Evaluating potential mechanisms underlying hormetic responses. Elizabeth J Ales, Erik C. Johnson. Biology, Wake Forest University, Winston-Salem, NC.

   Hormesis is the adaptive response that raises the resistance of an organism to physiological stress following low-level exposure to repeated periods of stress. Although hormesis has been shown to be present in diverse organisms and for many different types of stress, precise cellular mechanisms are unclear. We are employing the genetics of Drosophila to discern potential cellular mechanisms. We observe that exposure to multiple periods of short starvation conditions (12 hours) for a period of 3-4 days significantly extends lifespan upon transitioning to complete starvation conditions. Specifically, we find an increase of approximately 20% in median survival from multiple wild-type strains under this experimental paradigm. We are extending these experiments to include genetic screens of candidate molecules, such as insulin, AKH, and AMPK to test whether these molecules are involved in the adaptive responses underlying hormesis. Furthermore, we will report on our efforts to identify genetic changes in animals displaying hermetic responses. Lastly, we will report on efforts to identify potential differences or similarities in potential hermetic mechanisms from homotypic stress compared to heterotypic stressors. We suspect that our results will offer insight into the mechanisms underlying adaptive responses to physiological stressors.