Novel Insights into the Circadian Rhythms Based on Long Noncoding and Circular RNA Profiling

Area of Science:

• Animal models
• Epigenetics
• Chronobiology

Background:

• Circadian rhythm disorders present significant risks to human health and animal production.
• The hypothalamus is central to circadian rhythm regulation.
• Epigenetic regulation of circadian rhythms in farm animals remains understudied.

Purpose of the Study:

• To investigate the epigenetic mechanisms of circadian rhythm regulation in chickens.
• To identify novel noncoding RNA (ncRNA) and mRNA biomarkers associated with the light/dark cycle.
• To explore the role of ncRNAs in regulating circadian rhythm and related metabolic pathways.

Main Methods:

• Collected chicken hypothalamus samples across a 24-hour light/dark cycle.
• Performed comprehensive sequencing of long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and messenger RNAs (mRNAs).
• Utilized differential expression and circadian analysis to identify regulatory networks.

Main Results:

• Identified two gene sets (circadian rhythm and retinal metabolism) linked to the light/dark cycle.
• Discovered noncoding RNA networks with circadian expression patterns, including 38 lncRNAs, 15 circRNAs, and 200 candidate genes.
• Pinpointed three lncRNAs and one circRNA as key regulators of circadian rhythm by influencing AOX1 in retinal metabolism.

Conclusions:

• The study provides insights into the epigenetic regulation of circadian rhythms using a chicken model.
• Identified specific lncRNAs and circRNAs involved in circadian rhythm control.
• AOX1 is highlighted as a potential therapeutic target for circadian rhythm regulation and related disorders.