HR: 0830h
AN: B31D-0343    [PDF]
TI: Analysis of growth and tissue replacement rates by stable sulfur isotope turnover.
AU: * Arneson, L S
EM: larneso@american.edu
AF: American University, Department of Biology Hurst Hall 4400 Massachusetts Ave NW, Washington, DC 20016
AU: Macko, S A
EM: sam8f@virginia.edu
AF: University of Virginia, Department of Environmental Sciences, Charlottesville, VA 22903
AU: MacAvoy, S E
EM: macavoy@american.edu
AF: American University, Department of Biology Hurst Hall 4400 Massachusetts Ave NW, Washington, DC 20016
AB: Stable isotope analysis has become a powerful tool to study animal ecology. Analysis of stable isotope ratios of elements such as carbon, nitrogen, sulfur, hydrogen, oxygen and others have been used to trace migratory routes, reconstruct dietary sources and determine the physiological condition of individual animals. The isotopes most commonly used are carbon, due to differential carbon fractionation in C3 and C4 plants, and nitrogen, due to the approximately 3$%$ enrichment in $^{15}$N per trophic level. Although all cells express sulfur-containing compounds, such as cysteine, methionine, and coenzyme A, the turnover rate of sulfur in tissues has not been examined in most studies, owing to the difficulty in determining the $\delta$$^{34}$S signature. In this study, we have assessed the rate of sulfur isotopic turnover in mouse tissues following a diet change from terrestrial (7$%$) to marine (19$%$) source. Turnover models reflecting both growth rate and metabolic tissue replacement will be developed for blood, liver, fat and muscle tissues.
DE: 0400 Biogeosciences
DE: 1040 Isotopic composition/chemistry
SC: Biogeosciences [B]
MN: 2003 Fall Meeting