Stressful events can permanently modify how an organism functions. Those same conditions in adults can also be traced back to events early in life. Therefore understanding how organisms respond to environmental stress is crucial. However, this has been challenging partly because although responses to stress have been studied at but the cellular and whole organism level, scientists have not yet made a successful link between stress to the whole animal and the cellular consequences. The goals of the project are to 1) improve our understanding of stress responses at both levels and 2) critically evaluate how the stress response is regulated. This project also aims to improve science literacy and inquiry-based science education in rural regions of Alabama. First, this project will contribute to a more holistic view of how organisms respond to stress, and will teach middle and high-school students how events at molecular and whole-animal levels are interconnected. Second, models describing stress response regulation have been applied to evaluate diseases risk factors, e.g., obesity and socioeconomic status. This project will educate Alabamian public school students about the consequences of obesity, lifestyle, and diet and how to overcome stress. Finally, the participation in, and quality of, science fair projects in southeastern Alabama has been extremely low, although such projects provide a great opportunity to implement an inquiry-based approach to science education. In collaboration with biology teachers, the project will provide training, mentorship, and opportunities to conduct science fair projects to spark interests in biology, inspire scientific careers, and increase science literacy in regions historically underserved in STEM education.
Conceptualizing and studying stress has been challenging because stress responses extend across multiple biological scales, and the consequences of stress are often non-linear. This lack of integration is a major obstacle in this field, and is well exemplified by glucocorticoid- and heat shock protein-focused studies of stress responses. Therefore, this project will characterize an integrative stress response involving both HSPs and glucocorticoids. Specifically, this project will test the hypothesis that HSPs and glucocorticoids prime each other's response in preparation for subsequent stressors by determining whether 1) glucocorticoids elevate HSP and associated transcription factor and 2) a disruption in proteostasis, as regulated by the heat shock response pathway, elicits glucocorticoid responses. Elevation of HSPs and glucocorticoids has both protective and damaging effects. The allostasis model conceptualizes this non-linear nature of stress, yet this model has not been explicitly tested. Using zebra finches which adjust their heat tolerance with prior heat-conditioning, the project will also evaluate the allostasis model by testing the hypothesis that pre-conditioned birds elicit greater HSP and glucocorticoid responses than birds with no prior exposure to the stressor, thereby protecting individuals from stress-related suppression of reproductive and immune functions. By defining the direct and reciprocal relationship between HSP and glucocorticoid responses, this project will characterize organismal orchestration of the HSP response and provide a molecular basis for the switch from protective to damaging effects of glucocorticoids. Furthermore, this project will provide an in-depth evaluation of the allostasis model and whether this model applies to a stressor beyond nutritional stress.
