Positional identity in the zebrafish embryo

描述(申请人提供)：在脊椎动物发育期间，胚胎被细分为与细胞功能最终特化相关的领域。多个转录因子的区域表达和功能，相互拮抗和协同作用，定义了这些结构域的独特身份。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。发现遗传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潜在机制的重要一步。在这个项目中合作的研究人员有共同的科学兴趣和方法的历史，都使用斑马鱼，一种特别适合于遗传、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作用于控制特定区域的细胞分化？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，他们问：这些基因所需的作用是什么？他们的表达是如何控制的？而且，转录因子的组合是如何共同作用来调节执行特定位置功能的下游效应基因的呢？每个项目都将研究不同组织的图案：中胚层胚层；库普弗氏囊泡，左右图案的来源；以及背部视网膜。比较这些系统的结果将使我们能够寻找转录因子或效应器基因共同作用的一般原理，以及不同组织是否存在特定的分子相互作用。除了这种智力上的协同作用，这项应用还将提供共同的资源，以允许在大型实验上进行合作，而这些实验是每个小组单独无法完成的。斑马鱼遗传学核心设施将容纳现有的野生型和突变型鱼类，产生用于遗传筛选的动物，并为表型分析提供资源。分子分析核心设施将对突变基因组进行基于序列的筛选(TILLING)，对已识别的突变进行基因分型，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，该计划将识别调控脊椎动物组织模式基本步骤的分子通路的新组件，发现允许细胞表达特定位置命运和行为的效应基因，并开始剖析在发育过程中控制位置认同的遗传网络。

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.