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Updated: Jul 31, 2026

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
[Aging and circadian clock gene expression in peripheral tissues in rats]
F Claustrat1, I Fournier, G Geelen
1Service de radioanalyse, hôpital cardiologique, 59, boulevard Pinel, 69677 Bron cedex, France. francine.claustrat@chu-lyon.fr
Abstract:
Aging is associated with alterations of the circadian rhythms (shortened amplitude and phase-advance). We studied by quantitative RT-PCR the influence of aging on the expression of circadian clock genes (Clock, Bmal1, Cry1,2, Per1-3) in peripheral tissues (liver and heart) of middle-aged (13 months) and old (27 months) rats of the Wag/Rij strain exposed to a 12 hours light/12 hours dark cycle. Rats were killed at the light-dark transition (8 am and 8 pm). In the liver, Per, Cry et Bmal1 genes showed a morning/evening difference of expression; in addition, old rats exhibited a significant decrease of Per gene expression in the evening vs middle-aged rats. The heart showed similar profiles with only a tendency toward a decrease of Per expression and an increased Bmal1 expression in the evening in old rats. These results show that aging is associated with circadian gene expression changes.
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