Positional identity in the zebrafish embryo

描述（由申请人提供）：在脊椎动物发育过程中，胚胎被细分为与细胞功能最终特化相关的域。多个转录因子的区域表达和功能，拮抗和协同作用，定义了这些域的独特身份。这些转录因子之间复杂的相互作用调节着每个组织特有的细胞和分子事件。发现基因网络的位置控制如何导致细胞形态和功能是理解人类出生缺陷和疾病背后机制的重要一步。在这个项目中合作的研究人员有着共同的科学兴趣和方法，他们都使用斑马鱼，一种特别适合遗传、分子和胚胎操作的脊椎动物模式生物。这三个相互关联的组成部分项目将解决一个共同的主题：特定的调控基因如何控制区域特异性细胞分化？这三个项目都共同关注转录因子的作用，特别是T-box蛋白家族的成员，并提出：这些基因的必要作用是什么？他们的表情是如何控制的？转录因子的组合如何共同作用来调节执行位置特异性功能的下游效应基因？每个项目将研究不同组织的模式：中胚层；库普弗氏囊泡，左右图案的来源；还有视网膜背侧。比较这些系统之间的结果将使我们能够寻找转录因子或效应基因共同作用的一般原理，以及询问特定的分子相互作用是否在不同的组织中是共同的。除了这种智力上的协同作用之外，这个应用程序还将提供公共资源，以允许在大规模实验中进行合作，而这对于每个小组来说是不可能的。斑马鱼遗传核心设施将容纳现有的野生型和突变型鱼，为遗传筛选产生动物，并为表型分析提供资源。分子分析核心设施将进行基于序列的突变基因组筛选（TILLING），鉴定突变体的基因分型，并通过半自动原位杂交进行基因表达分析。通过项目之间的相互作用和使用核心单元，该计划将确定调节脊椎动物组织模式基本步骤的分子途径的新组成部分，发现允许细胞表达位置特异性命运和行为的效应基因，并开始剖析发育过程中控制位置身份的遗传网络。

DESCRIPTION (provided by applicant): During vertebrate development, the embryo is subdivided into domains that correlate with eventual specializations in cellular function. The regional expression and function of multiple transcription factors, acting antagonistically and in concert, define unique identities for these domains. Complex interactions among these transcription factors regulate cellular and molecular events that are unique to each tissue. Discovering how positional control of genetic networks leads to cellular form and function is an important step towards understanding the mechanisms underlying human birth defects and disease. The investigators collaborating in this program project have a history of common scientific interests and approaches, all using the zebrafish, a vertebrate model organism particularly suited to genetic, molecular, and embryonic manipulations. The three interrelated component projects will address a common theme: how do particular regulatory genes act to control region-specific cell differentiation? All three projects share a common focus on the roles of transcription factors, especially members of the T-box protein family, asking: what are the required roles of these genes? How is their expression controlled? And, how do combinations of transcription factors act together to regulate downstream effector genes that execute position-specific functions? Each project will study the patterning of a different tissue: the mesoderm germ layer; Kupffer's vesicle, a source of left-right patterning; and the dorsal retina. Comparing results among these systems will allow us to search for general principles by which transcription factors or effector genes act together, as well as to ask whether specific molecular interactions are common to different tissues. In addition to this intellectual synergy, this application will provide common resources to allow cooperation on large-scale experiments that were impossible for each group alone. A Zebrafish Genetics Core Facility will house existing wild-type and mutant fish, generate animals for genetic screens, and provide resources for phenotype analyses. A Molecular Analysis Core Facility will perform sequence-based screening of mutagenized genomes (TILLING), genotyping of identified mutants, and gene expression analysis by semi-automated in situ hybridization. Through interactions between the projects and using the core units, this program will identify new components of the molecular pathways that regulate fundamental steps in vertebrate tissue patterning, discover effector genes that allow cells to express position-specific fates and behaviors, and start to dissect the genetic networks that control positional identity during development.