Circadian rhythms are 24-hour oscillations affecting an organism at multiple levels from gene expression all the way to tissues and organs. They have been observed in organisms across the kingdom of life, spanning from cyanobacteria to humans. In mammals, the master circadian pacemaker is located in the hypothalamic suprachiasmatic nuclei (SCN) in the brain where it synchronizes the peripheral oscillators that exist in other tissues. This system regulates the circadian activity of a large part of the transcriptome and recent findings indicate that almost every cell in the body has this clock at the molecular level. In this review, we briefly summarize the different factors that can influence the circadian transcriptome, including light, temperature, and food intake. We then summarize recently identified general principles governing genome-scale circadian regulation, as well as future lines of research. Genome-scale circadian activity represents a fascinating study model for computational biology. For this purpose, systems biology methods are promising exploratory tools to decode the global regulatory principles of circadian regulation.

昼夜节律是24小时的振荡，从基因表达到组织和器官，从多个层面影响生物体。在从蓝细菌到人类的整个生命王国的有机体中均已观察到它们。在哺乳动物中，昼夜节律起搏器位于大脑的下丘脑上交叉气核（SCN）中，在那里与存在于其他组织中的外围振荡器同步。该系统调节大部分转录组的昼夜节律活动，最近的发现表明，体内几乎每个细胞在分子水平上都有这个时钟。在本文中，我们简要总结了影响昼夜节律转录组的各种因素，包括光照，温度和食物摄入量。然后，我们总结了最近确定的控制基因组规模的昼夜节律调节的一般原则，以及未来的研究方向。基因组规模的昼夜节律活动代表了一个有趣的计算生物学研究模型。为此，系统生物学方法是有前途的探索性工具，可用于解码昼夜节律的全球监管原则。