Meeting Abstract
17.5 Sunday, Jan. 4 Understanding regulation of adaptive changes in skeletal muscle physiology of Weddell seals: A proteomics approach CABLE, AE*; KANATOUS, SB; Colorado State University; Colorado State University amber.e.cable@gmail.com
Weddell seals (Leptonychotes weddelli) are elite diving mammals that use aerobic respiration in their swimming muscles during prolonged periods of hypoxia. Upon cessation of weaning and commencement of diving, Weddell seals generally experience developmental changes in muscle physiology that parallel changes in activity. In contrast to terrestrial mammals, where this developmental trend in increasing exercise capacity occurs from birth, Weddell seals pups have the highest percentage of type I slow oxidative fibers as well as the highest mitochondrial densities of any age class. The purpose of this study was to use proteomics to gain further understanding on mechanisms regulating adaptive changes in muscle physiology between three distinct age classes: pups (3-5 weeks old/non-divers), juveniles (1-2 years old/novice divers) and adults (7+ years old/expert divers). Juveniles showed the highest expression of myoglobin (9.9% volume compared to 8.8 and 7.2 in adults and pups, respectively). These initial results support previous findings that myoglobin concentrations differ with behavioral differences in diving activity, which is supported by aerobic metabolism in the skeletal muscles. With this success, we anticipate finding unique protein identifications in the three age classes that parallel age-related changes in diving activity. Knowledge of regulatory mechanisms of muscle development in this unique model is valuable due to potential pharmacological implications for treating human disease, specifically those that involve hypoxic conditions such as cardiovascular and pulmonary diseases. Furthermore, protein identification of the pups highly oxidative skeletal muscle can potentially provide insight on human obesity by linking energetics, brown adipose progenitors, and skeletal muscle.
