Juvenile Hormone Regulation of the Ecdysone Cascade in Insect Metamorphosis

在昆虫中，蜕皮激素引起蜕皮和变态，保幼激素（JH）允许蜕皮但阻止蜕皮激素的变态作用。正在进行的免疫细胞化学研究如何JH调制蜕皮激素诱导的转录因子级联在烟草天蛾，天蛾，蛹翼在成虫发育的开始将完成。 RNA干扰技术，以消除特定的mRNA在这一途径将被用来确定的作用，这级联的关键转录因子的图案形成和角质层沉积。同样的转录因子级联反应将进行分析，在蛹承诺的翅膀成虫盘和眼睛原基在蜕皮的最后幼虫阶段，并在蛹发育的开始。 JH在维持这两种成虫前体幼虫状态中的作用将通过动物和组织培养的实验操作来评估。Moling是一种仅出现在Manduca最后幼虫阶段的表皮蛋白，属于Takeout蛋白家族，其中包括一些JH结合蛋白。 重组Moling将通过杆状病毒系统生产，然后用于检测其是否与JH结合，如果是，将对结合进行表征。 此外，其消失的模式在表皮相对于蛹承诺的时间和广泛的表达的外观将进行免疫细胞化学研究。 推测的同源物莫林在果蝇中的JH调节将分析其存在和可能的作用，在幼虫表皮发育和变态。USP作为果蝇中可能的JH受体的作用正在与Grace Jones博士合作研究。 JH在预防腹部变态中的生物测定将使用假设具有很少或没有JH结合活性的USP突变形式的动物进行。

In insects ecdysone causes molting and metamorphosis and juvenile hormone (JH) allows molting but prevents the metamorphic action of ecdysone. Ongoing immunocytochemical studies of how JH modulates the ecdysone-induced cascade of transcription factors in the tobacco hornworm, Manduca sexta, pupal wing at the outset of adult development will be completed. The technique of RNA interference to eliminate specific mRNAs in this pathway will be used to determine the roles of key transcription factors of this cascade in pattern formation and cuticle deposition. This same transcription factor cascade will be analyzed immunocytochemically during pupal commitment of the wing imaginal disc and of the eye primordium during the molt to the final larval stage and at the initiation of pupal development. The role of JH in the maintenance of the larval state of these two adult precursors will be assessed by experimental manipulations, both in the animal and in tissue cultureMoling, an epidermal protein that appears only in the last larval stage of Manduca, belongs to the Takeout family of proteins that includes some JH-binding proteins. Recombinant Moling will be produced by a baculovirus system, then used to test whether it binds JH and, if so, the binding will be characterized. Also, the pattern of its disappearance in the epidermis relative to the time of pupal commitment and the appearance of Broad expression will be studied immunocytochemically. Putative homologs of Moling in Drosophila that are regulated by JH will be analyzed for their presence and possible role in larval epidermal development and metamorphosis. The role of USP as a possible JH receptor in Drosophila is being studied in collaboration with Dr. Grace Jones. Bioassays of JH in the prevention of abdominal metamorphosis will be done with animals bearing mutated forms of USP hypothesized to have little or no JH binding activity.