Thermosensory Control of Multimodal Behavioral Adaptation and Optimization

Temperature is a significant factor that impacts all living organisms’ behavior and physiology. With climate change driving significant shifts in environmental temperatures, it is crucial to understand the mechanism by which animals adjust their behaviors to cope with these changes. Animals rely on thermosensation to sense environmental temperatures and adjust their behavior accordingly, and almost all behavioral traits have optimal temperatures at which the performance reaches maximal. However, it is largely unknown how thermosensation contributes to the behavior-specific thermal preferences. To address this, we aim to use the model organism Caenorhabditis elegans to uncover how thermosensory systems interact with other physiological processes to regulate complex behaviors. We have developed an automated multimodal assaying platform of C. elegans behavior. We will use this system for high-throughput assays of multiple behaviors (locomotion, egg-laying, and chemotaxis) under various temperatures to identify patterns in how these behaviors are adapted to temperature changes. Next, we will use the behavior-based assays to interrogate the previously identified neuronal substrate for the thermosensation and integration systems to map the circuits for thermosensory regulation of thermal optima of behaviors. Besides, we will employ the powerful genetics and neurophysiological toolset of the C. elegans model to characterize the neural functions of these neurons in this process. Through pilot experiments, we have already discovered that the TAX-4, a subunit of cyclic nucleotide-gated channel, strongly affects the thermal optimum of egg-laying behavior. Using this finding as an entry point, we will focus on investigating genes linked to the TAX-4 activity to identify the molecules responsible for the variation in thermal optima. Successful completion of the aims of this project will help to obtain a molecular and cellular understanding of the mechanisms that allow animals to execute adaptive behavioral responses to thermal variations and ultimately the changing climates.