Fluid flows controlling morphology: How flows coordinate the collective behaviour of protrusions for directed migration

流体流动控制形态：流动如何协调突起的集体行为以进行定向迁移

• 批准号: 443740179
• 负责人: Professorin Dr. Karen Alim
• 金额: --
• 依托单位: Arbeitsgruppe Theorie biologischer Netzwerke
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/443740179?language=en
• 关键词: Fluid; flows; controlling; morphology; How

Living systems are often challenged to coordinate collective behaviour of individual entities across large spatial scales. The morphology of amoeboid cells, for example, arises due to the coordination of randomly forming protrusions that facilitates the cell's directed migration. To propagate information across large scales, fluid flows can be instrumental as they may transport signalling molecules or rapidly propagate changes in pressure. Yet, the dynamic nature of flows and the associated challenges in imaging them has so far limited our understanding on their role in coordinating collective behaviour and morphology.The slime mould Physarum polycephalum grows as a single giant cell of network-like shape spanning orders of magnitude in size from 500 µm to tens of cm in size. Due to the large extent, chemotaxis and morphogenesis of the entire cell require a mechanism for coordination among competing protrusions. P. polycephalum is renowned for its organism-wide cytoplasmic fluid flows spanning the fluid-filled tubular network in a peristaltic wave. These strong and large-scale flows make this organism an ideal model to investigate the role of fluid flows in coordinating the collective behaviour of competing protrusions during the morphological changes in chemotaxis.We will perform experiments of chemotacting P. polycephalum specimen of varying sizes and quantify the dynamics of individual protrusions in addition to the chemotactic performance of the entire specimen. Correlations between growing and retracting protrusions over time will lead us to identify the mechanism of communication which could be either diffusive or flow-based transport of an inhibitory signal or simply hydrodynamic coupling within the closed system of a single cell. Theoretical simulations of the identified mechanism will confirm our findings and broaden our analysis to understand the mechanisms' robustness. The project will teach us how fluid flows control collective behaviour of protrusions during directed migration. The theoretical framework being devised allows us to readily adapt cell morphology and boundary conditions to test for the identified principles in other systems.

生命系统往往面临的挑战是在大的空间尺度上协调个体实体的集体行为。例如，变形虫细胞的形态是由于随机形成的突起的协调而产生的，这些突起促进了细胞的定向迁移。为了在大尺度上传播信息，流体流动可以是有用的，因为它们可以传输信号分子或快速传播压力变化。然而，流动的动态性质和成像方面的相关挑战限制了我们对它们在协调集体行为和形态学中的作用的理解。黏菌多头绒泡菌（Physarum polycephalum）生长为单个网状巨细胞，大小从500微米到几十厘米不等。由于在很大程度上，整个细胞的趋化性和形态发生需要竞争突起之间的协调机制。P. polycephalum以其生物体范围内的细胞质流体以蠕动波跨越充满流体的管状网络而闻名。这些强大的和大规模的流动使这种生物体的理想模型，以调查的作用，协调的集体行为的竞争突起的形态变化在chemotaxis.We将进行实验的chemotacting P. polycephalum标本的不同大小和量化的动力学除了整个标本的趋化性能的单个突起。随着时间的推移，生长和收缩突起之间的相关性将使我们确定通信的机制，该机制可以是抑制信号的扩散或基于流动的运输，或者简单地是单细胞封闭系统内的流体动力学耦合。所确定的机制的理论模拟将证实我们的研究结果，并扩大我们的分析，以了解机制的鲁棒性。该项目将教我们流体流动如何控制定向迁移过程中突起的集体行为。正在设计的理论框架使我们能够很容易地适应细胞形态和边界条件，以测试在其他系统中确定的原则。