Endocrine Control of Imaginal Disk Growth

昆虫的成虫盘是在幼虫生命期间在内部生长的组织，并且在变态期间将转变成成虫的眼睛、翅膀、腿、口器和生殖器。 控制成虫盘生长和发育的机制是发育生物学家广泛研究的主题。 一种新的生长因子已被发现，调节翅成虫盘的生长。 已经获得的证据表明，这种因子是神经激素蚕毒素，胰岛素样蛋白质家族的一员。 在离体培养的翅盘中，蜕皮激素与蜕皮激素共同作用，诱导翅盘的正常生长。 在正常生活中，这种生长因子在血液中的水平取决于食物摄入量，它似乎是内部组织生长与整体身体生长和营养协调的机制的一部分。 拟开展的工作将克隆和测序家蚕毒素基因，并研究家蚕毒素和蜕皮激素在调节细胞生长和细胞分裂中的相对作用。 此外，还将进行研究，以阐明营养变化引起血液中蚕毒素和蜕皮激素水平变化的机制，以及这些激素水平的变化如何反过来调节正常的生长和发育。 由于蚕毒素是胰岛素家族的一员，这项研究将有助于阐明这些重要激素在调节不同身体部位的相对生长中所起的作用，并将增强我们对胰岛素如何调节生长以应对营养变化的理解。 这项研究还将支持研究生和本科生的培训和教育。

The imaginal disks of insects are tissues that grow internally during larval life and that will transform into the eyes, wings, legs, mouthparts and genitalia of the adult insect during metamorphosis. The mechanisms that control the growth and development of imaginal disks are the subject of extensive investigation by developmental biologists. A new growth factor has been discovered that regulates the growth of wing imaginal disks. Evidence has been obtained that this factor is the neurohormone bombyxin, a member of the family of insulin-like proteins. Bombyxin acts together with the steroid hormone ecdysone, to induce normal growth in cultured wing imaginal disks. In normal life, the level of this growth factor in the blood depends on the amount of food intake, and it appears to be part of the mechanism by which the growth of internal tissues is coordinated with overall body growth and nutrition. The proposed work will clone and sequence the genes for bombyxin, and study the relative roles of bombyxin and ecdysone in the regulation of cell growth and cell division. In addition, studies will be done to elucidate the mechanisms by which variation in nutrition causes changes in the blood-level of bombyxin and ecdysone, and how variation in the level of these hormones in turn regulate normal growth and development. Because bombyxin is a member of the insulin family, this research will help shed light on the roles these important hormones play in regulating the relative growth of different body parts, and will enhance our understanding of how insulin regulates growth in response to variation in nutrition. This research will also support the training and education of graduate and undergraduates students.