Meeting Abstract
Individuals often display considerable variation in how each responds to stressors. The stress response has historically been evaluated by quantifying circulating levels of glucocorticoids. Yet, this approach has had limited value in understanding why two individuals would have different physiological responses to the same endocrine signal. One variable that could contribute to this variation is the unfolded protein response (UPR). The UPR is activated by accumulation of misfolded proteins, which often result from environmental stressors. The UPR affects the cells’ physiological function and secretory activity. In this study, we evaluate the relationship between the UPR, corticosterone levels, and mitochondrial physiology in deer mice (Peromyscus maniculatus). Mitochondrial physiology provides a strong indicator of the condition and energetic capacity of the individual and may be impacted by exogenous and endogenous stressors. Ear punches were collected and relative responsiveness of cultured fibroblasts to tunicamycin, a compound stimulating protein unfolding, was quantified by evaluating the expression of different chaperones. The mice were then released into seminatural enclosures where they will be maintained in a natural social structure for 6 months. After that period, mitochondrial respiratory capacity and reactive oxygen species production will be evaluated in liver and skeletal muscle. Mice with a higher UPR and lower corticosterone level are predicted to display higher mitochondrial performance than mice with a lower UPR.
