Integrating engineering theory and biological measures to model stress resilience, damage, and fitness-related consequences

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How organisms respond to a stressful situation varies greatly among individuals and partly depends on prior experience with the stressor. This variation makes predictions of how an individual or population of individuals will endure stressful events extremely difficult. Historically, studies on stress focused on stress responses rather than the consequences of variation in responses. Using a comparative approach with individual birds that have had prior exposure to mild heat stress, and those that have not, this project will integrate biology and engineering approaches to develop a model to predict when stressful events negatively impact reproduction. Further, the investigators will examine how stress resistance and resilience can be transmitted to the next generation. This project will integrate biology and engineering in research and educational activities for students in Alabama. First, to highlight the connection between biology and engineering, the project will teach high school students about technologies inspired by nature in a summer program. Second, this project will organize a career fair, showcasing careers that integrate science and engineering degrees and giving opportunities for the participants to meet professionals from diverse backgrounds. Finally, this project will develop a hands-on workshop where students in biology and engineering learn how to turn data into mathematical models and active learning courses on functional genomics and epigenetics. By incorporating physiology, genomics, and engineering through research and education, the project will provide training, mentorship, and opportunities to nurture interdisciplinary mindset in early-stage scientists. Organisms across taxa can increase stress resilience when conditioned to a mild stressor during development. At the same time, severe levels of stress may decrease fitness. This context-dependency makes it difficult to predict how a shift in an environment alters the fitness outcome of an individual and success of a population. Several theoretical models have been put forth to characterize responses to a stressor, yet predictive models and reliable biomarkers of stress resistance and resilience are still lacking. To bridge this gap, the goal of this project is to utilize path analysis and Damage-Healing Mechanics from material engineering to develop mechanistic and predictive mathematical models, linking developmental and adult environments, epigenetic modifications, stress-induced molecular and cellular damage, and fitness indices. Specifically, this project will test the hypotheses that persistent damage, such as DNA damage and lipid peroxidation, lowers reproductive output and that stress conditioning increases stress resistance through epigenetic regulation of genes controlling damage protection, repair, and removal. Using a previously established protocol of heat conditioning in zebra finches (Taeniopygia guttata), the present project will assess 1) whether mild heat conditioning in juveniles turns on damage protective mechanisms such as heat shock proteins, antioxidants, and DNA repair, reduces accumulation of damage induced by heat stress in adulthood, and minimizes the negative effects of heat stress on reproductive output, and 2) whether heat conditioning in the F1 generation causes epigenetic modification of genes regulating damage protection, repair, and removal in the F2 generation.This project was co-funded by the Integrative Ecological Physiology and the Physiological Mechanisms and Biomechanics programs in Integrative Organismal Systems.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.