Animal life-history traits fall within limited ecological space, a continuum referred to as a “slow-fast” life-history axis. Differences in life-history traits are thought to result from trade-offs between investment in reproduction or self-maintenance as mediated by the biotic and abiotic environment. Dogs seem to be an anomaly to the typical correlations within this life-history trade-offs, with smaller dogs having higher metabolic rates and longer lives compared with larger dogs. Thus, dogs provide a unique system to examine physiological consequences of life-history trade-offs. For example, small dogs tend to have longer lifespans, fewer pups per litter, faster but shorter growth trajectories, higher metabolic rates and, in general, larger metabolically active organs compared with large dogs. The mechanistic and metabolic consequences, at the cellular level, of this seemingly contradictory relationship between body mass and lifespan in this species has not been previously addressed. I proposed to use skin from non-invasive, routine surgeries such as tail-docks and/or dew-claw removal by veterinarians to isolate primary fibroblasts in puppies of different body masses. Additionally, I also propose to ask veterinarians to collect ear clips or declaws from dogs euthanized due to old age. The comparison of, not just different body sizes, but also age differences at the cellular level will be pivotal for this research question. Primary dermal fibroblasts will be used to explore physiological changes at the cellular level including 1) effects of reactive oxygen species (ROS) production and cellular damage and antioxidant capacity in dogs of different sizes and ages, and 2) cellular metabolic rates including basal oxygen consumption, proton leak, maximal oxygen consumption, and non-mitochondrial respiration, along with capacity for glycolysis and capacity for β-oxidation using a SeaHorse XF oxygen flux analyzer on isolated dermal fibroblasts cells. This research question can potentially provide answers regarding vital cellular factors that dictate aging in mammals.
affluent in tissue culture techniques
Number of Student Researchers
Applications open on 01/15/2017 and close on 02/07/2017