title: Longevity Is Linked to Mitochondrial Mutation Rates in Rockfish: A Test Using Poisson Regression.
abstract: The mitochondrial theory of ageing proposes that the cumulative effect of biochemical damage in mitochondria causes mitochondrial mutations and plays a key role in ageing. Numerous studies have applied comparative approaches to test one of the predictions of the theory: That the rate of mitochondrial mutations is negatively correlated with longevity. Comparative studies face three challenges in detecting correlates of mutation rate: Covariation of mutation rates between species due to ancestry, covariation between life-history traits, and difficulty obtaining accurate estimates of mutation rate. We address these challenges using a novel Poisson regression method to examine the link between mutation rate and lifespan in rockfish (Sebastes). This method has better performance than traditional sister-species comparisons when sister species are too recently diverged to give reliable estimates of mutation rate. Rockfish are an ideal model system: They have long life spans with indeterminate growth and little evidence of senescence, which minimizes the confounding tradeoffs between lifespan and fecundity. We show that lifespan in rockfish is negatively correlated to rate of mitochondrial mutation, but not the rate of nuclear mutation. The life history of rockfish allows us to conclude that this relationship is unlikely to be driven by the tradeoffs between longevity and fecundity, or by the frequency of DNA replications in the germline. Instead, the relationship is compatible with the hypothesis that mutation rates are reduced by selection in long-lived taxa to reduce the chance of mitochondrial damage over its lifespan, consistent with the mitochondrial theory of ageing.
authors.affiliation: Division of Evolution Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT, Australia xia.hua@anu.edu.au.
authors.forename: Xia
authors.initials: X
authors.lastname: Hua
authors.affiliation: Division of Evolution Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT, Australia Department of Ecology and Evolutionary Biology, Yale University.
authors.forename: Peter
authors.initials: P
authors.lastname: Cowman
authors.affiliation: Division of Evolution Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT, Australia Department of Biology, Macquarie University, North Ryde, NSW, Australia.
authors.forename: Dan
authors.initials: D
authors.lastname: Warren
authors.affiliation: Division of Evolution Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT, Australia.
authors.forename: Lindell
authors.initials: L
authors.lastname: Bromham
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004272:DNA, Mitochondrial / Q000235:genetics*; D005399:Fishes / Q000235:genetics* / Q000502:physiology*; D016018:Least-Squares Analysis; D008136:Longevity / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics*; D059645:Mutation Rate; D019655:Quantitative Trait, Heritable; D012044:Regression Analysis; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial
keywords: molecular evolution; sister pairs; substitution rates