Meeting Abstract
Flight in vertebrates places physical stress on many areas of the body, including the skin. The stratum corneum (SC) comprises the outermost 10-20 µm of the skin, and is composed of corneocytes embedded in a matrix of lipids, which contribute to the hydration and strength of the SC. Among mammals, bats have a unique SC lipid composition that includes cerebrosides, ceramides with a sugar moiety attached to the headgroup. Cerebrosides interact with water more strongly than other lipid molecules in the SC, and thus may play a large role in hydrating the SC. Furthermore, cerebrosides are prominent in avian SC, suggesting convergent evolution in SC lipid composition between birds and bats to provide the skin with the necessary moisture and strength for flight. We use thin layer chromatography to quantify lipid composition in four regions of the SC in the big brown bat (Eptesicus fuscus). In each region, we identified cholesterol esters, free fatty acids, cholesterol, ceramides, and cerebrosides, representing a more complex lipid composition than other mammals. Additionally, we correlate lipid composition with the stress each skin region experiences during flight. Our results indicate that the lipid composition of bat SC reflects their unique lifestyle.
