Modeling oscillations and spiral waves in Dictyostelium populations.
Modeling oscillations and spiral waves in Dictyostelium populations.
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DOI：
10.1103/physreve.91.062711
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发表时间：
2015-06
期刊：
影响因子：
--
通讯作者：
Mehta P
中科院分区：
文献类型：
--
作者：
Noorbakhsh J;Schwab DJ;Sgro AE;Gregor T;Mehta P
单细胞生物体表现出复杂的集体行为，以响应环境提示。这些行为由单个细胞内复杂的生化网络控制，并通过细胞间的通讯进行协调。描述这些行为需要新的数学模型，能够跨越尺度--从单个细胞内的生化网络到空间结构的细胞群体。在这里，我们提出了一族“多尺度”的模型，用来描述盘状变形虫中螺旋波的出现。我们的模型利用了新的实验进展，允许直接测量和操纵小信号分子环腺苷一磷酸(CAMP)，Dictyostelials细胞使用cAMP来协调细胞群体的行为。受最近的实验启发，我们将Dictyostelius信号网络建模为一个耦合到各种预处理模块的可兴奋系统。我们使用这一系列模型来研究“固定”细胞的空间非结构化群体，方法是构建相图，将群体水平振荡的特性与潜在生化网络中的参数联系起来。然后，我们将简要讨论包含空间结构的模型的扩展，并说明这是如何自然地产生螺旋波的。我们的模型展示了广泛的新奇现象。包括密度相关的频率变化、双稳态和由于缓慢的cAMP动力学引起的动态死亡。我们的建模方法提供了一个强大的工具，桥接规模，在模型的Dictyostelials种群。
Unicellular organisms exhibit elaborate collective behaviors in response to environmental cues. These behaviors are controlled by complex biochemical networks within individual cells and coordinated through cell-to-cell communication. Describing these behaviors requires new mathematical models that can bridge scales—from biochemical networks within individual cells to spatially structured cellular populations. Here we present a family of “multiscale” models for the emergence of spiral waves in the social amoeba Dictyostelium discoideum. Our models exploit new experimental advances that allow for the direct measurement and manipulation of the small signaling molecule cyclic adenosine monophosphate (cAMP) used by Dictyostelium cells to coordinate behavior in cellular populations. Inspired by recent experiments, we model the Dictyostelium signaling network as an excitable system coupled to various preprocessing modules. We use this family of models to study spatially unstructured populations of “fixed” cells by constructing phase diagrams that relate the properties of population-level oscillations to parameters in the underlying biochemical network. We then briefly discuss an extension of our model that includes spatial structure and show how this naturally gives rise to spiral waves. Our models exhibit a wide range of novel phenomena. including a density-dependent frequency change, bistability, and dynamic death due to slow cAMP dynamics. Our modeling approach provides a powerful tool for bridging scales in modeling of Dictyostelium populations.