Morphogenetic mechanisms regulating directed cell migration required to form the vertebrate posterior body

调节形成脊椎动物后体所需的定向细胞迁移的形态发生机制

• 批准号: 9403120
• 负责人: David Kimelman
• 金额: $ 33.13万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9403120
• 关键词: Adopted; Anterior; Biological Assay; Biological Models; Cell Proliferation; Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Congenital Abnormality; Development; Down-Regulation; Embryo; Embryo Deaths; Failure; Gene Expression; Goals; Growth; Homeobox Genes; Individual; Lead; Measures; Mesoderm; Mesoderm Cell; Movement; Muscle; Neural tube; Neurons; Population; Process; Regulator Genes; Resolution; Somites; Spinal Cord; Stem cells; System; Testing; Time; Transgenic Organisms; Zebrafish; base; cell motility; cell type; cellular imaging; directional cell; epithelial to mesenchymal transition; high resolution imaging; in vivo; in vivo imaging; innovation; insight; loss of function; migration; mutant; novel; prevent; progenitor; relating to nervous system; rho; somitogenesis

PROJECT SUMMARY Much of the vertebrate embryonic body forms from a recently discovered neuromesodermal progenitor cell population located at the most posterior end of the early embryo, in a region called the Progenitor Zone (PZ). The PZ gradually releases mesodermal cells that populate the somites (primarily muscle) as well as the neural cells that form the spinal cord, until the complete anterior-posterior axis of the embryo has been established. While the mechanisms controlling the differentiation of the neuromesodermal cells are increasingly understood, how these cells regulate the completion of the epithelial to mesenchymal transition (EMT) and directional migration from the PZ into the body largely remains a mystery, yet this process is essential for the embryo to form its anterior-posterior axis correctly. Based on our analysis of a zebrafish mutant that specifically disrupts the migration of mesodermal cells from the PZ, we have identified a unique set of PZ-expressed Progenitor Cytoskeletal Regulatory Genes (PCRGs) that we propose must be down-regulated for cells to complete the EMT and migrate from the PZ into the presomitic mesoderm (PSM). Using a novel explant assay we recently developed that allows in vivo imaging of the migrating cells at very high resolution, in Aim 1 we will determine how the PCRGs are used to regulate the directional movement of cells into the PSM using a combination of gain and loss of function studies, as well as examining how the PCRGs control Rho activity. In Aim 2 we will determine how the posterior hox genes, which through unknown mechanisms control the orderly movement of cells from the PZ into the embryonic body, specifically regulate cell movements using our novel explant system to examine directional cell migration and protrusive activity of the hox-expressing cells. We will test the hypothesis that the hox genes act to sustain the expression of the PCRGs, and thereby regulate the timing of cell entry into the PSM. Collectively, these studies will examine the premise that the migration of cells from the PZ into the PSM is regulated by the action of the PCRGs and posterior hox genes, which acting together control the orderly anteriorward migration of newly differentiating mesodermal cells, thus allowing the vertebrate embryonic body to form with remarkable fidelity. With the ease of making transgenic lines that allow temporally controlled expression of the PCRGs and hox genes as well as CRISPR mutant lines, combined with our innovative explant system for high resolution imaging, zebrafish is an excellent system for understanding the mechanisms that control the early formation of the vertebrate body.

项目摘要 来自最近发现的神经溶性祖细胞的大部分脊椎动物胚胎体形成 种群位于早期胚胎的后端最大的端，位于一个名为祖细胞区域（PZ）的区域。 PZ逐渐释放出填充物体（主要是肌肉）的中胚层细胞以及神经 形成脊髓的细胞，直到已经建立了胚胎的完整前轴。 而控制神经抑制细胞的分化的机制越来越多 理解，这些细胞如何调节上皮到间充质转变（EMT）的完成和 定向从PZ迁移到体内，在很大程度上仍然是一个谜，但是这个过程对于 胚胎正确形成其前后轴。 基于我们对斑马鱼突变体的分析，该突变体专门破坏了中胚层细胞的迁移 PZ，我们已经确定了一组独特的PZ表达祖细胞骨骼调节基因（PCRGS） 我们建议必须下调细胞才能完成EMT并从PZ迁移到 前中胚层（PSM）。使用新型的外植体测定法，我们最近开发了该测定法 在非常高的分辨率的迁移细胞中，在AIM 1中，我们将确定如何使用PCRG来调节 使用增益和功能研究丧失的组合以及功能研究的组合以及 检查PCRG如何控制RHO活性。 在AIM 2中，我们将确定如何通过未知机制控制的后HOX基因 细胞从PZ有序地运动到胚胎体，特异性地调节细胞运动 我们的新型外植体系统，以检查表达HOX的定向细胞迁移和突出活性 细胞。我们将检验以下假设，即HOX基因作用以维持PCRG的表达，从而 调节细胞进入PSM的时间。 总的来说，这些研究将研究以下前提：细胞从PZ迁移到PSM的前提 由PCRG和后HOX基因的作用调节，它们共同控制有序 新分化的中胚层细胞的前向迁移，从而允许脊椎动物胚胎 身体以非凡的忠诚形成。易于制作转基因线，允许暂时 PCRG和HOX基因以及CRISPR突变型线的控制表达，并结合我们 斑马鱼是用于高分辨率成像的创新外植体系统，是理解的绝佳系统 控制脊椎动物早期形成的机制。