The dual role of the extracellular matrix in inter-tissue adhesion and tissue movement

项目摘要 该提案的总体目标是确定细胞外基质（ECM）如何有助于 体内三维组织的形态发生。ECM在细胞迁移领域得到了很好的研究; 然而，分析ECM在其他发展背景中的作用的例子有限。了解 ECM在开发过程中的作用，一个可以跟踪ECM的三维系统， 需要在开发期间在体内定量和操作。斑马鱼的神经管正在伸长， 非常适合于在三维组织形态发生期间检查ECM，由于易于成像， 量化纤连蛋白基质重塑的能力，以及许多可用的突变体和工具， 斑马鱼操纵纤连蛋白基质和组织力学。在该系统中，存在纤连蛋白 两个组织，前体中胚层（PSM）和神经管之间。纤连蛋白作为一种胶水， 两个组织结合在一起，并且是沿着中-外侧轴适当的神经管会聚所需要的。然而，在这方面， 神经管也相对于PSM和纤连蛋白基质向后移动。当主要整合素 当将细胞与纤连蛋白基质结合的受体被去除时， 在神经管中观察到。此外，当去除纤连蛋白时，神经管完全伸长。 总之，这些数据表明，细胞迁移沿着纤连蛋白基质是不需要的后方 神经管的运动。总的来说，这表明神经管通过一个 除了细胞沿着纤连蛋白基质沿着迁移之外， 纤连蛋白基质。这种情况如何发生的一个模型是通过神经细胞中整合素动力学的变化， 管，其中整合素活化和稳定性的降低可以允许组织水平运动，同时仍然 保持粘附性。在目的1中，我将研究整合素结合动力学的背景下，后 神经管的运动使用技术，包括FRET/FLIM，抗体染色和实时成像， 将产生整联蛋白动力学的跨尺度视图。这些数据将产生新的假设， 整联蛋白有助于神经管运动，这将使用影响神经管后部运动的突变来测试。 神经管和突变，加强或削弱整合素结合活性。在目标2中，我将确定 神经管细胞与ECM的粘附如何影响它们的细胞运动。这将使用 实时跟踪纤连蛋白基质重塑和细胞运动与它们相对于纤连蛋白的位置的关系 矩阵这些数据将产生关于细胞-细胞和细胞-ECM接触如何影响细胞行为的假设， 这将进一步测试使用已建立的突变，影响神经管收敛和改变细胞 粘附和细胞收缩性。

Project Summary The overall goal of the proposal is to determine how the extracellular matrix (ECM) contributes to the morphogenesis of a three-dimensional tissue in vivo. The ECM is well studied in the field of cell migration; however, limited examples exist analyzing the role of the ECM in other developmental contexts. To understand the role of the ECM during development, a three-dimensional system in which the ECM can be tracked, quantified, and manipulated in vivo during development is needed. The elongating neural tube in zebrafish is well-suited to examine the ECM during three-dimensional tissue morphogenesis, due to the ease of imaging, the ability to quantify Fibronectin matrix remodeling, and the numerous mutants and tools that are available in zebrafish to manipulate the Fibronectin matrix and tissue mechanics. In this system, Fibronectin is present between two tissues, the presomitic mesoderm (PSM) and neural tube. Fibronectin acts as a glue to hold the two tissues together and is required for proper neural tube convergence along the medio-lateral axis. However, the neural tube also moves posteriorly in relation to the PSM and Fibronectin matrix. When the main integrin receptor that binds cells to the Fibronectin matrix is removed, no significant changes in cell motion are observed in the neural tube. Furthermore, when Fibronectin is removed, the neural tube elongates fully. Together these data indicate that cell migration along the Fibronectin matrix is not required for posterior movement of the neural tube. Overall, this indicates that the neural tube moves past the PSM through a mechanism other than cell migration along the Fibronectin matrix while also maintaining adhesion to the Fibronectin matrix. One model for how this might occur is through changes in integrin dynamics in the neural tube, in which decreases in integrin activation and stability could allow for tissue level motion while still maintaining adhesion. In aim 1, I will investigate integrin binding dynamics in the context of posterior motion of the neural tube. Using techniques, including FRET/FLIM, antibody staining, and live imaging, a cross-scale view of integrin dynamics will be generated. These data will generate new hypotheses for how integrins contribute to neural tube motion which will be tested using mutations that affect posterior motion of the neural tube and mutations that strengthen or weaken integrin binding activity. In aim 2, I will determine how adhesion of neural tube cells to the ECM influences their cell motion. This will be completed using live tracking of Fibronectin matrix remodeling and cell motion in relation to their position to the Fibronectin matrix. This data will generate hypotheses for how cell-cell and cell-ECM contacts influence cell behavior, which will be further tested using established mutations that affect neural tube convergence and by altering cell adhesion and cell contractility.