Molecular Mechanisms of Thermal Tolerance in Drosophila

Brandeis University, Waltham MA

Investigators

Abstract

Temperature has a major impact on animal physiology, and the ability to withstand daily and seasonal fluctuations in environmental temperature is critical for survival. This challenge is particularly acute for small insects, which include major agricultural pests and animal disease vectors, from aphids and flies to mosquitoes. The body temperatures of these animals closely follow the ambient temperature, and their sensitivity to temperature, especially cold, is a key factor in determining their geographic distributions. In this project, the researchers will probe the molecular and cellular pathways through which animals adjust their physiology to withstand cooling, using the fruit fly Drosophila as a model. The key systems this animal uses to sense that the environmental temperature is dropping will be identified. Next, the researchers will examine how the initial sensation of cooling is communicated to and processed by the brain. Finally, the investigators will examine how signals from the brain act to adjust the animal's physiology so that key organ systems are able to cope with environmental change. From an intellectual perspective, these studies will provide insight into how an animal's senses can modulate its physiology, and into how an animal can respond to environmental challenges. This work is designed with several broader impact objectives. These include training undergraduate, graduate and post-doctoral fellows in biological research, providing experiential learning opportunities to engage undergraduate students in scientific research, providing mentored teaching opportunities for graduate students and post-doctoral fellows, and providing publicly available resources for the research and educational communities. Temperature affects all biological processes, and the ability to sustain physiological function despite fluctuations in body temperature is important for animal survival. In this proposal, the investigators will examine how animals withstand temperature fluctuations, particularly cooling, using the fruit fly Drosophila melanogaster as a model. The proposal uses a combination of molecular genetics, physiology and behavior to examine three main research goals. First, the cellular and molecular sensors through which cooling is detected to initiate physiological changes that confer cool tolerance will be identified and studied. Second, the cellular and molecular mechanisms involved in eliciting these physiological changes will be identified and examined. Third, the extent of inter-species variation and environmental plasticity in cool tolerance among multiple Drosophila species will be explored, identifying promising natural variants and regulatory strategies for further study. Together, these studies will provide insights into the cellular and molecular mechanisms by which animals sense temperature and modulate their thermotolerance to cope with fluctuations in environmental temperature.