Studies on multiple hormonal regulation of insectdevelopment by endocrine perturbation

在昆虫中，一种类固醇激素，20-羟基蜕皮酮(20E)，通过蜕皮激素受体(ECR)启动信号级联反应，在调节发育过渡过程中发挥重要作用。虽然20E被认为是蜕皮激素，但其前体蜕皮激素(E)对经典的ECR介导的反应几乎没有影响，因此被认为是一种相对活性较低的化合物。我阐明，不仅是20E，而且E对于调节果蝇的发育时序也是必不可少的。我还探索了一种系统，在该系统中，蜕皮类固醇水平通过异位表达失活酶来降低。通过使用该系统，我发现二龄幼虫的发育命运在较低的蜕皮激素水平下被转化为化蛹，而不是蜕皮到三龄。此外，我将3-氧代类固醇表征为蜕皮类固醇生物合成途径的组成部分。

In insects, a steroid hormone, 20-hydroxyecdysone (20E), plays important roles in the regulation of developmental transitions by initiating signaling cascades via the ecdysone receptor (EcR). Although 20E has been well characterized as the molting hormone, its precursor ecdysone (E) has been considered to be a relatively inactive compound because it has little or no effect on classic EcR mediated responses. I elucidate that not only 20E but also E is essential for the regulation of developmental timing in Drosophila melanogaster. I also explored a system in which ecdysteroid level is reduced by ectopic expression of an inactivating enzyme. By using the system, I find that developmental fate of second instar larva is converted to pupariation instead of molting to third instar at a low level of ecdysteroid. Further, I characterized 3-oxo steroids as components of the ecdysteroid biosynthetic pathway.