CAREER - Insulin Signaling in Lygus hesperus: New Model Needed

Board Of Regents, Nshe, Obo University Of Nevada, Reno, Reno NV

Investigators

Abstract

This CAREER project focuses on insulin signaling in Lygus hesperus, the western tarnished plant bug. The project builds on the investigator’s previous work on signaling pathways involving insulin and other neuropeptides in insects, and more generally contributes to a better understanding of insect physiology. The research will expand knowledge of how insects use hormones and neurotransmitters to determine how to store energy, when to devote resources to growth and reproduction, and how to balance these needs with inevitable aging and death. Because this bug is a pest of several crops, a better understanding of its physiology may lead to improved strategies for protection of the food supply. The educational plan for this project includes creation of an insect physiology course, a much-needed addition to University of Nevada Reno’s current course offering, particularly for the scattered disciplines housing students studying insect science at the university. Results from the insulin signaling research will feed directly into course content as students research methods to design experiments to answer physiological questions emerging from the project. In addition, outreach to farmers and the public will provide information about how the research results can be applied to improve farming practices, and to demonstrate basic principles of insect physiology. In addition to course development and outreach activities, the project provides laboratory research opportunities for undergraduates. Insulin signaling is widely conserved among metazoans and is a central nexus for several physiological processes, including metabolism, lifespan, development, reproduction, and immunity. Insects are a diverse, species-rich group, and explorations in non-model organisms suggest that much remains to be understood about the roles of insulin signaling outside of traditional models such as Drosophila melanogaster. Therefore, the overall goal of this project is to gain greater insight into the functions of insulin signaling in Heteroptera, the true bugs. With this goal, L. hesperus, a pest insect capable of feeding on more than 100 species of host plants as well as other insects, was selected as a representative heteropteran to study insulin signaling. Multiple molecular approaches will be utilized to elucidate details of insulin signaling dynamics and their impacts on organism-scale physiological processes. The objectives of this project are to: (1) explore the role of insulin-like-peptide (ILP) signaling in carbohydrate storage in the L. hesperus fat body, (2) determine the roles of ILP signaling in reproduction, and (3) elucidate the dynamics of ILPs in regulating diapause. Ultimately, nutritional inputs and storage in L. hesperus must be finely balanced with the need to reproduce against the need to conserve resources during periods of low temperature and food scarcity. This project explores these dynamics and will provide a foundation for the investigator's career goal of understanding fundamental functions of neuropeptides and peptide hormones in insects and other arthropods. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.