Fig. 1: mtd is upregulated allele-specifically by Traffic Jam (TJ) to extend lifespan under DR.

a Alternate (Alt) mtd allele prevents lifespan extension by dietary restriction across DGRP strains. Dots represent median strain lifespan on AL (red) or DR (blue). Black bars represent mean across all strains. n = minimum 100 flies per strain. Data are presented as mean values across a single strain. Error bars represent mean value across all strains per condition +/- SD. b Conditional whole body mtd^RNAi in adulthood reduces lifespan under DR conditions. Dashed lines = RNAi induced by RU486, solid lines = ethanol vehicle control. p value determined by log-rank test. c Homozygous mtd null allele dramatically reduces lifespan. Dashed lines = mtd^MI02920 null allele strain, solid lines = w¹¹¹⁸ control. p value determined by log-rank test. d mtd mRNA in w¹¹¹⁸ fly head is upregulated by DR. Values normalized to AL. Samples taken after 7 days on AL or DR. n = 5 whole flies or abdomens, 50 heads, or 10 thoraces per biological replicate across minimum 3 independent experiments. Error bars represent mean value across replicates +/- SD. e Constitutively active pan-neuronal mtd^RNAi in development and adulthood dramatically reduces lifespan compared to TRiP (empty vector) control. p value determined by log-rank test. f Conditional pan-neuronal mtd^RNAi induced by RU486 in adulthood reduces lifespan only under DR conditions. p value determined by log-rank test. g Overexpression of human OXR1, driven by mtd^T2A-Gal4 rescues loss of mtd. Dashed lines = homozygous mtd^MI02920 null allele flies, solid lines = heterozygous controls, and dashed with circles = homozygous mtd^MI02920 null allele with mtd-Gal4-driven hOXR1^OE. p value determined by log-rank test. h Conditional pan-neuronal overexpression of human OXR1 induced by RU486 in adulthood extends lifespan under DR conditions. p value determined by log-rank test. i Constitutively active overexpression of human OXR1 in development and adulthood extends lifespan. p value determined by log-rank test. j, DR increases mtd mRNA expression in heads of DGRP strains with the long-lived allele but not the short-lived allele. Samples taken after 7 days of AL or DR. n = 50 heads per replicate across 3 independent experiments. Error bars represent mean value across replicates +/- SD. k Schematic of LacZ reporter plasmid used for in vivo experiments in l–m. l LacZ staining is increased in whole brains from flies raised under DR transfected with cloned variant alleles from long-lived DGRP strains. Brains dissected after 7 days of AL or DR. n = 20 brains across 5 independent experiments. Error bars represent mean value across replicates +/- SD. m LacZ protein levels are increased in flies raised under DR transfected with long-lived variant allele reporter plasmid. Samples taken after 7 days of AL or DR. n = 20 heads per replicate across 5 independent experiments. Error bars represent mean value across replicates +/- SD. n Constitutively active pan-neuronal tj^RNAi reduces mtd expression in fly heads. Values normalized to AL. n = 20 heads per replicate across 3 independent experiments. Error bars represent mean value across replicates +/- SD. o Conditional pan-neuronal tj^RNAi induced in adulthood by RU486 reduces lifespan under DR. p value determined by log-rank test. For all figures, *p < 0.05, **p < 0.005, ***p < 0.0005. Except where noted, all p values were calculated by two-sided t-test. Figure 1k was generated using BioRender (publishing license: KW266MCH0G).