title: Shifts in rotifer life history in response to stable isotope enrichment: testing theories of isotope effects on organismal growth.
abstract: In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effectsin vivo. Here, I demonstrate profound changes in life histories of the rotiferBrachionus plicatilisfed15N-enriched algae (0.4-5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies.
authors.affiliation: Department of Environmental Science and Analytical Chemistry , Stockholm University , Svante Arrhenius väg 8, 10691 Stockholm , Sweden.
authors.forename: Elena
authors.identifier: 0000-0002-4192-6956
authors.initials: E
authors.lastname: Gorokhova
keywords: 15N-labelling; growth and life histories; isotope resonance theory; kinetic isotope effect; longevity; stable isotopes