Mechanisms of cell coordination in epithelial morphogenesis analyzed by quantitative 3D imaging

在胚胎发育和组织修复期间，细胞会长距离移动并经历戏剧性的形状变化，在这样做的过程中，它们会推动、拉动和变形邻居。因此，当细胞移动或产生物理作用力时，为了保持组织的完整性，精致的协调程度是必要的。尽管参与力量产生的主要分子参与者已知，但细胞协调其行为的机制仍然是个谜，主要是因为很难确定触发细胞共同行动的初始事件。值得注意的是，许多不同物种的胚胎的伤口愈合是由邻近伤口的细胞协调产生的力驱动的。在伤口愈合过程中，人们可以随意地清楚地建立和传递诱导细胞协调的信号(伤口)，使其成为研究协调力量产生机制的理想系统。我们建议以果蝇胚胎创伤修复为模型系统，研究细胞协调的物理和分子机制。我们将通过三个项目来实现这一点，在这些项目中，我们将利用果蝇可用的强大的实时成像和遗传工具，以及我们以前开发定量图像分析工具和生物物理方法来局部操纵胚胎中的力的经验。这项研究计划将在加拿大率先建立和应用生物物理方法，包括磁镊子或激光消融，用于活体生物，以及创造新的高通量、基于显微镜的筛查工具，将对其他研究人员有用。完成这些目标还将有助于为3名博士生和几名暑期学生提供图像分析、生物物理学、细胞和发育生物学领域的培训。目前，加拿大学术界和工业界(生物技术、制药、软件工程)对具有这种多学科背景的实习生的需求很高。

During embryonic development and tissue repair, cells move over long distances and undergo dramatic changes in shape, and in so doing, they push, pull and deform their neighbors. Therefore, an exquisite degree of coordination is necessary to preserve the integrity of tissues when cells move or generate physical forces. Although the main molecular players involved in force generation are known, the mechanisms by which cells coordinate their behaviors remain a mystery, mainly because it is difficult to establish the initial events that trigger cells to act together. Notably, wound healing in embryos of many different species is driven by the coordinated generation of force by the cells adjacent to the wound. In wound healing one can clearly establish and deliver at will the signal that induces cell coordination (the wound), making it an ideal system to investigate the mechanisms of coordinated force generation. We propose to investigate the physical and molecular mechanisms of cell coordination using wound repair in Drosophila embryos as a model system. We will do these through 3 projects in which we will take advantage of the powerful live imaging and genetic tools available in Drosophila, and of our previous experience developing quantitative image analysis tools and biophysical methods to locally manipulate forces in embryos. This research program will be pioneer in Canada in the establishment and application of biophysical methods, including magnetic tweezers or laser ablation, for their use in living organisms, as well as in the creation of new of tools for high-throughput, microscopy-based screening that will be of use to other researchers. Completing these aims will also serve the purpose of providing 3 Ph.D. students and several summer students with training in the areas of image analysis, biophysics, and cell and developmental biology. Trainees with this multidisciplinary background are currently in high demand in Canada, both in academia and in industry (biotech, pharmaceutical, software engineering).