20-BBSRC/NSF-BIO: Synthetic Control of Pattern Formation and Morphogenesis in a Purposefully Rewired Vertebrate Cell

细胞皮层负责以适当的机械行为响应各种内部和外部信号。这些行为包括细胞分裂，细胞运动和短期或长期的细胞形状变化。我们和其他人最近发现了一个动力学过程皮层兴奋性，各种类型的细胞利用它来驱动不同的机械行为。皮质兴奋性向外表现为肌动蛋白组装的皮质波传播和控制肌动蛋白组装的各种大分子的互补波。皮层兴奋性本身受耦合的快速正反馈和延迟负反馈控制。我们将开发在通常不显示皮质兴奋性的细胞（即青蛙卵母细胞）中合成诱导皮质兴奋性的方法，并采用高分辨率活细胞成像来捕捉兴奋性的详细特征。诱导将基于经工程化以产生快速正反馈或延迟负反馈的合成蛋白质构建体。通过组合不同的合成构建体，我们将驱动简单的细胞形状变化（即，开沟）或复杂的细胞形状变化（即，原肠胚形成），使我们能够测试关于细胞形状控制的基本想法。此外，通过迭代地将实验与计算建模相结合，将有可能对细胞分裂和形态发生等过程进行定量和机械的理解。

The cell cortex is responsible for responding to a variety of internal and external signals with the appropriate mechanical behavior. Such behaviors include cell division, cell locomotion and short or long-term cell shape changes. We and others have recently discovered a dynamical process-cortical excitability-that a variety of cell types harness to drive distinct mechanical behaviors. Cortical excitability is outwardly manifest as propagating cortical waves of actin assembly and complementary waves of the various macromolecules that control actin assembly. Cortical excitability is itself controlled by coupled fast positive feedback and delayed negative feedback. We will develop the means to synthetically induce cortical excitability in cells that do not normally display it, namely, frog oocytes, and employ high-resolution live cell imaging to capture the detailed features of excitability. The induction will be based on synthetic protein constructs engineered to produce either fast positive feedback or delayed negative feedback. By combining different synthetic constructs, we will drive simple cell shape changes (i.e., furrowing) or complex cell shape changes (i.e., gastrulation), allowing us to test basic ideas about cell shape control. In addition, by iteratively combining experiments with computational modeling, it will be possible to develop both a quantitative, mechanistic understanding of processes such as cell division and morphogenesis.