title: Lifespan extension by dietary restriction in female Drosophila melanogaster is not caused by a reduction in vitellogenesis or ovarian activity.
abstract: Dietary restriction (DR) extends lifespan in a wide range of organisms. DR also reduces daily and lifetime fecundity. The latter may be an evolutionary adaptation to survive periods of food shortage. Reproductive rate is often negatively correlated with lifespan, and a reduced cost of reproduction could be the mechanism by which DR extends lifespan. We tested this hypothesis in Drosophila melanogaster females, by directly suppressing different aspects of reproduction and measuring the effect on the response of lifespan and age-specific mortality to DR. DR resulted in lifespan extension in females kept with males, in females kept without males, in females with vitellogenesis blocked by the mutant ovoD1 and in females with no germline as a result of X-irradiation. Moreover, rapid (48 h) changes in age-specific mortality, previously seen in fertile females switched between full feeding and DR, were also seen in ovoD1 females. Furthermore, these rapid changes in age-specific mortality in cohorts of fertile wild type females were not accompanied by concurrent changes in egg-production. These results indicate either that reduced reproduction is not necessary for lifespan extension by DR in Drosophila females, or that the relevant aspects of reproduction act upstream of our interventions and were therefore not blocked in our experiments.
authors.affiliation: Department of Biology, University College London, Darwin Building, Gower Street, WC1E 6BT, UK.
authors.forename: William
authors.initials: W
authors.lastname: Mair
authors.forename: Carla M
authors.initials: CM
authors.lastname: Sgrò
authors.forename: Alice P
authors.initials: AP
authors.lastname: Johnson
authors.forename: Tracey
authors.initials: T
authors.lastname: Chapman
authors.forename: Linda
authors.initials: L
authors.lastname: Partridge
mesh_terms: D000818:Animals; D031204:Caloric Restriction; D004331:Drosophila melanogaster / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology; D007247:Infertility, Female / Q000503:physiopathology; D008136:Longevity / Q000502:physiology*; D010060:Ovulation / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D014818:Vitellogenesis / Q000502:physiology*