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Updated: May 9, 2026
10:38
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
An in vitro ES cell-based clock recapitulation assay model identifies CK2α as an endogenous clock regulator
Yasuhiro Umemura1, Junko Yoshida, Masashi Wada
1Department of Physiology and Systems Bioscience, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Plos One
|July 11, 2013
Summary
A new in vitro assay confirms Casein Kinase 2 alpha subunit (CK2α) is essential for mammalian circadian clock function. This method enables genetic screening of circadian clock mutations using embryonic stem cells.
Area of Science:
- Chronobiology
- Molecular Biology
- Stem Cell Biology
Background:
- Circadian molecular oscillations emerge during embryonic stem cell differentiation and disappear during cell reprogramming.
- Previous studies indicated the involvement of kinases in regulating circadian rhythms.
Purpose of the Study:
- To develop and validate a robust in vitro assay for studying circadian clock formation.
- To investigate the role of Casein Kinase I delta (CKIδ) and Casein Kinase 2 alpha subunit (CK2α) in circadian rhythmicity.
Main Methods:
- Development of an in vitro circadian clock formation assay using mouse embryonic stem cells (ES cells).
- Phenotypic analysis of wild-type, CKIδ mutant, and CK2α mutant ES cell lines.
- Validation of the assay by comparing results with in vivo data from CKIδ null mice.
Main Results:
- The assay confirmed that CKIδ deficiency leads to a longer circadian period (~3 hours), consistent with previous findings.
- A CK2α homozygous mutant ES cell line exhibited significantly longer circadian periods (~2.5 hours) after differentiation.
- Revertant ES cell lines with deleted mutagenic vector sequences showed near wild-type periods, confirming CK2α's role.
Conclusions:
- The in vitro assay accurately recapitulates in vivo circadian phenotypes.
- CK2α plays an essential role in the mammalian circadian clock, as demonstrated by genetic evidence from the ES cell assay.
- This ES cell-based assay is a valuable tool for circadian genetic screening, especially for essential genes like CK2α.
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