Cell Interactions and Cell Fate Specification

细胞相互作用和细胞命运规范

• 批准号: 9817988
• 负责人: Charles Ettensohn
• 金额: $ 36.32万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-15 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817988&HistoricalAwards=false
• 关键词: Cell; Interactions; Fate; Specification

The goal of the proposed research is to elucidate fundamental mechanisms involved in patterning metazoan embryos. Dr. Ettensohn seeks to define the precise roles of specific blastomere interactions in establishing territories of gene expression in the embryo and to elucidate molecular pathways that underlie such interactions. This work also addresses the problem of conditional fate specification- the allocation of cell fates by non-autonomous, context-dependent mechanisms- and the historical problem of embryonic regulation. The model system to be used is the sea urchin, which can be studied using a powerful set of cell and molecular biological tools.Three specific objectives are to be pursued: 1) He will examine the role of Lv-ets, a member of the ets family of transcriptional regulators, in skeletogenic specification during normal development and when novel cell lineages are caused to express a skeletogenic fate by embryo manipulation. He will explore the possibility that Wnt/beta-catenin signaling, which has been shown to regulate skeletogenic specification, does so by altering Lv-ets protein expression and/or localization. 2) Signals from the vegetal region are known to regulate the fates of overlying cells. He will refine our understanding of the role of such signals in patterning through the use of new cell ablation methods, novel cell recombination experiments, and new molecular markers. He will directly test the model that a vegetal-to-animal cascade of signals patterns the early sea urchin embryo. 3) The Wnt/beta-catenin signaling pathway plays an important role in patterning in many organisms. Recent studies have provided strong evidence that components of this pathway are involved in the allocation of cell fates along the animal-vegetal axis of the sea urchin embryo. He will use overexpression of GSK3, C-cadherin, and mutant (activated) beta-catenin mRNAs in combination with embryo manipulation and molecular markers to clarify the role of this pathway in patterning. Dr. Ettensohn will use embryo dissociation studies to test the central question of whether the developmentally programmed pattern of nuclear localization of beta-catenin in the sea urchin (and possibly other metazoan embryos) is dependent on cell-cell signaling, or is regulated by a cell-autonomous mechanism. Finally, he will examine the mechanism by which suppression of the Wnt/beta-catenin pathway blocks skeletogenic specification.

这项拟议的研究的目标是阐明后生动物胚胎图案化的基本机制。Ettensohn博士试图定义特定的卵裂球相互作用在建立胚胎基因表达区域中的确切作用，并阐明这些相互作用背后的分子途径。这项工作还解决了条件命运指定的问题-通过非自主的、上下文相关的机制分配细胞命运-以及胚胎调控的历史问题。将使用的模式系统是海胆，可以使用一套强大的细胞和分子生物学工具进行研究。将追求三个具体目标：1)他将研究ETS转录调控家族成员Lv-ETS在正常发育过程中的骨骼发育规范中的作用，以及当通过胚胎操作使新的细胞谱系表达骨骼发育命运时。他将探索Wnt/β-catenin信号通过改变Lv-ETS蛋白的表达和/或定位来调节骨骼发育规范的可能性。2)已知来自植物区的信号调节上覆细胞的命运。他将通过使用新的细胞消融方法、新的细胞重组实验和新的分子标记来完善我们对这些信号在图案化中的作用的理解。他将直接测试这个模型，即植物到动物的信号级联模式早期海胆胚胎。3)Wnt/β-catenin信号通路在许多生物体的模式形成中起着重要作用。最近的研究提供了强有力的证据表明，这一途径的组成部分参与了海胆胚胎动植物轴上细胞命运的分配。他将利用GSK3、C-钙粘蛋白和突变的(激活的)β-连环蛋白mRNAs的过度表达，结合胚胎操作和分子标记来阐明这一途径在模式形成中的作用。埃滕森博士将利用胚胎分离研究来测试一个核心问题，即在海胆(可能还有其他后生动物胚胎)中，β-连环素核定位的发育程序化模式是依赖于细胞-细胞信号，还是受到细胞自主机制的调控。最后，他将研究抑制Wnt/β-catenin途径阻止骨骼发育规范的机制。