Macrophages remove repair patch.
(a-c) Repair patch (AnxA2a-mO, a, white arrow) and macrophages (mpeg1:GFP, b, white arrows) before (Initial), 240 s and 1,500 s after wounding. A macrophage ingests parts of repair patch (green arrows). (c) Merged views of a,b. Note the bleed-through of AnxA2a-mO into the GFP channel (b). (d) Repair patch removal in control (left, n=37) and macrophage-depleted embryos (KD, right, n=25, Fisher’s exact test P<10-8) over 20 h. (e) Crispr/Cas9 knock-out of irf8 impairs repair patch removal. In controls, the repair patch was removed in 32% of injured myofibers (n=19) within one hour after injury. In the irf8-KO embryos the patch was present in all cases of injured myofibers examined (n=15). This suggests that morpholino triple knock-down is inefficient and the same effect on macrophages can be achieved by elimination of irf8 at the stage analysed. Significance was checked with Fishers exact test at P<0.05 (P=0.023895). Scale bar, 4 µm.