Abstract
Circadian clocks allow eukaryotes to adapt to the daily cycles caused by the Earth's rotation. At the molecular level, circadian oscillators consist of transcriptional-translational negative feedback loops that drive circadian rhythms. Epigenetic regulators coordinate with transcription factors to modulate the rhythmic transcription of circadian clock genes, ensuring proper circadian clock function. In this review, we first provide a brief overview of the epigenetic regulation of circadian clock genes and the conserved circadian oscillators in Neurospora, Drosophila, and mammals. Then, we summarize recent advances in understanding the role of epigenetic regulation in circadian rhythms and how chromatin modifiers interact with core clock proteins to regulate clock gene expression. Finally, we discuss what remains unknown about how chromatin states influence circadian clocks.
