MOLECULAR REGULATION OF EARLY XENOPUS DEVELOPMENT

非洲爪蟾早期发育的分子调控

• 批准号: 2673623
• 负责人: David Kimelman
• 金额: $ 20.77万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2673623
• 关键词: Xenopus; alternatives to animals in research; biological signal transduction; cadherins; cell cell interaction; density gradient ultracentrifugation; developmental genetics; early embryonic stage; fibroblast growth factor; gap junctions; genetic regulation; genetic transcription; growth factor receptors; histogenesis; immunoprecipitation; mesoderm; messenger RNA; nonmammalian vertebrate embryology; polymerase chain reaction; protein kinase; protein structure function; transcription factor

Development of the vertebrate embryo depends on intercellular signaling to specify the fate of cells comprising the embryonic body. Although many of the intercellular inducing factors involved in these signaling events have now been identified (e.g. FCF, Vg1, Xwnt, noggin), it is not known how intracellular signals triggered by these factors mediate cell fate. Toward this end, we have isolated a SER/THR kinase, Xgsk-3, from the amphibian, Xenopus laevis. Inhibition of Xgsk-3 activity on the ventral side of the embryo with a dominant-negative mutant of Xgsk-3, leads to embryos with completely twinned axes, including secondary heads. This result indicates that Xgsk-3 actively represses axis formation in the early embryo, and that axal development requires the repression of Xgsk-3 activity within the future Spemann organizer, establishing Xgsk-3 as a major intracellular regulator of early axis formation in the Xenopus embryo. In addition, genetic evidence from DrosophiLa, together with localization of the Xgsk-3 gene in Xenopus, suggests that it may also be an important regulator of the neuroectoderm. Three major areas will be pursued: 1. The regulation of Xgsk-3 in early axial patterning will be investigated, by developing biochemical assays for Xgsk-3 function. These experiments will determine which inducing factors have the ability to regulate Xgsk-3, and will ultimately elucidate the mechanism for Xgsk-3 inhibition during early development 2. The role of Xgsk-3 in later axial development and neural development will be determined, using the dominant-negative mutant of Xgsk-3 to block its function during different stages of embryogenesis. 3. A search for the proteins that regulate Xgsk-3 and that are regulated by Xgsk-3 during different developmental stages will be conducted in order to elucidate the intracellular signaling pathway that regulates axis development in the Xenopus embryo. The ultimate goal of this proposal is to provide a dear mechanistic understanding of the intracellular signaling processes that underlie vertebrate embryonic development. Since birth defects are due to a failure in the normal processes of embryogenesis, these studies will delineate the processes that can be perturbed by dysmorphogenic agents and genetic abnormalities.

脊椎动物胚胎的发育取决于细胞间信号传导 确定构成胚胎体的细胞的命运。 虽然 许多细胞间诱导因子参与这些信号传导 事件现已确定（例如 FCF、Vg1、Xwnt、noggin），但尚未确定 知道这些因素触发的细胞内信号如何介导细胞 命运。 为此，我们从其中分离出了一种 SER/THR 激酶 Xgsk-3 两栖动物，非洲爪蟾。 Xgsk-3 活性的抑制 胚胎腹侧带有 Xgsk-3 显性失活突变体， 导致胚胎具有完全孪生的轴，包括次生头。 该结果表明 Xgsk-3 主动抑制轴形成 早期胚胎，轴发育需要抑制 未来 Spemann 组织者内的 Xgsk-3 活动，建立 Xgsk-3 作为非洲爪蟾早期轴形成的主要细胞内调节剂 胚胎。 此外，来自果蝇的遗传证据，以及 Xgsk-3 基因在爪蟾中的定位表明它也可能是 神经外胚层的重要调节因子。 三大领域将 追求： 1. Xgsk-3在早期轴向图案化中的调节将是 通过开发 Xgsk-3 功能的生化检测方法进行研究。这些 实验将确定哪些诱导因素能够 调控Xgsk-3，并最终阐明Xgsk-3的机制 早期发育过程中的抑制 2. Xgsk-3 在后期轴发育中的作用 发育和神经发育将被确定，使用 Xgsk-3 的显性失活突变体在不同时期阻断其功能 胚胎发生的阶段。 3. 寻找调节蛋白质 Xgsk-3 以及在不同发育过程中受 Xgsk-3 调节的 将进行阶段以阐明细胞内 调节非洲爪蟾胚胎轴发育的信号通路。 该提案的最终目标是提供一种亲爱的机制 了解细胞内信号传导过程的基础 脊椎动物胚胎发育。 由于出生缺陷是由于 胚胎发生的正常过程失败，这些研究将 描述可能被变形剂扰乱的过程 和遗传异常。