Meeting Abstract
Repeated or chronic stress, such as that caused by anthropogenic activity and environmental disturbance, may affect animal health and fitness and contribute to population declines. However, the physiological impacts of repeated stress have not been extensively studied in wild animals, hindering development of stress biomarkers. Baseline endocrine measurements are commonly used for stress diagnosis, but they may be less robust indicators of stress than their downstream molecular mediators. We used proteomics to examine changes in protein expression in the blubber of northern elephant seals (Mirounga angustirostris) in response to multiple stress challenges. We simulated chronic stress by administering adrenocorticotropic hormone (ACTH) to juvenile seals once daily for four days and collected blubber before and after the first (“acute”) and last (“repeated”) administrations. We isolated and sequenced the proteome and identified 8793 proteins in elephant seal blubber. Across the proteome, 46 KEGG pathways were enriched, such as carbon metabolism, glycolysis/gluconeogenesis, fatty acid degradation, and fatty acid metabolism. For differentially expressed proteins, we compared protein abundance across stress states using isobaric labeled tags. Proteins that were differentially in response to ACTH were associated with lipid binding, pentose phosphate pathway, lipid transfer, and other cell maintenance pathways. The stress markers identified in this study may be used to assess stress states in vulnerable marine mammal populations using targeted assays.
