Day length influences the liver’s internal clock through the brain’s master clock and feeding patterns in mice

Changes in photoperiod from short to long resulted in significant desynchronization of gene expression profiles in the suprachiasmatic nucleus (SCN) within 5 days.

• Gene expression profiles of Per2 and Rev-erbα in the SCN became desynchronized after transitioning from short to long photoperiod.
• The modulation of the hepatic clock is influenced by the SCN, independent of feeding changes.
• In mice maintained on a short photoperiod with a nighttime feeding schedule, SCN profiles remained unaffected.
• When mice switched to a long photoperiod and fed during the daytime, liver gene expression profiles were altered while SCN profiles remained stable.
• The findings suggest that the SCN can influence liver gene expression through signals that do not rely on food intake.

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