Hormonal Control of Pupal Commitment of Metamorphosis

9728727 Nijhout变态是昆虫发育的关键时期之一，在此期间，未成熟的幼虫转变为成熟的成虫。 了解控制变态的机制对昆虫生理学和发育的许多领域至关重要。 Nijhout博士目前对变态的激素控制的理解主要依赖于来自表皮和一般体壁研究的信息。近几年来，研究所发现成虫的成虫盘（发育成成虫的腿、翅膀、触角和口器的结构）的变态似乎是以一种与一般表皮完全不同的方式控制的。 特别是，这些结构开始变态的发育过程比一般表皮早得多。 当保幼激素（控制昆虫发育进程的激素）在血液中处于高水平并且仍然有效地抑制表皮的变态时，想象盘开始变态。 PI已经开发了一系列的调查，以测试一系列的替代假设，可以解释这种分歧的表皮和成虫盘的发育的生理控制。 其中，PI将研究保幼激素和蜕皮激素的相对作用（蜕皮激素）控制与变态发育早期相关的基因表达模式、成虫盘和表皮对这些发育激素的相对敏感性，以及细胞的作用细胞通讯信号在确定时间和空间模式的发展承诺变态在这些组织。 通过比较了解表皮和成虫盘发育的控制，这些研究将为昆虫变态的控制机制提供更深入的了解。

9728727 Nijhout Metamorphosis is one of the critical periods in insects development, during which an immature larva transforms into a mature adult insect. Understanding the mechanisms that control metamorphosis is of critical importance to many areas of insect physiology and development. Dr. Nijhout's current understanding of the hormonal control of metamorphosis rests largely on information derived from studies on the epidermis and general body wall. The PI has found in recent years that metamorphosis of the imaginal disks, the structures that give rise to the legs, wings, antennae, and mouthparts of the adult insect, appear to be controlled in a manner quite different from that of the general epidermis. In particular, these structures begin the developmental process of metamorphosis much earlier than the general epidermis. Imaginal disks begin metamorphosis at a time when the level of juvenile hormone (the hormone that controls the progress of development of insects) is present at high levels in the blood and is still actively inhibiting metamorphosis of the epidermis. The PI has developed a series of investigations to test an array of alternative hypotheses that could explain this divergence of physiological control of development of epidermis and imaginal disks. Among others, the PI will study the relative roles of juvenile hormone and ecdysone (the molting hormone) in controlling the expression patterns of genes associated with the early stages of metamorphic development, the relative sensitivities of imaginal disks and epidermis to these developmental hormones, and the role of cell-cell communication signals in determining the timing and spatial pattern of the developmental commitment to metamorphosis in these tissues. By providing a comparative understanding of the control of development of epidermis and imaginal disks, these studies will provide a deeper insight into the mechanisms that control of insect metamorphosis.