Control of Cell Movements During Gastrulation in Xenopus

非洲爪蟾原肠胚形成过程中细胞运动的控制

• 批准号: 0315767
• 负责人: Jeffrey Miller
• 金额: $ 36万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0315767&HistoricalAwards=false
• 关键词: Control; Cell; Movements; During; Gastrulation

0315767MillerThe control of morphogenetic movements during gastrulation is critical for the viability of the organism and, therefore, determining the molecular pathways that regulate cell activities during gastrulation is of fundamental importance. Recent work from Xenopus and zebrafish provide evidence that polarized cell motility and shape changes during gastrulation are regulated by the Wnt/PCP pathway. These studies have defined a critical role for the signaling protein Dishevelled (Dsh) and suggest that Dsh controls cell polarity through regulation of the actin cytoskeleton. Preliminary studies from Dr. Miller's laboratory provide support for the hypothesis that the signaling protein Eps8 interacts with Dsh providing a potential link between extracellular signals and the actin cytoskeleton during gastrulation. The objective of the current research project is to determine the mechanisms by which Eps8 controls morphogenetic movements during gastrulation, using embryos of the clawed frog, Xenopus laevis, as a model system. This proposal will seek to answer the following questions: (1) What is the requirement for Eps8 during development? The function of Eps8 in Xenopus development will be investigated using gene-knockdown strategies and expression of dominant-negative forms of Eps8. The resulting phenotypes will be examined using morphological, histological, and gene expression analyses. (2) What morphogenetic events does Eps8 regulate during gastrulation? Gain- and loss-of-function approaches will be combined with a detailed analysis of (i) cell polarity, shape, and protrusive activity, (ii) actin organization, and (iii) cell-cell adhesion to investigate the mechanism by which Eps8 regulates morphogenesis. They will also characterize the subcellular distribution of Eps8 during gastrulation. (3) What signals regulate Eps8 function during gastrulation? They will utilize biochemical and cell biological assays to examine whether Eps8 function and/or its interaction with Dsh is regulated by PDGF or Wnt signals. Broader impact of the proposed research: By exploiting their expertise in using classical embryological approaches and modern imaging tools for the analysis of cell movements and protein localization in vivo, the Miller laboratory will gain important insights into the mechanisms that control morphogenetic movements during gastrulation in vertebrates. Since convergent extension movements are a fundamental process employed throughout the animal kingdom, their studies in Xenopus will lead to a greater understanding of the how cell movements are coordinated to control tissue patterning in other systems. In addition, a graduate student, and an undergraduate student will work extensively on this project. They will receive extensive training in microscopy, biochemistry, experimental embryology, and cell biology as part of this project.

0315767米勒在原肠胚形成过程中形态发生运动的控制是至关重要的生物体的生存能力，因此，确定在原肠胚形成过程中调节细胞活动的分子途径是至关重要的。 非洲爪蟾和斑马鱼最近的工作提供的证据表明，在原肠胚形成过程中的极化细胞运动和形状的变化是由Wnt/PCP途径调节。 这些研究已经确定了一个关键的作用，为信号蛋白Dishevelled（Dsh），并建议Dsh控制细胞极性通过调节肌动蛋白细胞骨架。 米勒博士实验室的初步研究为以下假设提供了支持：信号蛋白Eps 8与Dsh相互作用，在原肠胚形成期间提供了细胞外信号与肌动蛋白细胞骨架之间的潜在联系。 目前的研究项目的目的是确定的机制，Eps 8控制原肠胚形成过程中的形态发生运动，使用爪蛙，非洲爪蟾，作为一个模型系统的胚胎。 本提案将寻求回答以下问题：（1）在开发过程中对EPS 8的要求是什么？ Eps 8在非洲爪蟾发育中的功能将使用基因敲低策略和显性负性形式的Eps 8的表达进行研究。 将使用形态学、组织学和基因表达分析检查所得表型。 (2)Eps 8在原肠胚形成过程中调节哪些形态发生事件？ 功能获得和功能丧失的方法将与（i）细胞极性，形状和细胞分裂活性，（ii）肌动蛋白组织和（iii）细胞-细胞粘附的详细分析相结合，以研究Eps 8调节形态发生的机制。 他们还将表征原肠形成期间Eps 8的亚细胞分布。 (3)在原肠胚形成过程中，哪些信号调节Eps 8的功能？他们将利用生物化学和细胞生物学测定来检查Eps 8功能和/或其与Dsh的相互作用是否受PDGF或Wnt信号的调节。 拟议研究的更广泛影响：通过利用他们在使用经典胚胎学方法和现代成像工具分析体内细胞运动和蛋白质定位方面的专业知识，米勒实验室将获得对脊椎动物原肠胚形成过程中控制形态发生运动的机制的重要见解。 由于收敛延伸运动是整个动物王国采用的基本过程，他们在非洲爪蟾的研究将导致对细胞运动如何协调以控制其他系统中的组织图案的更好理解。 此外，一名研究生和一名本科生将在这个项目上进行广泛的工作。 作为该项目的一部分，他们将接受显微镜、生物化学、实验胚胎学和细胞生物学方面的广泛培训。