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Circadian Entrainment of Drosophila Melanogaster
Published on: June 3, 2020
Internal noise-sustained circadian rhythms in a Drosophila model
1School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing, China. qsli@bit
Biophysical Journal
|November 13, 2007
Summary
Internal noise can sustain reliable 24-hour circadian rhythms in Drosophila models, even when deterministic models fail. Optimal noise levels enhance oscillations, demonstrating noise
Area of Science:
- Systems biology
- Chronobiology
- Biophysics
Background:
- Circadian rhythms are molecularly regulated by gene expression with inherent stochasticity.
- Previous research focused on the robustness of circadian rhythms against internal noise.
- The constructive roles of internal noise in circadian systems remain less explored.
Purpose of the Study:
- To investigate the constructive role of internal noise in a reduced Drosophila circadian model.
- To analyze how internal noise sustains reliable oscillations and affects their amplitude and coherence.
- To examine the influence of time delays in feedback loops on noise-sustained oscillations.
Main Methods:
- Development of a reduced Drosophila circadian model with delayed negative and positive feedback loops.
- Stochastic simulations to analyze the effects of internal noise on system dynamics.
- Investigation of parameter space to identify conditions for noise-sustained oscillations and coherence resonance.
Main Results:
- Internal noise sustains reliable circadian oscillations (near 24 h) in parameter regions where deterministic models yield stable steady states.
- An optimal internal noise intensity was identified, leading to intrinsic coherence resonance and maximal oscillation amplitude.
- In the deterministic oscillatory region, increasing noise suppressed coherence but maintained period robustness, highlighting model resilience.
- Time delays in positive feedback loops were found to effectively tune the performance of noise-sustained oscillations.
Conclusions:
- Internal noise plays a constructive role in maintaining circadian rhythms, not just a disruptive one.
- The Drosophila circadian model exhibits coherence resonance and robustness to intrinsic noise.
- Time delays are critical parameters for modulating noise-driven circadian dynamics, offering insights into regulatory system design.
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