Meeting Abstract
Repeated or chronic stress, such as that caused by anthropogenic activity and environmental disturbance, can 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 biomarkers that conservation practitioners can use to identify chronically stressed individuals. 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 a non-targeted, multi-omics approach to profile global changes in target gene and protein abundance in response to acute and repeated stress in a marine mammal study system, the northern elephant seal (Mirounga asgustirostris). 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 (“chronic”) stress challenges. We then sequenced the blubber transcriptomes and proteomes using Illumina RNA sequencing and liquid chromatography tandem mass spectrometry, respectively. We developed computational pipelines to compare transcript and protein expression between stress states and identify cellular consequences and unique molecular markers of repeated stress in a marine mammal. These included factors that affect energy balance and other cell maintenance pathways in response to repeated stress. The stress markers identified in this study may be used to assess stress states in vulnerable marine mammal populations using targeted assays.
