GENIC/MOLECULAR BASIS OF IMAGINAL DISC MORPHOGENESIS

成象盘形态发生的基因/分子基础

• 批准号: 3269802
• 负责人: JAMES W FRISTROM
• 金额: $ 28.59万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-01-01 至 1987-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3269802
• 关键词: cell differentiation; cytogenetics; ecdysone; electrofocusing; electron microscopy; enzyme linked immunosorbent assay; epithelium; fluorescence microscopy; gel electrophoresis; genetic manipulation; genetic mapping; genetic transcription; histogenesis; hormone regulation /control mechanism; immunodiffusion; juvenile hormones; membrane reconstitution /synthesis; messenger RNA; monoclonal antibody; nonmammalian vertebrate embryology; radioimmunoassay; regulatory gene; scanning electron microscopy

The imaginal discs of Drosophila are epithelial structures that are the embryonic precursors of adult cuticular structures, e.g. legs, wings, eyes. Mass-isolated imaginal discs undergo morphogenesis-evagination-to form appendages in vitro when incubated with the insect steroid hormone, 20-hydroxyecdysone. The hormone acts via the genome to elicit the developmental responses. Evagination itself results from short-distance movements of disc cells. We propose to identify the genes and their protein products in a major pathway leading to evagination. A master regulatory gene, located cytogenetically at 2B5, will be investigated through recovery of genomic clones and subsequent studies on the clones of binding of the receptor for 20-hydroxyecdysone to DNA acceptor sites, of transcriptional units expressed in larval and imaginal tissues, of changes caused by 2B5 mutants. Hormone-dependent transcripts from other loci will be identified using cDNA cloning. Because of the apparent involvement of membrane proteins in evagination, special efforts will be made to identify cDNA clones representing membrane proteins. Genes involved in evagination will be identified because of the absence of their transcripts in discs of 2B5 mutants that block evagination. Genes for membrane proteins and/or with hormone-dependent transcription will be localized cytogenetically by in situ hybridization. cDNA clones will be related to their protein products by comparing in vitro translation products to in vivo synthesized proteins. Membrane proteins will be mapped cytologically within discs using a combination of labelling and immunological techniques. Membrane glycoproteins whose glycosylation occurs via the dolichol-dependent pathway have been implicated in evagination and will be mapped cytologically and characterized structurally. These studies should provide insights into gene regulation during hormone-induced morphogenesis of an animal epithelium and provide an understanding of the functions of some hormone-dependent genes. The research also forms the basis for a long-term study on the genetics of membrane proteins. The basic knowledge gained will be relevant to the action of steroid hormones and to the normal and abnormal development of epithelia in humans.

果蝇的成虫盘是上皮结构， 成人角质层结构的胚胎前体，例如腿、翅膀、 眼睛。 质量隔离的成虫盘经历形态发生-外凸-形成 当与昆虫类固醇激素一起孵育时在体外形成附属物， 20-羟基蜕皮激素。 该激素通过基因组发挥作用，引发 发育反应。 逃逸本身是短距离造成的 椎间盘细胞的运动。 我们建议鉴定基因及其 蛋白质产物是导致外泄的主要途径。 大师 将研究细胞遗传学上位于 2B5 的调节基因 通过基因组克隆的恢复和对克隆的后续研究 20-羟基蜕皮激素受体与 DNA 受体位点的结合 幼虫和成虫组织中表达的转录单位的变化 由2B5突变体引起。 来自其他位点的激素依赖性转录本将 可以通过 cDNA 克隆进行鉴定。 由于明显的参与 外凸中的膜蛋白，将做出特别努力来识别 代表膜蛋白的 cDNA 克隆。 参与外逃的基因 将被识别，因为光盘中没有他们的转录本 阻止外翻的 2B5 突变体。 膜蛋白基因和/或 激素依赖性转录将通过细胞遗传学定位 原位杂交。 cDNA克隆将与其蛋白质相关 通过将体外翻译产物与体内合成产物进行比较 蛋白质。 膜蛋白将在椎间盘内进行细胞学定位 结合使用标记和免疫学技术。 膜 糖基化通过多醇依赖性途径发生的糖蛋白 与外翻有关，并将在细胞学上进行绘制 结构上有特点。 这些研究应该提供以下见解： 激素诱导的动物形态发生过程中的基因调控 上皮细胞并提供对某些功能的理解 激素依赖性基因。 该研究还为长期研究奠定了基础 膜蛋白遗传学研究。 所获得的基础知识 将与类固醇激素的作用以及正常和 人类上皮细胞发育异常。