CONTROL OF FLOOR PLATE INDUCTION BY AXIAL MESODERM

本提案所述实验的目的是 阐明细胞和分子事件的诱导下， 脊索旁的地板 地板是一套专门的 位于胚胎腹侧中线的神经上皮细胞 脊髓 地板似乎是造成 腹侧脊髓内神经元的分化和组织 在发展的后期阶段， 脊髓内的轴突。 我们之前已经证明， 特异性的功能和抗原特性的差异， 底板取决于来自下层的感应信号 脊索 这里描述的实验使用简单的测定系统， 测量细胞中底板特异性基因表达的诱导， 外侧神经板通常不会形成底板。 该测定将用于检查发育表达模式， 脊索衍生信号的生物化学性质，并作为一种检测 方法在活动的识别。 我们将使用一个表达式 克隆方法来鉴定编码底板诱导的cDNA 活动 从长远来看，我们的目标是通过以下方式了解这些机制： 哪些神经上皮细胞对脊索信号作出反应， 地板差异化的方案。 脊索地板诱导信号的识别及 阐明其作用机制将是一个重要步骤， 对早期诱导过程和分化过程的理解 和早期神经管的组织。

The goal of the experiments to be described in this proposal is to elucidate the cellular and molecular events underlying the induction of the floor plate by the notochord. The floor plate is a specialized set of neuroepithelial cells located at the ventral midline of the embryonic spinal cord. The floor plate appears to be responsible for the differentiation and organization of neurons within the ventral spinal cord and, at later stages of development, plays a pivotal role in the guidance of axons within the spinal cord. We have previously shown that the differentiation of functional and antigenic properties that are specific to the floor plate is dependent on an inductive signal from the underlying notochord. The experiments described here use a simple assay system to measure the induction of floor plate-specific gene expression in cells of the lateral neural plate that would not normally give rise to floor plate. This assay will be used to examine the developmental expression pattern and biochemical properties of the notochord-derived signal and as a detection method in the identification of the activity. We will use an expression cloning approach to identify cDNAs that encode the floor plate-inducing activity. In the longer term, the goal is to understand the mechanisms by which neuroepithelial cells respond to the notochordal signal and initiate a program of floor plate differentiation. The identification of a notochord-derived floor plate-inducing signal and the elucidation of its mechanisms of action will be an important step in the understanding of early inductive processes and in the differentiation and organization of the early neural tube.