Intrinsic fluctuations in stochastic delay systems: Theoretical description and application to a simple model of gene regulation
Intrinsic fluctuations in stochastic delay systems: Theoretical description and application to a simple model of gene regulation
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DOI：
10.1103/physreve.80.021909
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发表时间：
2009-08-01
影响因子：
2.4
通讯作者：
Galla, Tobias
中科院分区：
文献类型：
--
作者：
Galla, Tobias
研究了随机时滞系统中固有噪声的影响。我们表明，潜在动力学的随机性质可能在确定性系统不维持周期的参数范围内诱导振荡行为，并解析地计算这些随机振荡的功率谱，与模拟结果很好地一致。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，但更普遍适用。特别是基因调控系统通常只包含少量分子，导致信使RNA （mRNA）和蛋白质浓度的显著波动。因此，作为一项应用，我们研究了hes1 mRNA和hes1蛋白表达水平的简约模型，代表了一个自抑制反馈回路的简单基序，并被其与somite分割的相关性所激发。
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.