Genetic Dissection of Juvenile Hormone Signaling Pathways

在昆虫中，保幼激素(JH)是一种调节发育、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。本项目将研究果蝇和红粉甲虫体内的JH信号通路。为了分离潜在的JH信号成分，在PI的实验室中开发并进行了果蝇遗传筛选。这项工作确定了四个编码Wnt信号通路负调节因子的基因，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。耐甲基丁二烯(MET)被认为是JH受体的候选基因，但在果蝇中，Met零突变体是完全可行和可生育的。PI实验室的研究已经证明MET与另一种蛋白质在功能上是冗余的，将采用生殖细胞表达(GCE)和Met-GCE双突变体的镶嵌分析来确定JH信号在不同组织中的功能。总体而言，本研究项目将发现更多的JH作用分子，阐明Wnt和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标，该项目可能对新的杀虫剂设计、抗药性管理和环境安全具有重要意义。该项目的成果也将纳入本科生和研究生课程。拟议的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机会。他们将通过在发育生物学课程中的积极学习和在首席调查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.