保幼激素初级应答基因Kr-h1拮抗蜕皮激素诱导变态发育的分子机理

Juvenile hormone (JH) and molting hormone (20E) are the most important hormones which regulate insect metamorphosis. JH antagonizes the molecular action of 20E and determines the nature of molting, while 20E triggers larval molting and metamorphosis. RNA-seq showed that Kr-h1, the JH primary response gene, inhibited expression of 20E primary-response genes. ChIP-seq showed that the DNA binding elements of Kr-h1 in different insect species are not well conserved. Moreover, the transcriptional regulation mechanism of Kr-h1 was dual, with both promoting and suppressing effects. In this project, (1) we will verify the transcriptional inhibition of Kr-h1 on 20E primary-response genes by using genetic interaction experiments. (2) Combining the bioinformatics analysis of ChIP-seq, we will identify the DNA binding element of Kr-h1 by Dual Luciferase Assay and EMSA. (3) We will screen and identify the transcriptional co-activator/suppressor of Kr-h1 by IP-MS, RNAi and over-expression. This study will not only help better understand the antagonism mechanism of JH primary-response gene Kr-h1 in 20E-induced insect metamorphosis and the difference of JH-20E molecular interaction among different species, but also provide new targets and theoretical basis for pest control.

蜕皮激素（20E）和保幼激素（JH）协同调控昆虫的变态发育：20E诱导蜕皮和变态发生；JH拮抗20E信号而维持幼虫性状，决定蜕皮的本质。申请人前期通过RNA-seq发现JH初级应答基因Kr-h1抑制20E初级应答基因的转录表达；ChIP-seq数据显示不同物种间Kr-h1的DNA结合元件并不保守；组织特异性遗传操作和细胞双荧光素酶结果显示Kr-h1的转录调控具有促进和抑制的两重性。拟在此基础上：（1）通过果蝇遗传互作实验确证Kr-h1转录抑制20E关键初级应答基因的表达；（2）结合ChIP-seq分析，通过双荧光素酶系统和EMSA鉴定Kr-h1的DNA结合元件；（3）通过IP-MS、RNAi和过表达等方法筛选和鉴定Kr-h1的共转录促进/抑制因子。该研究不仅帮助阐明JH拮抗20E诱导变态的分子机制和不同物种间Kr-h1介导的JH-20E分子互作差异，也为害虫防治提供新的靶标位点和理论依据。

蜕皮激素（20E）和保幼激素（JH）协同调控昆虫的变态发育：20E诱导蜕皮和变态发生；JH拮抗20E信号而维持幼虫性状，决定蜕皮的本质。本实验室前期通过RNA-seq发现JH初级应答基因Kr-h1抑制20E初级应答基因的转录表达；ChIP-seq数据显示不同物种间Kr-h1的DNA结合元件并不保守；组织特异性遗传操作和细胞双荧光素酶结果显示Kr-h1的转录调控具有促进和抑制的两重性。在此基础上：（1）我们通过果蝇遗传互作实验确证了Kr-h1转录抑制20E关键初级应答基因的表达，从而拮抗20E信号传导；（2）结合ChIP-seq分析，通过双荧光素酶系统鉴定出Kr-h1在20E初级应答基因启动子上的DNA调控区域；（3）通过IP-MS等方法筛选和鉴定Kr-h1的共转录抑制因子。该研究不仅帮助阐明JH拮抗20E诱导变态的分子机制和不同物种间Kr-h1介导的JH-20E分子互作差异，也为害虫防治提供新的靶标位点和理论依据。