Deterministic versus stochastic models for circadian rhythms.

摘要: Circadian rhythms which occur with a period close to 24 h in nearly all living organisms originate from the negative autoregulation of gene expression.Deterministic models based on genetic regulatory processes account for theoccurrence circadian constant environmental conditions (e.g.constant darkness), entrainment these by light-dark cycles, and their phase-shifting light pulses. At low numbers protein mRNA molecules, it becomes necessary resort stochastic simulations assess influence molecular noise oscillations. We address effect considering two versions core model rhythms. The deterministic version this modelwas previously proposed oscillations PER Drosophila FRQ Neurospora. In first, non-developed model, we introduce without decomposing mechanism into detailed reaction steps while second, developed carry out such decomposition. Numerical are performed means Gillespie method. compare predictions approach those models, respect both sustained limit cycle type proximity bifurcation point beyond system evolves stable steady state. results indicate that robust can even when nuclear involved oscillatory reduced few tens orhundreds, respectively. yield largely similar provide good agreement