Entrainment of mouse peripheral circadian clocks to <24 h feeding/fasting cycles under 24 h light/dark conditions

Sci Rep. 2015 Sep 23;5:14207. doi: 10.1038/srep14207.


The circadian clock system in peripheral tissues can endogenously oscillate and is entrained by the light-dark and fasting-feeding cycles in mammals. Although the system's range of entrainment to light-dark cycles with a non-24 h (<24 h) interval has been studied, the range of entrainment to fasting-feeding cycles with shorter periods (<24 h) has not been investigated in peripheral molecular clocks. In the present study, we measured this range by monitoring the mouse peripheral PER2::LUCIFERASE rhythm in vivo at different periods under each feeding cycle (Tau (T) = 15-24 h) under normal light-dark conditions. Peripheral clocks could be entrained to the feeding cycle with T = 22-24 h, but not to that with T = 15-21 h. Under the feeding cycle with T = 15-18 h, the peripheral clocks oscillated at near the 24-h period, suggesting that they were entrained to the light-dark cycle. Thus, for the first time, we demonstrated the range of entrainment to the non-24 h feeding cycle, and that the circadian range (T = 22-24 h) of feeding stimulus is necessary for peripheral molecular clock entrainment under light-dark cycles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Circadian Clocks / physiology*
  • Circadian Rhythm / physiology*
  • Fasting / physiology
  • Feeding Behavior / physiology*
  • Gene Knock-In Techniques
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Photoperiod*