Model for spatiotemporal organization of biochemical circadian clocks.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2011)
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|Item Type:||Ph.D. Thesis|
|Title:||Model for spatiotemporal organization of biochemical circadian clocks|
Present models for circadian rhythm generator are not sufficient to explain all the properties of a mechanism of circadian clocks. In this thesis, a new model is presented including a single element consisting of coupled genetic and metabolic oscillators and a net of such elements. The model investigates synchronisation in the net of elements influenced by variability or white noise due to the global and diffusive coupling and the possibility of entrainment of such nets with respect to external perturbations. Period of the single element is in endogenous region of circadian clocks if certain values of coupling parameter are applied. Synchronisation in the net of globally coupled elements influenced by variability is established for the critical coupling coefficient linearly dependant on variability strengths. Formation of spatial patterns is present in the net of diffusively coupled elements with variability and depends on the size of the net and the strength of variability. The optimal size of the net is taken in order to observe the patterns. Noise in mRNA concentration induces the variation of amplitudes for the variables of the metabolic oscillators, while the period of a single element is not perturbed. Synchronisation in the net influenced by noise is better achieved for the globally coupled elements. Entrainments are established for the single element and for the net of elements (with variability or noise) for all variables if the period of external perturbation corresponds to endogenous period (circa 24 hours) and the couplings are applied in the system. The variables of genetic oscillator are not entrained when the period is significantly different from endogenous period, indicating that metabolic oscillator is sensitive to environmental perturbations. Furthermore, differences are observed between two different couplings for both nets, since diffusive coupling is able to induce formation of spatial patterns.
|Place of Publication:||Darmstadt|
|Uncontrolled Keywords:||circadian oscillators, variability, noise|
|Classification DDC:||500 Naturwissenschaften und Mathematik > 530 Physik|
|Divisions:||05 Department of Physics|
|Date Deposited:||10 May 2011 09:45|
|Last Modified:||07 Dec 2012 12:00|
|Referees:||Kaiser, Prof. Dr. Friedemann and Drossel, Prof. Dr. Barbara|
|Refereed:||21 June 2010|