Combinatorial signaling in zebrafish development

描述(申请人提供)：细胞间信令发挥作用 在胚胎发育模式和细胞调控中的关键作用 胚胎和成体的增殖和存活。通过在时间和空间上 结合来自不同信号通路的信号，有机体获得了 通过激活目标基因来产生复杂的细胞决策 对多种信号因素作出反应。这些组合信号是如何 在分子和细胞水平上的使用在很大程度上是不好的 明白了。这项提议的核心问题是：BMPS和WNTS是如何工作的 共同建立遗传等级，从而形成 后中胚层和神经脊？要检查这一点，有三个途径 使用斑马鱼作为模型系统来追求。(1)转基因斑马鱼表达 热休克控制下的BMP和WNT/B-连环蛋白激活剂和抑制剂将 用于确定何时以及如何使用这些信号来调节 在整个发育过程中形成后中胚层和神经脊。 (2)几个关键靶基因的启动子对BMP和 将对WNT/B-连环蛋白信号进行分析，以了解这些信号是如何 信号通路最终是在转录水平上整合的。(3) 微阵列和消减筛选将被用来识别 受BMP和Wnt/B-catenin信号的调节使用斑马鱼突变体 BMP和Wnt信号通路存在缺陷。精心挑选的子集 在这些基因中，表达在后中胚层和神经脊中， 将被选中进行进一步研究，使用转基因鱼的组合 表达可诱导的BMP和Wnt激活物和抑制物，过表达 吗啉反义寡核苷酸的研究。最后，这一分析将 提供了一个分子框架，用于理解BMP和WNT如何组合 信号导致胚胎内特定组织的形成。因为这两个 BMP和Wnt信号参与人类的疾病过程，而且自从 这些信号通路是高度保守的，这项研究将直接 与理解人类疾病机制的相关性。

DESCRIPTION (provided by applicant): Intercellular signaling plays a critical role in patterning embryonic development and in the regulation of cell proliferation and survival in embryos and adults. By temporally and spatially combining signals from different signaling pathways, organisms gain the ability to produce complex cellular decisions through the activation of target genes that respond to multiple signaling factors. How these combinatorial signals are used at the molecular and cellular level is for the most part not well understood. The central question of this proposal is: how do Bmps and Wnts work together to establish genetic hierarchies leading to the formation of the posterior mesoderm and neural crest? To examine this, three avenues will be pursued using zebrafish as a model system. (1) Transgenic zebrafish expressing Bmp and Wnt/B-catenin activators and inhibitors under heat shock control will be used to determine when and how these signals are used to regulate the formation of the posterior mesoderm and neural crest throughout development. (2) The promoters of several key target genes responding to Bmp and Wnt/B-catenin signals will be analyzed in order to understand how these signaling pathways are ultimately integrated at the transcriptional level. (3) Microarray and subtractive screens will be used to identify genes that are regulated by both Bmp and Wnt/B-catenin signals using zebrafish mutants that have defects in the Bmp and Wnt signaling pathways. A critically chosen subset of these genes, which are expressed in the posterior mesoderm and neural crest, will be selected for further study using a combination of the transgenic fish expressing inducible Bmp and Wnt activators and inhibitors, overexpression studies and morpholino antisense oligonucleotides. Finally, this analysis will provide a molecular framework for understanding how combinatorial Bmp and Wnt signals lead to the formation of specific tissues within the embryo. Since both Bmp and Wnt signaling are involved in disease processes in humans, and since these signaling pathways are highly conserved, this research will have direct relevance to understanding mechanisms of human disease.