DORSAL/VENTRAL PATTERN FORMATION IN THE ZEBRAFISH EMBRYO

描述(改编自研究员摘要)：的长期目标 这项拟议的研究是为了确定参与 背腹轴的建立及精确分子测定 它们用来指定不同细胞类型的机制 沿着脊椎动物胚胎的背腹轴产生的。一个 广泛筛选影响斑马鱼形态发生的突变 结果发现了6个在植物生长发育过程中起关键作用的基因 建立背轴/腹轴。这些都是第一批 在脊椎动物模型系统中影响背腹模式的突变， 它们为研究这一现象的机制提供了一个独特的机会 重要的发展过程。之间的细胞移植实验 野生型和突变型胚胎将决定：(1)6个基因中的哪一个 起信号分子或产生信号的作用；(2) 基因的细胞功能是否建立在一个 细胞的特性；以及(3)每个基因的功能结构域 胚胎。非洲爪哇腹壁蛋白基因在斑马鱼中的异位表达 背靠背突变胚胎将决定(4)基因的顺序 在背腹轴的建立中起作用，并提供一个 该途径的分子框架。三种不同的方法将是 用来鉴定休眠基因的分子性质：A 候选基因方法、表达克隆方法和建立 位置克隆方法的基础。克隆的基因 在手中，将执行许多直接功能测试，具体取决于 特定背侧化基因预期的生化特性和 在这里提出的研究中建立的功能特性。 人类这些基因的突变很可能导致流产和 还有先天缺陷。对这些机制的理解 背腹基因在正常发育中的功能可能有直接的 在理解癌症和分子进展中的意义 人类遗传性疾病的机制。

DESCRIPTION (adapted from investigator's abstract): The long-term goals of the proposed research are to identify the genes involved in the establishment of the dorsal-ventral axis and determine the precise molecular mechanisms by which they function to specify the different cell types generated along the dorsal-ventral axis of the vertebrate embryo. An extensive screen for mutations affecting morphogenesis in the zebrafish resulted in the identification of 6 genes with key functions in the establishment of the dorsal/ventral axis. These are among the first mutations affecting dorsal-ventral patterning in a vertebrate model system, and they provide a unique opportunity to study the mechanism of this important developmental process. Cell transplantation experiments between wild-type and mutant embryos will determine: (1) which of the 6 genes function as a signaling molecule or in the generation of a signal; (2) whether the cellular function of the gene is in the establishment within a cell of its identity; and (3) the functional domains of each gene within the embryo. Ectopic expression of Xenopus ventralizing genes in the zebrafish dorsalized mutant embryos will determine (4) the order in which the genes function in the establishment of the dorsal-ventral axis and provide a molecular framework for the pathway. Three different approaches will be utilized to identify the molecular nature of the dorsalized genes: a candidate gene approach, expression cloning methodologies, and establishment of the foundation for a positional cloning approach. With the cloned genes in hand, numerous direct tests of function will be performed depending on the biochemical properties expected of the particular dorsalized gene and the functional properties established in the studies proposed here. Mutations in these genes in humans are likely to result in miscarriage and also birth defects. The understanding of the mechanisms by which these dorsal-ventral genes function in normal development is likely to have direct implications in the understanding of the progression of cancer and molecular mechanisms of human inherited disorders.