MOLECULAR REGULATION OF EARLY XENOPUS DEVELOPMENT

脊椎动物胚胎的发育依赖于一个称为 诱导，其中细胞间的通信被用来指定 构成胚胎体平面的细胞的精确组织。 两 生长因子最近已被确定为这些的可能调节剂， 感应事件 这项建议特别着重于下列机构之一的作用： 这些，碱性成纤维细胞生长因子（bFGF），因为它都诱导 中胚层细胞类型的形成，存在于早期胚胎中。 bFGF介导的中胚层诱导的三个方面将继续进行。 1. 为了确定中胚层是如何在一个有限的区域内形成图案的 在早期胚胎中，bFGF蛋白将被定位。 作为中胚层 相反，诱导可以通过调节bFGF的分泌来控制， 将研究bFGF从早期卵裂球的释放。 最后 bFGF在胚胎中的功能将被抑制，以确定其在胚胎发育中的作用。 在诱导过程中的体内作用。 2. 新的发现是卵母细胞含有反义mRNA， 导致bFGF转录物的共价修饰将进一步 调查以确定这种修饰是否是机制的一部分 bFGF转录物的靶向降解。 此外，蛋白质 将广泛地表征由反义转录物编码的基因。 3. 由于很少有人知道细胞对bFGF的反应， 中胚层的诱导，响应于 将分离bFGF。 在诱导期早期转录的基因 过程或中胚层的特定部分将首先进行研究， 长期目标是定义基因变化的层次 由bFGF发起。 由于出生缺陷是由于胚胎发生机制的失败， 重要的是要了解正常的发展途径。 以来 bFGF不仅参与发育调控，而且还能转化成 不同医学领域的共同问题。

Development of the vertebrate embryo is dependent on a process termed induction in which intercellular communication is utilized to specify the precise organization of the cells comprising the embryonic body plan. Two growth factors have been recently identified as likely regulators of these inductive events. This proposal focuses specifically on the role of one of these, basic fibroblast growth factor (bFGF), as it both induces the formation of mesodermal cell types and is present in the early embryo. Three aspects of bFGF-mediated mesoderm induction will be pursued. 1. In order to determine how mesoderm is patterned in a restricted region of the early embryo, the bFGF protein will be localized. As mesoderm induction may instead be controlled by the regulated secretion of bFGF, the release of bFGF from the early blastomeres will be studied. Finally, the function of bFGF in the embryo will be inhibited in order to define its in vivo role in the inductive process. 2. The novel finding that the oocyte contains an anti-sense mRNA that causes the covalent modification of the bFGF transcript will be further investigated to determine whether this modification is part of a mechanism of targeted degradation of the bFGF transcript. In addition, the protein encoded by the anti-sense transcript will be extensively characterized. 3. As little is known about the cellular response to bFGF during the induction of mesoderm, cDNA copies of the RNAs expressed in response to bFGF will be isolated. Genes that are transcribed early in the inductive process or in a particular part of the mesoderm will be studied initially, with a long range goal of defining the hierarchy of genetic changes initiated by bFGF. As birth defects arise from a failure in the mechanisms of embryogenesis, it is important to understand the normal pathway of development. Since bFGF s not only involved in development regulation but can also convert common issues in different medical fields.