Galla Tobias
Theoretical Physics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Aug;80(2 Pt 1):021909. doi: 10.1103/PhysRevE.80.021909. Epub 2009 Aug 12.
The effects of intrinsic noise on stochastic delay systems is studied within an expansion in the inverse system size. We show that the stochastic nature of the underlying dynamics may induce oscillatory behavior in parameter ranges where the deterministic system does not sustain cycles, and compute the power spectra of these stochastic oscillations analytically, in good agreement with simulations. The theory is developed in the context of a simple one-dimensional toy model, but is applicable more generally. Gene regulatory systems in particular often contain only a small number of molecules, leading to significant fluctuations in messenger RNA (mRNA) and protein concentrations. As an application we therefore study a minimalistic model of the expression levels of hes1 mRNA and Hes1 protein, representing the simple motif of an autoinhibitory feedback loop and motivated by its relevance to somite segmentation.
在系统规模倒数展开的框架内，研究了内禀噪声对随机延迟系统的影响。我们表明，基础动力学的随机性可能在确定性系统无法维持周期的参数范围内诱发振荡行为，并通过解析计算这些随机振荡的功率谱，结果与模拟结果高度吻合。该理论是在一个简单的一维玩具模型的背景下发展起来的，但具有更广泛的适用性。特别是基因调控系统通常只包含少量分子，导致信使核糖核酸（mRNA）和蛋白质浓度出现显著波动。因此，作为一个应用，我们研究了hes1 mRNA和Hes1蛋白表达水平的简约模型，该模型代表了自抑制反馈回路的简单基序，并因其与体节分割的相关性而受到启发。
