Description
The common bottlenose dolphin is one of the most widely distributed marine mammals in the world. They reside in coastal estuaries, open ocean and semi-enclosed lagoons. Laguna Madre (LM; Texas), is the only hypersaline lagoon in the United States (> average salinity of 36 ppt). In LM, resident bottlenose dolphins have enhanced skin wound healing compared to hyposaline environments but the molecular mechanisms underlying this finding remain unexplored. MicroRNAs are small non-coding RNAs that act as master regulators of gene expression. These molecules are often used as biomarkers in humans and have great potential to reveal how marine mammals adapt to challenging salinity conditions, which are increasing as a result of usual flooding events. This study aims to compare miRNA profiles in skin tissue samples from bottlenose dolphins in the Chesapeake Bay, a temperate estuary with seasonally fluctuating salinity and LM. We will identify differentially expressed miRNAs between the two study populations using DESeq2. This analysis will help evaluate whether or not dolphins that reside in hypersaline conditions have distinct miRNA expression profiles that could potentially be associated with osmotic regulation, immune function or wound-healing pathways. Being able to understand molecular-level responses to environmental salinity variation will give us insight into the capacity to adapt and the resilience of coastal bottlenose dolphin populations. Ultimately these findings may help contribute to the development of molecular biomarkers for marine mammals in these specific environments under changing climate conditions.