The cellular basis of morphogenetic differences between ectoderm and mesoderm

为了建立一个成熟的有机体，胚胎的不同部分逐渐发展出不同的特性。最重要的区别之一是，将建立“屏障”的细胞群，如皮肤、肠壁或血管，与那些将更多地孤立迁移以填充这些屏障之间的空间的细胞之间的区别，这些细胞稍后将从那里形成肌肉、肌腱或连接。这些不同细胞的两个主要方面与细胞黏附(第一组高得多)和迁移(第二组高得多)相对应。这些差异很早就出现了，当时胚胎还是一大堆未分化的细胞：第一次分离产生了一种名为外胚层的胚胎组织，这是屏障细胞层的原型，而中胚层是一种典型的迁移细胞群体。这是研究这一过程的理想阶段，因为这个系统比成年生物体简单得多。我们假设，由几个调控蛋白组成的简单网络控制着这些基本特征。我们建议使用青蛙胚胎来识别这些小网络或模块。我们将使用一种涉及一系列现代技术的多学科方法，包括高分辨率实时荧光显微镜，对两个单独分离的细胞之间的力进行物理测量，以及使用一种名为蛋白质组学的技术完全识别细胞表面的所有蛋白质成分。这个项目应该对从水母到昆虫和人类的所有动物生物共同的非常基本和基本的细胞特性有重要的新见解。

To build an adult organism, different parts of embryos progressively develop distinct properties. One of the most important differences is between the cell populations that will build “barriers”, such as the skin, the gut wall, or the blood vessels, and the cells that will migrate more in isolation to populate the space between these barriers , where they will later from for example muscles, tendons, or joins. Two major aspects of these different cells correspond cell adhesion (much higher in the first group) and to migration (much higher in the second group). These differences appear very early, when the embryo is still a rough mass of undifferentiated cells: the first separation produces an embryonic tissue called the ectoderm, which is the prototype of a barrier cell layer, and the mesoderm, a typical migratory cell population. This is an ideal stage to study this processes, because the system is much simpler than in an adult organism. We hypothesize that simple networks of a few regulatory proteins control these essential characteristics. We propose to use the frog embryo to identify these small networks, or modules. We will use a multidisciplinary approach involving a whole range of modern techniques, including high resolution live fluorescence microscopy, physical measurement of forces between two single isolated cells, and complete identification of all protein components of the cell surface using a technique called proteomics. This project should important new insights in very basic and essential cell properties common to all animal organisms, from jellyfish to insects and humans.