Mouse Period1 (mPER1) acts as a circadian adaptor to entrain the oscillator to environmental light/dark cycles by regulating mPER2 protein.
Mouse period1 (mPer1) and mPer2 are mammalian homologs of the Drosophila clock gene period that show robust oscillation in the suprachiasmatic nucleus, the mammalian master clock, and have been implicated as essential components of the core clock mechanism. Gene-targeting studies have demonstrated that mPer2 plays a dominant function in behavioral rhythm generation, although the role of mPer1 has not been fully clarified. Here, we report that prolongation of the lighting period (4-16 h) induces a larger-delay phase shift of the behavioral rhythm in mPer1-deficient (mPer1-/-) mice. During the light-elongation task, mPER2 protein decay in mPer1-/- mice is slower (approximately 4 h) than in wild-type mice, which thereby causes larger behavioral phase delay. mPer1-/- mice could not adapt to environmental light/dark cycles in long complete photoperiods with dim light or in long skeleton photoperiods. These photoperiodic conditions mimic natural environmental changes present at high latitudes, indicating that mPer1 could operate in the adaptation of the circadian clock of nocturnal mice to large seasonal changes of environmental light/dark cycles.
Masubuchi
Satoru
S
Division of Molecular Brain Science, Department of Brain Sciences, Kobe University Graduate School of Medicine, Chuo-ku, Kobe 650-0017, Japan.
Kataoka
Noritoshi
N
Sassone-Corsi
Paolo
P
Okamura
Hitoshi
H
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics / Q000528:radiation effects*; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000235:genetics / Q000502:physiology; D009687:Nuclear Proteins / Q000172:deficiency / Q000378:metabolism* / Q000502:physiology*; D056950:Period Circadian Proteins; D010775:Photic Stimulation / Q000379:methods; D017440:Photoperiod; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013493:Suprachiasmatic Nucleus / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology*
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D014157:Transcription Factors