Identifying Novel Transcriptional Regulators with Circadian Expression

Area of Science:

• Molecular Biology
• Genetics
• Chronobiology

Background:

• Organisms exhibit physiological and behavioral adaptations to the 24-hour day-night cycle, regulated by intrinsic circadian rhythms.
• Cellular circadian rhythms are driven by transcriptional-translational feedback loops orchestrated by core clock genes.
• Knowledge of the full spectrum of genes regulating circadian transcription, including transcription factors and noncoding RNAs, remains incomplete.

Purpose of the Study:

• To discover novel genes, such as transcription factors, epigenetic regulators, and long intergenic noncoding RNAs, involved in circadian transcriptional regulation.
• To investigate the cyclical expression patterns of these newly identified genes in murine fibroblast cells and mouse tissues.
• To explore the functional impact of these genes on the core circadian clock network.

Main Methods:

• High-coverage transcriptome analysis of a circadian time course in murine fibroblast cells.
• Application of a newly developed algorithm to identify cyclically expressed genes.
• Gene knockdown experiments (e.g., Zfp28) and mathematical modeling to predict gene regulatory interactions.

Main Results:

• Identification of numerous cyclically expressed transcription factors, epigenetic regulators, and long intergenic noncoding RNAs.
• Confirmation of circadian expression for a subset of these identified genes in mouse tissues.
• Demonstration that knockdown of Zfp28 impacts the core circadian clock network.
• Mathematical modeling predicted potential regulator-effector interactions among circadian genes.

Conclusions:

• The study successfully identified novel components of the circadian gene regulatory network.
• These findings expand the known players involved in maintaining circadian rhythms at the molecular level.
• The identified genes and predicted interactions provide a foundation for further research into the complex gene regulatory networks governing circadian biology.