Cell polarity and morphogenesis in Xenopus embryos

项目摘要 在早期脊椎动物胚胎中，信号通路指导细胞命运并协调 形态发生运动，将细胞放置到适当的位置，以经历新一轮的 信号和命运规范和形态发生的新浪潮。一个长期存在的问题 细胞极性的变化如何决定早期发育过程中的集体细胞行为。 为了解决这个问题，该计划的重点是核心平面细胞极性（PCP）途径， 是脊椎动物形态发生过程的主要驱动力之一。核心PCP蛋白具有 是在果蝇遗传学研究中发现的在脊椎动物中，五氯苯酚蛋白复合物 Vangl/Pk/Celsr和Fz/Dvl/Celsr是保守的，并沿着沿着细胞的相对细胞边缘积累。 体轴，标记组织极性。PCP核心蛋白的重要性远远超出了 作为上皮极性标记物，因为它们的脊椎动物同系物在关键发育中起作用， 过程，包括原肠胚形成运动，神经管关闭和分支形态发生， 功能性纤毛和左右图案的形成。获得…的机械知识 形态发生事件，包括脊椎动物原肠胚形成，我们将研究以下长期存在的 该领域的问题：a）细胞如何响应线索，B）细胞极性如何转换 空间限制性激活效应物，如肌球蛋白II，和c）如何肌动球蛋白收缩 并且所产生的机械力改变细胞形状并协调集体细胞运动。 新的力依赖的基因，参与控制形态发生将被确定。 这些方向将采用高分辨率成像，胚胎学和分子生物学 生物技术结合系统水平分析（蛋白质组学和转录组学）。我们 研究将使用非洲爪蟾胚胎作为我们的主要实验模型，由于其快速的外部 开发，易于实验操作和大尺寸允许生化和系统 生物学方法。这些研究将促进基础细胞生物学的知识 脊椎动物形态发生的潜在机制。与人类健康的高度相关性是由于 已知PCP信号传导与多种先天性缺陷和综合征、多囊 肾脏疾病和癌症。

Project summary In the early vertebrate embryo, signaling pathways instruct cell fates and orchestrate morphogenetic movements, placing cells into proper positions to experience new rounds of signaling and new waves of fate specification and morphogenesis. A long standing question remains how changes in cell polarity determine collective cell behaviors during early development. To approach this problem, this program focuses on the core planar cell polarity (PCP) pathway that is one of the main drivers of morphogenetic processes in vertebrates. Core PCP proteins have been discovered in Drosophila genetic studies. In vertebrates, the PCP protein complexes Vangl/Pk/Celsr and Fz/Dvl/Celsr are conserved and accumulate at opposite cell edges along the body axis, marking tissue polarity. The significance of the core PCP proteins extends far beyond being epithelial polarity markers, as their vertebrate homologs function in key developmental processes, including gastrulation movements, neural tube closure and branching morphogenesis, the formation of functional cilia and left-right patterning. To gain mechanistic knowledge of morphogenetic events, including vertebrate gastrulation, we will study the following long-standing questions in the field: a) how cells polarize in response to a cue, b) how the cell polarity translates into spatially restricted activation of effectors such as Myosin II, and c) how actomyosin contractions and the resulting mechanical forces alter cell shape and coordinate collective cell movements. New force-dependent genes that are involved in the control of morphogenesis will be identified. These directions will be pursued using high resolution imaging, embryological and molecular biological techniques combined with systems level analysis (proteomics and transcriptomics). Our studies will use Xenopus embryos as our main experimental model, due to their fast external development, ease of experimental manipulation and large size allowing biochemical and systems biology approaches. The proposed studies will advance the knowledge of basic cell biological mechanisms underlying vertebrate morphogenesis. High relevance to human health is due to the known connections of PCP signaling to multiple congenital defects and syndromes, polycystic kidney disease and cancers.