REC has little impact on mtDNA copy number, longevity, or female fertility at 25°C. (A) mtDNA copy numbers per egg or relative mtDNA copy numbers per adult head from flies of different ages measured by qPCR for REC-Halo, REC^ΔMTS-Halo, and REC^KO-Halo. Data represent mean ± SD, one-way ANOVA test with Dunnett’s multiple comparisons; ns, P > 0.05 (n = 3 biological replicates). (B) Lifespan of REC-Halo, REC^ΔMTS-Halo, and REC^KO-Halo. n > 200 animals across two independent experiments for each genotype. (C) The number of eggs laid by each female over the first 20 d (n = 14–17 biological replicates) and the egg-to-adult (hatching and eclosing) rate over the first 10 d for REC-Halo, REC^ΔMTS-Halo, and REC^KO-Halo flies (n = 9 biological replicates). Data represent mean ± SD, one-way ANOVA test with Dunnett’s multiple comparisons; ns, P > 0.05.