Genetic Dissection of Juvenile Hormone Signaling Pathways

在昆虫中，幼虫激素（JH）是调节发育、变态和繁殖的关键激素。然而，对JH作用的分子机制知之甚少。本项目将研究果蝇（Drosophila melanogaster）和红粉甲虫（Tribolium castaneum）的JH信号通路。为了分离潜在的JH信号成分，在PI实验室开发并进行了果蝇遗传筛选。这项工作确定了四个编码Wnt信号通路负调控因子的基因，Wnt信号通路在所有动物的发育中都很重要。本项目将利用RNAi技术确定这四个基因在Tribolium中的功能保守性。耐甲氧丁烯（MET）被认为是JH受体的候选者，但在果蝇MET无效突变体是完全可行和可育的。PI实验室的研究表明，MET与另一种蛋白质在功能上是冗余的，生殖细胞表达（GCE）和MET - GCE双突变体的镶嵌分析将用于确定JH信号在不同组织中的功能。总体而言，本研究项目将确定更多参与JH作用的参与者，阐明Wnt与JH信号通路的相互作用，并评估JH在不同组织中的功能。由于JH作用是一组杀虫剂的重要靶点，该项目可能对新杀虫剂设计、杀虫剂抗性管理和环境安全具有重要意义。该项目的研究结果也将被纳入本科和研究生课程。这些实验为来自不同背景的研究生、本科生和高中生提供了教育和培训的机会。他们将通过主动学习发育生物学课程和在首席研究员实验室的实践经验，接触到科学发现的过程。该项目的更广泛影响还包括国际合作和国际培训计划。

In insects, juvenile hormone (JH) is a key hormone that regulates development, metamorphosis, and reproduction. Nevertheless, little is known about the molecular mechanisms of JH action. This project will study the JH signaling pathways in the fruit fly, Drosophila melanogaster, and the red flour beetle, Tribolium castaneum. A Drosophila genetic screen was developed and conducted in the PI's laboratory in order to isolate potential JH signaling components. This work identified four genes that encode negative regulators of the Wnt signaling pathway, a pathway important in the development of all animals. This project will determine the functional conservation of these four genes in Tribolium using RNAi. Methoprene-tolerant (MET) is considered to be a candidate for the JH receptor, but in Drosophila Met null mutants are completely viable and fertile. Research in the PI's laboratory has demonstrated that MET is functionally redundant with another protein, germ cell-expressed (GCE) and mosaic analysis of Met-gce double mutants will be employed to determine the function of JH signaling in different tissues. Overall this research project will identify more players in JH action, clarify the interaction of Wnt and JH signaling pathways, and evaluate the function of JH in different tissues. Because JH action is an important target for a group of insecticides, this project could have important implications for new insecticide design, insecticide resistance management, and environmental safety. Results of this project will also be integrated into the undergraduate and graduate courses. The proposed experiments offer educational and training opportunities for graduate, undergraduate and high school students from diverse backgrounds. They will be exposed to the process of scientific discovery through active learning in developmental biology coursework and hands-on experience in the principal investigator's laboratory. The broader impacts of this project also include international collaboration and international training program.