CIRCADIAN CONTROL. “Circadian pacemaker in the suprachiasmatic nuclei shows phase plasticity with winter and summer photoperiod in seasonal mammals. In vertebrates, the circadian molecular oscillator is based on transcriptional-translational feedback loops, in which periods and cryptochromes are negative regulators of their own transcription driven by brain and muscle arnt-like protein 1 (Bmal1) and circadian locomotor output cycles kaput (Clock) transcriptional activators.”
http://www.fasebj.org/content/29/10/4248.full