环境因子中发挥的作用是理解生物钟调节机体生理的关键基础。新近发现的一个新的生物钟元件，CHRONO，在哺乳动物组织中广泛表达，参与调节生物节律。课题组的前期工作发现CHRONO与BMAL1作用的最小结构域，并发现CRISPR/Cas9敲除Chrono基因对周期有显著影响。然而，CHRONO对BMAL1/CLOCK转录调控的分子机制，在染色质水平与DNA的动态结合，以及在机体受外界环境因子牵引过程中发挥什么功能，却并不清楚。课题组拟综合应用生物化学，细胞生物学，基因编辑和高通量测序，条件性基因敲除小鼠，小鼠生物钟行为监测等技术，在分子和生理水平，系统阐述Chrono参与调控生物节律的分子机制，理解Chrono在参与限制性喂食引发的食物预期活动和动物适应光照环境因子中发挥的作用。

In the molecular mechanism of the circadian clock rhythm, chromatin transcription regulations and the negative feedback regulations to the transcription activators are the key steps; in addition, roles of the clock elements in the organisms’ adaptation to environmental factors are the key bases for understanding how the circadian clock regulates the physiology. A novel discovered circadian clock element, CHRONO, is widely expressed in mammalian tissues and is involved in regulating biological rhythms. Our very recent work has found that the minimal domain responsible for the interaction between CHRONO and BMAL1 and that CRISPR/Cas9 knockout of the Chrono gene has a significant impact on the circadian period. However, the molecular mechanism of how CHRONO transcriptionally regulates BMAL1/CLOCK complexes, and its dynamic binding to DNA at the genomic level, and what function it plays during the entrainment by environmental factors are unclear. We aim to comprehensively apply biochemistry, cell biology, gene editing and high-throughput sequencing, conditional gene knockout mice, mouse circadian clock behavior monitoring and other technologies to systematically elaborate Chrono's participation in regulating the circadian rhythm. Furthermore, we intend to understand the role of Chrono in participating in the food anticipatory activities induced by restrict feeding and its role in entrainment by the light/dark cycling environment.