Meeting Abstract

P1.56  Saturday, Jan. 4 15:30  Connections between non-mitochondrial phospholipid fatty acid composition and life history in temperate and tropical birds CALHOON, E.A.*; WILLIAMS, J.B.; Ohio State University; Ohio State University calhoon.18@osu.edu

Temperate birds tend to have a fast pace of life, having short life-spans with high reproductive output and high metabolic rate, whereas tropical birds tend to have a slower pace of life, apparently investing fewer resources in reproduction and having higher adult survival rates with lower metabolic rates. How these differences in life history at the organismal level are rooted in differences at the cellular level is a focus of current research. Increasing the saturation level of fatty acids in the phospholipids of cell membranes has been implicated in decreasing metabolic rate and oxidative stress, but this connection has been challenged and its validity may depend on which organelle the saturated fatty acids are located. Several studies have looked at the fatty acid content of phospholipids in whole cells and in mitochondria, but few, if any, have examined the fatty acid composition of non-mitochondrial membranes. Here, we cultured fibroblasts from phylogenetically-paired tropical and temperate bird species, isolated the mitochondria from the other organelles, and then compared non-mitochondrial membrane lipids between tropical and temperate birds using high-performance liquid chromatography-mass spectrometry. There was not a significant difference in the saturation level of fatty acids in phospholipids of non-mitochondrial membranes, indicating that non-mitochondrial membranes may not be important in the connections among the fatty acid content of cellular phospholipids, metabolism, and oxidative stress.