Time of day dependent regulation of exercise-induced transcription in the heart

We sought to determine the global transcriptional response to exercise in the heart in a time-of-day dependent manner. To accomplish this, adult male mice (C57Bl/6, ~12 weeks of age) were habituated to treadmill exercise and exposed to a single bout of low-moderate intensity exercise (60 mintue, 10 m/min, 0% grade) at ZT0 (beginning of rest phase) or ZT12 (beginning of active phase). RNA was isolated from whole hearts harvested immediately after exercise (or from sedentary control mice) for RNA-Seq. Overall design: We performed RNA-Seq on 4 biological groups; ZT0-Sed - Sedentary mice at the beginning of the rest phase, ZT0-Ex - Exercised mice at the beginning of the rest phase, ZT12-Sed - Sedentary mice at the beginning of the active phase, ZT12-Ex - Exercised mice at the beginning of the active phase.