Postnatal ontogenesis of molecular clock in mouse striatum.
Striatum is an important brain area whose function is related to motor, emotion and motivation. Interestingly, biological and physiological circadian rhythms have been found in the striatum extensively, suggesting molecular clock machinery works efficiently therein. However, the striatal expression profiles of clock genes have not been characterized systematically. In addition, little is known about when the expression rhythms start during postnatal ontogenesis. In the present study, 24 h mRNA oscillations of 6 principle clock genes (Bmal1, Clock, Npas2, Cry1, Per1 and Rev-erb alpha) were examined in mouse striatum, at early postnatal stage (postnatal day 3), pre-weaning stage (postnatal day 14) and in adult (postnatal day 60). At P3, no daily oscillation was found for all clock genes. At P14, a significant time effect was identified only for Rev-erb alpha and Npas2. At P60, the daily oscillations of these clock genes were at least borderline significant, with peak time at Circadian time (CT) 01 for Bmal1, Clock, Npas2 and Cry1; at CT 13 for Per1; and at CT 07 for Rev-erb alpha. In addition, the overall mean mRNA levels of these clock genes also underwent a dynamic change postnatally. For Bmal1, Clock, Npas2, Per1 and Rev-erb alpha, the expression level increased throughout the postnatal ontogenesis from P3, P14 to P60. For Cry1, however, the abundance at P3 and P60 were similar while that at P14 was much lower. In conclusion, the striatal molecular clock machinery, although works efficiently in adult, develops gradually after birth in mice.
Cai
Yanning
Y
Department of Neurology and Neurobiology, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, 45 Changchun Street, Beijing 100053, PR China.
Liu
Shu
S
Li
Ning
N
Xu
Shengli
S
Zhang
Yanli
Y
Chan
Piu
P
D056930:ARNTL Transcription Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001683:Biological Clocks / Q000235:genetics*; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000235:genetics*; D003342:Corpus Striatum / Q000254:growth & development* / Q000378:metabolism*; D056931:Cryptochromes; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D056950:Period Circadian Proteins; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D056931:Cryptochromes; D004268:DNA-Binding Proteins; D005420:Flavoproteins; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; C538961:Bmal1 protein, mouse; C538964:Cry1 protein, mouse; C491259:Npas2 protein, mouse; C498262:Nr1d1 protein, mouse; C539023:Per1 protein, mouse; C538944:Clock protein, mouse