title: A demographic analysis of the fitness cost of extended longevity in Caenorhabditis elegans.
abstract: We monitored survival and reproduction of 1000 individuals of Caenorhabditis elegans wild type (N2) and 800 individuals of clk-1 and daf-2, and used biodemographic analysis to address fitness as the integrative consequence of the entire age-specific schedules of survival and reproduction. Relative to N2, the mutants clk-1 and daf-2 extended average life span by 27% and 111%, respectively, but reduced net reproductive rate by 44% and 18%. The net result of differences in survival and fertility was a significant differential in fitness, with both clk-1 (lambda = 2.74) and daf-2 (lambda = 3.78) at a disadvantage relative to N2 (lambda = 3.85). Demographic life table response experiment (LTRE) analysis revealed that the fitness differentials were due to negative effects in mutants on reproduction in the first 6-7 days of life. Fitness costs in clk-1 and daf-2 of C. elegans are consistent with the theory of antagonistic pleiotropy for the evolution of senescence.
authors.affiliation: Department of Nematology, University of California, Davis, CA 95616, USA.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Chen
authors.forename: Damla
authors.initials: D
authors.lastname: Senturk
authors.forename: Jane-Ling
authors.initials: JL
authors.lastname: Wang
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Müller
authors.forename: James R
authors.initials: JR
authors.lastname: Carey
authors.forename: Hal
authors.initials: H
authors.lastname: Caswell
authors.forename: Edward P
authors.initials: EP
authors.lastname: Caswell-Chen
mesh_terms: D000375:Aging; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D008136:Longevity; D008432:Mathematical Computing; D023421:Models, Animal; D009154:Mutation; D011972:Receptor, Insulin; D012098:Reproduction; D016019:Survival Analysis
chemical_list: C104339:CLK-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; C107483:DAF-2 protein, C elegans; D011972:Receptor, Insulin