MYDGF depletion leads to a neutrophil-dependent defect in wound healing. (A) Caudal fins of 3 dpf WT or mydgf^−/− zebrafish larvae with mCherry-labeled neutrophils were wounded by thermal injury and fixed at 3 and 24 hpb. Neutrophils were counted in the burn area. (A and B) Representative images (A) and quantification (B) of neutrophils in the burn are shown; three independent replicates with n = 24 +/+ and 24 −/− at 3 hpb and 21 +/+ and 16 −/− at 24 hpb; scale bar = 100 µm. (C–F) Caudal fins of 2 dpf (for morpholinos) or 3 dpf (for all other experiments) larvae were wounded by thermal injury and fixed at 24, 48, and 72 hpb. Wound healing was determined by quantifying the area of tail fin regrowth, measured from the caudal arteriovenous loop to the wound edge. (C and D) Representative brightfield images (C) and quantification (D) of tail fin regrowth area in WT and mydgf^−/− larvae are shown; two independent replicates with n = 45 +/+ and 51 −/− at 24 hpb, 46 +/+ and 48 −/− at 48 hpb, and 41 +/+ and 47 −/− at 72 hpb; scale bar = 100 µm. (E and F) Representative brightfield images (E) and quantification (F) of tail fin regrowth area in WT (WT Rac2) or neutrophil motility–impaired (Rac2D57N) larvae, with or without mydgf-targeting morpholino #1, at 24 hpb; three independent replicates with n = 50 WT/control mo, 32 WT/mydgf mo, 48 D57N/control mo, and 32 D57N/mydgf mo; scale bar = 100 µm. In B, D, and F, data are expressed as mean with 95% CI; each symbol represents one larva, and different colors represent independent replicates. *, P < 0.05; **, P < 0.01; ****, P < 0.0001. P values were calculated by ANOVA with Tukey’s multiple comparisons.