DOI: 10.5061/dryad.cp38vj4
title: Data from: Evolution of longevity improves immunity in Drosophila

description: Much has been learned about the genetics of aging from studies in model
 organisms, but still little is known about naturally occurring alleles
 that contribute to variation in longevity. For example, analysis of
 mutants and transgenes has identified insulin signaling as a major
 regulator of longevity, yet whether standing variation in this pathway
 underlies microevolutionary changes in lifespan and correlated fitness
 traits remains largely unclear. Here we have analyzed the genomes of a set
 of Drosophila melanogaster lines that have been maintained under direct
 selection for postponed reproduction and indirect selection for longevity,
 relative to unselected control lines, for over 35 years. We identified
 many candidate loci shaped by selection for longevity and late-life
 fertility, but – contrary to expectation – we did not find
 overrepresentation of canonical longevity genes. Instead, we found an
 enrichment of immunity genes, particularly in the Toll pathway, suggesting
 that evolutionary changes in immune function might underpin – in part –
 the evolution of late-life fertility and longevity. To test whether this
 genomic signature is causative, we performed functional experiments. In
 contrast to control flies, long-lived flies tended to downregulate the
 expression of antimicrobial peptides upon infection with age yet survived
 fungal, bacterial and viral infections significantly better, consistent
 with alleviated immunosenescence. To examine whether genes of the Toll
 pathway directly affect longevity, we employed conditional knockdown using
 in vivo RNAi. In adults, RNAi against the Toll receptor extended lifespan,
 whereas silencing the pathway antagonist cactus – causing immune
 hyperactivation – dramatically shortened lifespan. Together, our results
 suggest that genetic changes in the age-dependent regulation of immune
 homeostasis might contribute to the evolution of longer life.
description: Raw data Fabian &
 Garschall et al. 2018Data associated with
 Fabian and Garschall et al. (2018), "Evolution of Longevity Improves
 Immunity in Drosophila", published in Evolution Letters. This file
 contains raw data for infection assays of long-lived selected and
 unselected control populations of Drosophila melanogaster and data on
 lifespan upon RNAi knockdown of immunity genes. For details see Fabian
 & Garschall et al. (2018). Sheet Infection Gene Expression: qRT-PCR
 average Ct values of 3 technical replicates, 24h after infection with E.
 carotovora carotovora 15, prick control and unchallenged pools of 5 female
 flies (per biological replicate). Sheet Infection Survival: Age at death
 (days) of females upon pathogen infection with B. bassiana, E. faecalis,
 E. carotovora carotovora 15 and Drosophila C Virus (DCV), with survival
 data right-censored after 14, 7, 7, and 7 days post infection,
 respectively. Sheet Bacterial Clearance: Total absence of bacterial growth
 (= total. 100% clearance) in both of two replicate spots of homogenate of
 a single female fly after infection with E. carotovora carotovora 15.
 Sheet Lifespan RNAi: Age at death (days) of da-GS-GAl4&gt;UAS-RNAi flies,
 targeting different immunity genes in the Toll pathway (RU486 =
 mifepristone = RNAi; EtOH = non-RNAi control). Data from F1 offspring of
 the control cross without RNAi knockdown are denoted as "w1118 x
 da-GS-Gal4".