Macrophage Nrf2 is required for the timely detection of epithelial wounds in vivo. (A) Nrf2^RNAi macrophages exhibited reduced interest in sites of epithelial damage. (B) Definition of meandering index (persistence) and angle of migration (bias) towards epithelial wounds. (C–H) Quantification of meandering index (C and D), angle of migration (E), number of macrophages recruited to the site of damage 1-h post-wounding (F) and average speed (G and H) in control and srp > Nrf2^RNAi stage 15 macrophages. (I) Evaluation of Nrf2 mRNA levels by RT-qPCR within embryonic macrophages and in cells other than macrophages in control and srp > Nrf2-RNAi embryos; data from two independent biological replicates. (J) Evaluation of Nrf2 mRNA levels by RT-qPCR in control and UAS-Nrf2^RNAi embryos. (K) Evaluation of Prip mRNA levels by RT-qPCR in control and H99 mutant embryos. In A, sites of epithelial damage are marked by a white dashed outline, macrophages are labeled in green (srp > GFP), macrophage nuclei are labeled in red (srp-H2A::mcherry). Data (C, G, I, and J) generated using Nrf2^RNAi Flybase ID FBtp0069370 and data (A, D–F, and H) generated using Nrf2^RNAi TRiP HMS02021. PW: post-wounding. ns: not significant, *, P < 0.05; **P < 0.01, ****P < 0.0001 via Mann-Whitney test (C, E, and H) or unpaired t test (D, F, and I). Data have been collected from 7 controls and 7 srp > Nrf2^RNAi embryos (C and G); 10 control and 9 srp > Nrf2^RNAi embryos (D and H); 9 control and 7 srp > Nrf2^RNAi embryos (E); 8 control and 8 srp > Nrf2^RNAi embryos (F). Also see Fig. 4.