EGG TO EMBRYO--GENE REGULATORY CIRCUITRY IN DEVELOPMENT

组成该计划项目的三个实验室的研究重点是早期胚胎发育调控流的分子基础。该计划项目将利用高度发达的海胆和海鞘模型系统进行这项研究。主要目标是利用在基因调控网络的不同水平上操作的基因，对控制早期胚胎空间表达的基因的顺式调控系统进行功能理解；了解这个网络的总体结构；并了解母体转录因子被激活的分子机制，以及控制从母体调控过程转变为合子调控过程的分子机制。这三个研究组成部分是：(1)Davidson组成部分，“基因调控机制和早期胚胎发育的控制”；(2)Fraser组成部分，“早期胚胎中基因调控事件的活体成像”；(3)Levine组成部分，“海鞘肠囊中的基因调控”。Davidson组分的主要目的是对海胆胚胎中差异表达的基因进行顺式调控分析，并鉴定和鉴定控制这种表达的母体和合子转录因子。Fraser组件的主要关注点是利用Davidson组件特有的实验系统，通过母体转录因子修饰的新成像方法来可视化体内顺式调控元件的状态和空间可视化。Levine组分的主要重点将是对海鞘胚胎中表达的某些关键调控基因进行顺式调控分析，这些基因也将在Davidson组分的海胆胚胎中表现出来，以及Davidson和Levine实验室将合作进行的系间基因转移实验。这项拟议研究的一个显著特点是采用了强大的新技术，其中一些是全新的。所有的组件。将依赖两个研究核心设施，即加州理工学院海洋实验室的SUM设施，该设施将提供海胆、配子和核提取物，从中提纯转录因子；以及微测序设施，部分纯化的转录因子在皮摩尔水平上进行测序。行政核心将监督管理、预算和实验室间的沟通，涉及材料、财务和智力问题。

The focus of research in the three laboratories that constitute this Program Project is the molecular basis of regulatory flow in early embryonic development. The Program Project will utilize the highly developed sea urchin and ascidian model systems for this research. Major objective are to develop functional comprehension of cis-regulatory systems that control genes expressed spatially in the early embryo, using genes that operate at different levels of the gene regulatory network; to discern the overall architecture of this network; and to discern the molecular mechanisms by which maternal transcription factors are activated, and control is transformed from maternal to zygotic regulatory processes. The three Research Components are:(1) Davidson Component, "Gene Regulatory Mechanisms and the Control of Early Embryogenesis"; (2) Fraser Component, "In Vivo Imaging of Gene Regulatory Events in the Early Embryo"; (3) Levine Component "Gene Regulation in the Ascidian Ciona intestinalis." The major aims of the Davidson Component are cis-regulatory analysis of genes expressed differentially in the sea urchin embryo, and identification and characterization of the maternal and zygotic transcription factors which control this expression. The major focus of the Fraser Component is visualization of the state of cis-regulatory elements in vivo and spatial visualization by new imaging methods of modifications of maternal transcription factors, using experimental systems characterized in the Davidson Component. The major focus of the Levine Component will be cis-regulatory analysis of certain key regulatory genes expressed in ascidian embryos, which are also to be characterized in the sea urchin embryo in the Davidson Component, and interphyletic gene transfer experiments to be carried out collaboratively between the Davidson and Levine labs. A salient characteristic of the proposed research is the engagement of powerful new technologies, some entirely novel. All the Components. Will rely on two Research Core Facilities, viz the SUMS Facility at Caltech's Marine Laboratory, which will provide sea urchins, gametes and nuclear extracts from which transcription factors are purified; and the Microsequencing Facility, where partially purified transcription factors are sequenced at picomole levels. An Administrative Core will oversee management, budget, and interlaboratory communication, with respect to material, financial, and intellectual matters.