Molecular Mechanisms in Development

发育中的分子机制

• 批准号: 9894651
• 负责人: THOMAS B. KORNBERG
• 金额: $ 91.99万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9894651
• 关键词: Animals; Blastoderm; Cells; Chemicals; Cytokinesis; Development; Drosophila genus; EGF gene; Embryo; Embryonic Development; Erinaceidae; Fibroblast Growth Factor; Filopodia; Fingers; Gene Expression; Genes; Genetic; Genome; Goals; Imaging Device; Investigation; Mediating; Molecular; Movement; Neuroglia; Neurons; Neurotransmitters; Nuclear; Oocytes; Organ; Organelles; Paracrine Communication; Pattern; Play; Process; Property; Proteins; Research; Role; Signal Transduction; Signaling Protein; Site; Source; Structure; Synapses; Thinness; Time; Tissues; Vertebrates; Wing; Work; base; blastocyst; cohort; fascinate; gastrulation; imaginal disc; intercellular communication; morphogens; notch protein; novel; nuclear division; programs; response

Project Summary/Abstract The goal of this program is to understand how informational molecules that pattern tissues and embryos distribute in space and time during development. We study signaling in Drosophila, investigating the Decapentaplegic, Hedgehog, FGF, EGF, Wg, Notch-Delta and Bicoid morphogen signaling proteins. Our thesis is that the mechanisms that move these proteins from their sources and distribute them to their targets involve cellular machines and organelles whose actions precisely regulate protein movement. Our work has identified novel processes that mediate movement of morphogen signaling proteins in tissues and embryos, and this proposal describes the approaches we will take to further characterize these processes and the machines and organelles that drive them. This work has its origins in two separate investigations. The first began with an analysis of the roles and functions of the engrailed (en) segmentation gene. Like most vertebrates, the Drosophila embryo undergoes a mid-blastula transition (MBT) prior to gastrulation, but the early stages of Drosophila development have unusual features - 13 synchronous, rapid nuclear divisions without cytokinesis. Although the dogma has been that the zygotic genome does not contribute to pre-MBT development, we discovered that zygotic gene expression in nuclear cycle 2 embryos is essential for normal development. We discovered functionally important zygotic en expression in nuclear cycle 2 embryos and identified a small cohort of genes expressed by the pre-blastoderm embryo. We also discovered that the Bicoid concentration gradient that organizes the embryo A/P axis forms from protein that is made in stage 14 oocytes and functions prior to nuclear cycle 7. These findings are the basis for the proposed program that investigates patterning in the early embryo and that already reveals that our understanding of this early, critical stage of development must change radically. The second began with our discovery of cytonemes, specialized filopodia that are involved in cell-cell signaling. This discovery led us to propose that signaling proteins move between cells in a manner similar to the way neurotransmitters exchange between pre- and post-synaptic cells – by transferring between signaling cells at synapses. Our work has established that synapses are present in the Drosophila wing imaginal disc at sites of cytoneme contact, that they involve proteins that have previously been shown to function and to be required at neuronal synapses, and that they are essential for paracrine signaling between non-neuronal cells. We have also obtained strong experimental evidence that cytonemes ferry signaling proteins between producing and receiving cells and we have identified several unexpected properties of cytonemes that have significant implications for mechanisms of pathfinding and signal transduction. The work we pursue develops new tools for imaging cytonemes and builds upon our previous findings to determine the roles, composition and functions of these remarkable organelles and this fascinating mechanism of contact-based signaling.

项目摘要/摘要 这个项目的目标是了解形成组织和胚胎图案的信息分子是如何 在发展过程中在空间和时间上分布。我们研究了果蝇中的信号，调查了 Decapentaplegic，Hedgehog，Fgf，EGF，Wg，Notch-Delta和双类形态原信号蛋白。我们的 论文的主题是将这些蛋白质从源头转移到目标的机制 涉及细胞机器和细胞器，它们的行为精确地调节蛋白质的运动。我们的工作已经完成 发现了在组织和胚胎中调节形态信号蛋白移动的新过程， 这份提案描述了我们将采取的方法，以进一步描述这些过程和 驱动它们的机器和细胞器。 这项工作源于两个不同的调查。第一个开始是分析角色和 渐进式(EN)分段基因的功能。像大多数脊椎动物一样，果蝇胚胎经历了 囊胚中期过渡(MBT)在原肠形成之前，但果蝇发育的早期阶段 不寻常的特征-13个同步的，快速的核分裂，没有胞质分裂。尽管教条一直是 合子基因组对MBT前发育没有贡献，我们发现合子基因 在核周期2胚胎中的表达是正常发育所必需的。我们发现在功能上 重要合子EN在核周期2胚胎中的表达并鉴定了一小部分表达的基因 通过前胚层胚胎。我们还发现，组织的双曲线浓度梯度 胚胎A/P轴由14期卵母细胞形成的蛋白质组成，其功能在核周期7之前。 这些发现是拟议的项目的基础，该项目研究早期胚胎的模式，并 已经表明，我们对这一发展的早期、关键阶段的理解必须彻底改变。 第二个开始是我们发现了细胞线，一种参与细胞-细胞信号传递的特殊丝状丝状线虫。 这一发现使我们提出信号蛋白在细胞之间移动的方式类似于 突触前和突触后细胞之间的神经递质交换-通过在信号转导细胞之间传递 突触。我们的工作已经证实，突触存在于果蝇的翅膀想象盘中的 细胞素接触，它们涉及以前已经被证明具有功能的蛋白质，并且在 神经性突触，它们是非神经细胞之间旁分泌信号所必需的。我们有 还获得了强有力的实验证据，细胞线虫在产生和传递信号蛋白之间 我们已经确定了细胞素的几个意想不到的属性，这些属性具有显著的 对寻路和信号转导机制的影响。我们从事的工作开发了新的工具 用于对细胞素进行成像，并建立在我们先前发现的基础上，以确定其角色、组成和功能 这些非凡的细胞器和这种基于接触的信号的迷人机制。