Visualization of mPer1 transcription in vitro: NMDA induces a rapid phase shift of mPer1 gene in cultured SCN.
Many physiological and behavioral phenomena are controlled by an internal, self-sustaining oscillator with a periodicity of approximately 24 hr. In mammals, the principal oscillator resides in the suprachiasmatic nucleus (SCN). A light pulse during the subjective night causes a phase shift of the circadian rhythm via direct glutamatergic retinal afferents to the SCN [1]. Along with the accepted theoretical models of the clock, it is suggested that behavioral resetting of mammals is completed within 2 hr [2]; however, the molecular mechanism has not been elucidated. Here, we show the real-time image of the transcription of the circadian-clock gene mPer1 in the cultured SCN by using the transgenic mice that carry a luciferase reporter gene under the control of the mPer1 promoter [3]. The real-time image demonstrates that the mPer1 promoter activity oscillates robustly in a circadian manner and that this promoter activity is reset rapidly (within 2-3 hr) when a phase shift occurs.
Asai
M
M
Division of Molecular Brain Science, Department of Brain Sciences, Kobe University Graduate School of Medicine, Chuo-ku, Kobe 650-0017, Japan.
Yamaguchi
S
S
Isejima
H
H
Jonouchi
M
M
Moriya
T
T
Shibata
S
S
Kobayashi
M
M
Okamura
H
H
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D046508:Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D015870:Gene Expression; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008027:Light; D051379:Mice; D008822:Mice, Transgenic; D016202:N-Methylaspartate / Q000378:metabolism* / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics*; D056950:Period Circadian Proteins; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D018691:Excitatory Amino Acid Antagonists; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; D056950:Period Circadian Proteins; D011500:Protein Synthesis Inhibitors; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D003513:Cycloheximide