The Chemical and Neural Control of Insect Metamorphosis

昆虫的生长和变态主要受蜕皮的控制 激素、20-羟基蜕皮激素（20 HE）和保幼激素（JH）， 当存在时，防止变态。 一种神经肽，羽化激素， 在每次蜕皮结束时引发蜕皮 在接下来的五年里， 该项目将重点关注这些激素在这种情况下的作用 烟草天蛾Manduca sexta中已鉴定的基因， 果蝇，果蝇。 具体项目包括：1） 蜕皮激素受体的时空分布 表皮在幼虫蜕皮和幼虫蛹转化和 它们与细胞应答能力的关系 激素. 2)昆虫花青素基因的结构分析 色素必要的适应性着色，激素调节其 表达，以及参与这种双向分泌的因子 蛋白 3)20 HE在细胞内的双重作用（诱导和抑制） 确定多巴脱羧酶基因表达的时间， 蜕皮后表皮黑化和变硬所必需的酶。 4)蜕皮激素在羽化激素基因调控中的作用 表达和这两种激素在酒精发作 果蝇成虫羽化时脱氢酶基因的表达。 这些研究将澄清我们对20HE和JH如何作用的理解 在幼虫蜕皮期间， 变态和如何改变蜕皮激素滴度可能协调 蜕皮期间基因表达的开始。 此外，他们将定义 这是第一次在一个复杂的系统中， 激素相互作用以控制特定基因表达。 这种深入 关于这些关键发展的作用模式的知识 激素也应该作为昆虫新方法的基础。 控制

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.