48.4 Saturday, Jan. 5 The relationship between life history in temperate and tropical bird species and lipids in fibroblast mitochondrial membranes CALHOON, E.A.*; JIMENEZ, A.G.; HARPER, J.M.; JURKOWITZ , M.S.; WILLIAMS, J.B.; Ohio State University; Ohio State University; University of Michigan; Ohio State University; Ohio State University firstname.lastname@example.org
Temperate birds are thought to have a fast pace of life, having a shorter life-span with high reproductive output, whereas tropical birds are thought to have a slow pace of life. In support of this idea, tropical birds have lower metabolic rate, invest fewer resources in reproduction, and have higher adult survival rates compared with temperate birds. How these differences in life-history at the organismal level may be rooted in differences at the cellular level remains unknown. Here, we cultured fibroblasts of phylogenetically-paired tropical and temperate species, isolated mitochondria from each, and compared their mitochondrial membrane lipids. We found that temperate bird species tended to have more mitochondrial lipids than tropical species, especially cardiolipin, but that temperate species did not have significantly more mitochondrial protein and lipids in their cells. Since cardiolipin is highly localized to the inner mitochondrial membrane, this could indicate that temperate birds have more inner mitochondrial membrane, but not a higher amount of mitochondria. We also found that mitochondria from tropical species had higher amounts of plasmalogens, a lipid that could serve as an antioxidant. Overall, our findings are consistent with the idea that there are underlying cellular physiological traits which could account for the differences in whole animal physiology between animals with different life histories.