Development of the circadian oscillator during differentiation of mouse embryonic stem cells in vitro.
The molecular oscillations underlying the generation of circadian rhythmicity in mammals develop gradually during ontogenesis. However, the developmental process of mammalian cellular circadian oscillator formation remains unknown. In differentiated somatic cells, the transcriptional-translational feedback loops (TTFL) consisting of clock genes elicit the molecular circadian oscillation. Using a bioluminescence imaging system to monitor clock gene expression, we show here that the circadian bioluminescence rhythm is not detected in the mouse embryonic stem (ES) cells, and that the ES cells likely lack TTFL regulation for clock gene expression. The circadian clock oscillation was induced during the differentiation culture of mouse ES cells without maternal factors. In addition, reprogramming of the differentiated cells by expression of Sox2, Klf4, Oct3/4, and c-Myc genes, which were factors to generate induced pluripotent stem (iPS) cells, resulted in the re-disappearance of circadian oscillation. These results demonstrate that an intrinsic program controls the formation of the circadian oscillator during the differentiation process of ES cells in vitro. The cellular differentiation and reprogramming system using cultured ES cells allows us to observe the circadian clock formation process and may help design new strategies to understand the key mechanisms responsible for the organization of the molecular oscillator in mammals.
Yagita
Kazuhiro
K
Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. kyagita@anat1.med.osaka-u.ac.jp
Horie
Kyoji
K
Koinuma
Satoshi
S
Nakamura
Wataru
W
Yamanaka
Iori
I
Urasaki
Akihiro
A
Shigeyoshi
Yasufumi
Y
Kawakami
Koichi
K
Shimada
Shoichi
S
Takeda
Junji
J
Uchiyama
Yasuo
Y
D000818:Animals; D001683:Biological Clocks / Q000235:genetics; D002454:Cell Differentiation; D002460:Cell Line; D002940:Circadian Rhythm; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D049449:Luminescence; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology
C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; C489428:Myc protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D014212:Tretinoin