Microbial regulation of vertebrate circadian clocks

项目总结/摘要 在每个细胞内，一个强大的分子钟是由转录-翻译反馈回路建立的， 转录激活复合物CLOCK：BMAL1和阻遏物PER（period）和CRY（cryptochrome） 关闭CLOCK：BMAL1。分子钟控制着超过40%的 使宿主生理与外部环境同步的基因组。这些振荡是自我维持的 在细胞水平上：即使所有外部线索都被移除，昼夜节律也会以类似的时间持续存在， 当外部线索出现时，会与外部线索保持一致，这一特征被称为夹带。在哺乳动物中，昼夜节律的诱导 阻遏物PER是夹带的普遍第一步。微生物在我们的环境中无处不在， 经历与24小时太阳周期相关的每日波动，但目前尚不清楚微生物暴露 影响昼夜节律。这项研究将探索微生物浓度如何影响细胞信号传导 级联负责夹带，并将定义新的先天调节器的时钟。另外这些 研究将利用斑马鱼的遗传和实验易处理性来执行高通量、真实的时间 体内昼夜节律反应的动力学。在斑马鱼身上进行全身非侵入性成像的能力 与已建立的鼠模型相比具有显著的优势， 例如免疫细胞。此外，作为一种非哺乳类的冷血脊椎动物， 斑马鱼的生物钟也代表了一个难以置信的机会，可以弥合大多数生物之间的进化差距。 良好表征的动物系统：果蝇（无脊椎动物）和小鼠（脊椎动物，哺乳动物）。在一起，这 研究将推进我们对脊椎动物生物钟的基本理解，以及它是如何整合的。 关于微生物刺激在分子水平上携带细胞时钟的信息。

Project Summary/Abstract Within each cell, a robust molecular clock is established by transcription-translation feedback loops driven by the transcriptional activation complex CLOCK:BMAL1 and the repressors PER (period) and CRY (cryptochrome) that turn CLOCK:BMAL1 “off”. The molecular clock controls daily oscillations in the expression of over 40% of the genome to synchronize host physiology with the external environment. These oscillations are self-sustaining on the cellular level: circadian rhythms persist with similar timing even when all external cues are removed, but will align with external cues when present, a feature called entrainment. In mammals, induction of the circadian repressor PER is a universal first step in the entrainment. Microbes are ubiquitous in our environment and undergo daily fluctuations correlated with the 24-hour solar cycle, but it is not known how microbial exposure impacts circadian rhythms. This research will explore how microbial concentration affects cellular signaling cascades responsible for entrainment and will define novel innate regulators of the clock. In addition, these studies will leverage the genetic and experimental tractability of zebrafish to perform high throughput, real time kinetics of circadian responses in vivo. The ability to do whole body, non-invasive imaging in zebrafish has significant advantages over established murine models and is particularly advantageous for migratory populations such as immune cells. Furthermore, as a non-mammalian, cold-blooded vertebrate, the study of clocks in zebrafish also represents an incredible opportunity to bridge the evolutionary gap between the most well characterized animal systems: Drosophila (invertebrate) and mice (vertebrate, mammal). Together, this research will advance our fundamental understanding of vertebrate circadian clocks and how it integrates information about microbial stimulation to entrain cellular clocks at the molecular level.