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Updated: Jun 2, 2026

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
Understanding systems-level properties: timely stories from the study of clocks
John B Hogenesch1, Hiroki R Ueda
1Department of Pharmacology, Penn Center for Bioinformatics, Penn Genome Frontiers Institute, Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. hogenesc@mail.med.upenn.edu
Abstract:
After several decades dominated by reductionist approaches in biology, researchers are returning to the study of complex biology with a litany of new and old techniques--this paradigm has been termed systems biology. Here we detail how systems biology is being used to uncover complex systems-level properties of the circadian clock. These properties include robustness, periodicity and temperature compensation. We describe how clock researchers are using systems-biology techniques, such as genetic perturbations, kinetic luminescence imaging, synthetic biology and mathematical modelling, to untangle these complex properties in mammals, fungi and bacteria. The strategies developed in the context of circadian clocks may prove useful for tackling similar problems in other systems.
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Linear time-invariant Systems
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated...
Classification of Systems-I
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