Differential daily expression of Per1 and Per2 mRNA in the suprachiasmatic nucleus of fetal and early postnatal mice.
It is well known that there are circadian rhythms of 2-deoxyglucose uptake and neuronal firing in the rat suprachiasmatic nucleus (SCN) during fetal and early postnatal periods. A core clock mechanism in the mouse SCN appears to involve a transcriptional feedback loop in which CLOCK and BMAL1 function as positive regulators and three mPeriod (mPer) genes play a role in negative feedback. Per genes expression occurs not only in the adult SCN but also in the fetal SCN. However, the developmental change in these genes remains unclear. In this experiment, we examined the day--night pattern of expression of Per1 and Per2 mRNA in the mouse SCN and cerebral cortex on embryonic day 17, postnatal day 3, and in young adult mice under a light-dark cycle. Daily rhythms of mRNA content were observed in mPer1 but not mPer2 in the fetal SCN. Interestingly, the expression of mPer2 in the SCN was high throughout the entire day, and a significant daily rhythm of this gene was observed on postnatal day 6. The expression pattern of SCN mPer1 in constant darkness was similar to that seen in the light-dark cycle. The present results suggest that the daily oscillation of mPer1 but not of mPer2 in the SCN in fetal and early postnatal mice may be associated with the daily rhythms of 2-deoxyglucose uptake and neuronal firing.
Shimomura
H
H
Department of Pharmacology and Brain Science, School of Human Science, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan.
Moriya
T
T
Sudo
M
M
Wakamatsu
H
H
Akiyama
M
M
Miyake
Y
Y
Shibata
S
S
D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D018797:Cell Cycle Proteins; D002540:Cerebral Cortex / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics* / Q000528:radiation effects; D003624:Darkness; D005246:Feedback; D005260:Female; D005326:Fetal Proteins / Q000096:biosynthesis* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D056950:Period Circadian Proteins; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D013493:Suprachiasmatic Nucleus / Q000196:embryology / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D015534:Trans-Activators / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D018797:Cell Cycle Proteins; D005326:Fetal Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; C538960:BMAL1 protein, human; C538961:Bmal1 protein, mouse; C539022:PER1 protein, human; C539023:Per1 protein, mouse; C539024:Per1 protein, rat; C513312:Per2 protein, mouse; C513311:Per2 protein, rat; C538943:CLOCK protein, human; C538944:Clock protein, mouse; C538945:Clock protein, rat