Expansion of neutrophils in irf8 MO^sp morphants. (A-B′) WISH shows mpx RNA expression in 21 hpf control embryos (n = 44/44) and irf8 MO^sp morphants (n = 47/48). (C-D′) WISH shows lyz RNA expression in 30 hpf control embryos (n = 39/39) and irf8 MO^sp morphants (n = 38/38). (A-D′) Blue arrows indicate the WISH signals. (E,H) SB staining indicates mature neutrophils in the CHT region of 36 hpf control embryo (n = 53/53) and irf8 MO^sp morphant (n = 49/49). (E,H) Blue arrows indicate the SB signals. (F-G,I) Video-enhanced DIC microscopy shows in vivo image of macrophages and neutrophils in 42 hpf control embryos (n = 11/11) and irf8 MO^sp morphant (n = 10/10). (A′-B′) Dorsal views of the anterior yolk of the boxed regions in panels A and B (blue). (C′-D′) Higher magnification (×20) views of the boxed regions (blue) in panels C and D. (F) Blue and black arrowheads indicate the lysosome inside the macrophage and the long filopodia of macrophage, respectively. (G,I) Red arrows represent granules in neutrophils.