Altered body mass regulation in male mPeriod mutant mice on high-fat diet.

The circadian clock orchestrates most physiological processes in mammals. Disruption of circadian rhythms appears to contribute to the development of obesity and metabolic syndrome. The Period genes mPer1 and mPer2, but not mPer3, are essential for core clock function in mice. To assess the impact of mPer genes on body mass regulation, mPer mutant and control mice were fed a high-fat diet. Here the authors report that male mPer1/2/3 triple-deficient mice gain significantly more body mass than wild-type controls on high-fat diet. Surprisingly, mPer3 single-deficient animals mimicked this phenotype, suggesting a previously unrecognized role for mPer3 in body mass regulation.