Meeting Abstract

P3.65  Wednesday, Jan. 6  Unmasking age class-specific differences in the Weddell seal proteome CABLE, A.E.*; DE MIRANDA, M.A.; KANATOUS, S.B.; Colorado State University ; Colorado State University; Colorado State University amber.e.cable@gmail.com

During prolonged periods of hypoxia, Weddell seals (Leptonychotes weddelli) and other diving mammals are adapted to rely on internal oxygen stores to fuel aerobic energy production in their primary swimming muscles. Interestingly, nondiving Weddell seal pups are born with a higher potential for aerobic output than elite diving adults, as seen in the higher percentage of type I slow oxidative fibers in pups. Because this developmental trend is opposite that of terrestrial mammals, the process through which this adaptive change occurs is not well understood. The goal of this study is to better understand the differences in skeletal muscle physiology of this unique model system using proteomics to generate protein signatures from the two physiologically distinct age classes: pups (age 3-5 weeks; nondivers) and adults (age 7+ years; expert divers). Building on previous proteomic data confirming the reliance on cross-species analysis, this study found a suite of protein identifications for both age classes that are consistent with skeletal muscle physiology. Several spots, however, consistently yielded unsuccessful protein matches, suggesting the presence of unique seal proteins. Furthermore, myoglobin was found in multiple gel spots, alluding to the possibility of myoglobin isoforms, which were previously thought to exist only in species of fish. Knowledge of these unique adaptations in skeletal muscle are valuable due to the potential pharmacological implications for treating human disease, specifically those that involve hypoxic conditions such as cardiovascular and pulmonary diseases. This research was supported by the NSF (grant #OPP-0440713).