The Chemical and Neural Control of Insect Metamorphosis

昆虫变态的化学和神经控制

• 批准号: 9005202
• 负责人: Lynn Riddiford
• 金额: $ 36.1万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-12-01 至 1996-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9005202&HistoricalAwards=false
• 关键词: Chemical; Neural; Control; Insect; Metamorphosis

Insect growth and metamorphosis is controlled primarily by the molting hormone, 20-hydroxyecdysone (20HE), and juvenile hormone (JH) which, when present, prevents metamorphosis. A neuropeptide, eclosion hormone, then triggers ecdysis at the end of each molt. During the next 5 years, this project will focus on the action of these hormones in the context of identified genes in the tobacco hornworm, Manduca sexta, and the fruitfly, Drosophila melanogaster. The particular projects include: 1) The spatial and temporal patterning of ecdysteroid receptors in the epidermis during a larval molt and the larval-pupal transformation and their relationship to the competence of the cells to respond to the hormone. 2) Structural analysis of the gene for insecticyanin, the pigment necessary for adaptive coloration, hormonal regulation of its expression, and factors involved in the bidirectional secretion of this protein. 3) The dual role (induction and repression) of 20HE in determining the timing of expression of gene for dopa decarboxylase, the enzyme necessary for cuticular melanization and hardening after ecdysis. 4) The role of ecdysteroid in the regulation of eclosion hormone gene expression and of these two hormones in the onset of alcohol dehydrogenase gene expression at adult eclosion in Drosophila. These studies will clarify our understanding about how 20HE and JH act together to regulate specific genes during a larval molt and at metamorphosis and how the changing ecdysteroid titer may coordinate the onset of gene expression during a molt. Furthermore, they will define for the first time in a complex system how a neuropeptide and a steroid hormone interact to control specific gene expression. This in-depth knowledge about the mode of action of these critical developmental hormones should also serve as a basis for new approaches to insect control.

昆虫的生长和变态主要由蜕皮激素、20-羟基蜕皮激素(20HE)和保幼激素(JH)控制，当存在时，它们可以防止变态。一种神经肽，羽化激素，然后在每一次蜕皮结束时触发蜕皮。在接下来的5年里，这个项目将重点研究这些激素在烟草角虫和果蝇中已识别的基因中的作用。具体的研究项目包括：1)幼虫蜕皮和幼虫-蛹转化过程中表皮蜕皮类固醇受体的时空模式及其与细胞对激素反应能力的关系。2)昆虫花青素基因的结构分析，适应染色所需的色素，其表达的激素调节，以及参与该蛋白双向分泌的因素。3)20HE在决定多巴脱羧酶基因表达时间上的双重作用(诱导和抑制)，多巴脱羧酶是皮肤黑化和蜕皮后硬化所必需的酶。4)蜕皮激素在果蝇羽化激素基因表达调控中的作用，以及这两种激素在果蝇成虫羽化时乙醇脱氢酶基因表达启动中的作用。这些研究将澄清我们对20HE和JH如何在幼虫蜕皮和变态期间共同调控特定基因的理解，以及蜕皮类固醇滴度的变化如何协调蜕皮期间基因表达的开始。此外，他们将首次在一个复杂的系统中定义神经肽和类固醇激素如何相互作用来控制特定的基因表达。这种对这些关键发育激素作用方式的深入了解也应该成为控制昆虫的新方法的基础。