Energy balance influences daily patterns of gene activity in daytime and nighttime brain systems

Rhythmic gene expression was analyzed in 21 tissues of male CBA/CaJ mice sampled every 4 hours over a 24-hour period.

• Distinct sets of genes were expressed rhythmically in nocturnal versus diurnal mice, with minimal overlap.
• Changes in non-clock genes were observed in the suprachiasmatic nucleus, indicating a role in daily activity timing.
• The habenula showed the most significant changes, suggesting its importance in regulating the nocturnal-diurnal switch.
• Adaptive flexibility in behavior timing may be supported by dynamic gene expression across various tissues and brain regions.

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