Embryo as an active granular fluid: stress-coordinated cellular constriction chains
Embryo as an active granular fluid: stress-coordinated cellular constriction chains
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DOI：
10.1088/0953-8984/28/41/414021
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发表时间：
2016-10-19
影响因子：
2.7
通讯作者：
Blawzdziewicz, Jerzy
中科院分区：
文献类型：
--
作者：
Gao, Guo-Jie Jason;Holcomb, Michael C.;Blawzdziewicz, Jerzy
机械应力在单个细胞的基因表达和发育中的组织造型中起着复杂的作用。然而，研究机械应力和反馈如何帮助协调组织内的细胞活动的系统方法尚未开发出来。基于我们对果蝇胚胎腹侧皱纹形成初期细胞收缩链(CCCS)的观察，我们提出了一个活跃的颗粒流(AGF)模型，该模型对顶端收缩过程中的细胞协调提供了有价值的见解。在我们的模型中，细胞被视为由预定义的力网络连接的圆形粒子，它们经历了一个随机收缩过程，其中粒子收缩概率P是其相邻粒子施加在粒子上的应力的函数。我们发现，当P有利于拉应力时，被压缩的颗粒倾向于形成链状结构。相反，当P有利于压缩时，被压缩的粒子倾向于形成致密的团簇。在体内观察到的收缩粒子链和CCCS的显著相似性提供了间接证据，表明拉伸-应力反馈协调了心尖收缩活动。我们的基于粒子的AGF模型将有助于分析各种形态发生和器官发生现象中的机械反馈效应。
Mechanical stress plays an intricate role in gene expression in individual cells and sculpting of developing tissues. However, systematic methods of studying how mechanical stress and feedback help to harmonize cellular activities within a tissue have yet to be developed. Motivated by our observation of the cellular constriction chains (CCCs) during the initial phase of ventral furrow formation in the Drosophila melanogaster embryo, we propose an active granular fluid (AGF) model that provides valuable insights into cellular coordination in the apical constriction process. In our model, cells are treated as circular particles connected by a predefined force network, and they undergo a random constriction process in which the particle constriction probability P is a function of the stress exerted on the particle by its neighbors. We find that when P favors tensile stress, constricted particles tend to form chain-like structures. In contrast, constricted particles tend to form compact clusters when P favors compression. A remarkable similarity of constricted-particle chains and CCCs observed in vivo provides indirect evidence that tensile-stress feedback coordinates the apical constriction activity. Our particle-based AGF model will be useful in analyzing mechanical feedback effects in a wide variety of morphogenesis and organogenesis phenomena.