Body Plan Formation in Early Mouse Embryo

描述：(摘自申请者摘要)基本架构 动物的身体是在胚胎发育的早期建立起来的。与其他 脊椎动物系统，对哺乳动物的卵子如何创造基本的 身体计划。这项研究的主要目的是阐明分子 决定细胞命运和体轴形成的机制 小鼠胚胎。这项研究的第一个具体目标是确定 卵子中的细胞质和细胞膜成分，参与 内细胞团(ICM)和滋养层(TE)的形成。形成 ICM和TE是小鼠发育过程中第一次细胞分化事件。我们 将使用谱系特异的分子标记来鉴定 用不同的血管紧张素转换酶抑制剂处理的胚胎中的这两种不同的细胞类型 细胞骨架、膜转运和细胞黏附。我们还将调查 卵细胞胞质成分在ICM和TE发育中的作用。为了这个 研究，我们将利用离心技术，这些技术已经被 成功地用于鉴定卵子中的发育重要因素 其他脊椎动物和脊索动物。第二个目的是分析网络的功能 卵子中定位的分子，即STAT3和瘦素蛋白。因为这两个 STAT3和瘦素在许多细胞中作为细胞分化和生长的调节因子 系统，我们假设STAT3和瘦素在体内的局部分布 鸡蛋在制定身体计划中起着重要的作用。我们会 通过在小鼠卵子中过度表达STAT3和瘦素来检验这一假设 扰乱它们的正态分布。我们还将使用构成主动和 STAT3的显性否定结构来考察局部化的 更详细的STAT3。第三个目标是确定Wnt/b-连接蛋白的作用 胚胎体轴形成中的信号通路。尽管这些信号 小鼠胚胎中轴的形成可能通过多种途径参与，其 作用模式不像其他脊椎动物系统那样清晰，特别是 青蛙。我们将确定Wnt/b-catenin信号通路在 通过引入抑制性结构来更详细地形成小鼠轴 信号通路，并在早期通过局部激活信号通路 胚胎。本申请中提出的研究应使我们能够更好地 了解最早危急事件的分子机制 哺乳动物的身体计划形成，并为解决许多问题提供线索 与人类先天缺陷以及生物医学技术有关。

DESCRIPTION: (Scanned from the applicant's abstract) The basic architecture of animal bodies is established during early embryogenesis. Compared to other vertebrate systems, little is known about how a mammalian egg creates the basic body plan. The major goal of this study is to elucidate the molecular mechanisms responsible for cell fate determination and body axis formation in the mouse embryo. The first specific aim of this study is to identify cytoplasmic and membrane components in the egg that are involved in the formation of the inner cell mass (ICM) and the trophectoderm (TE). Formation of the ICM and TE is the first cell differentiation event in mouse development. We will use lineage-specific molecular markers to identify the differentiation of these two distinct cell types in embryos treated with various inhibitors of the cytoskeleton, membrane trafficking and cell adhesion. We will also investigate the role of egg cytoplasmic components in the ICM and TE development. For this study, we will exploit the centrifugation techniques, which have been successfully used to identify developmentally important factors in the egg of other vertebrates and chordates. The second aim is to analyze the function of localized molecules in the egg, namely Stat3 and Leptin proteins. Since both Stat3 and Leptin act as regulators of cell differentiation and growth in many systems, we hypothesize that the localized distribution of Stat3 and Leptin in the egg plays an important role in the establishment of the body plan. We will test this hypothesis by overexpressing Stat3 and Leptin in the mouse egg to disturb their normal distribution. We will also use constitutive active and dominant negative constructs of Stat3 to examine the function of the localized Stat3 in more detail. The third aim is to define the role of the Wnt/b-catenin signaling pathway in body axis formation in the embryo. Although the signaling pathway is suggested to be involved in axis formation in the mouse embryo, its mode of action is not as clear as in other vertebrate systems, specifically the frog. We will define the role of the Wnt/b-catenin signaling pathway in the mouse axis formation in more detail by introducing inhibitory constructs of the signaling pathway, and by locally activating the signaling pathway in early embryos. The studies proposed in this application should enable us to better understand the molecular mechanisms of the earliest critical events in mammalian body plan formation, and provide clues to resolve many problems associated with human birth defects as well as biomedical technology.