(A-C) Tg(mpx:GFP) embryos were injected at the one cell stage with either p47phox morpholino (MO p47phox) or a control morpholino (MO CTRL). Steady-state neutrophil populations were imaged in 2 dpf morphants using fluorescence microscopy. Scale bar: 400 μm. (B) Neutrophil counts in whole larvae (mean number of neutrophils per larva ± SEM, NMO CTRL = 47 and NMO P47 = 47, Mann-Whitney test, two-tailed, **p<0.005, from three independent experiments). (C) At 2 dpf, p47phox and CTRL morphants were infected with E. coli-GFP in the notochord and imaged using fluorescence microscopy at 4 hpi and 1 dpi. Graph represents mean number of recruited neutrophils per larva ± SEM in the notochord region (NMO CTRL = 10–14 and NMO P47 = 12–16, Mann-Whitney test, one-tailed, p>0.05 ns: non significant, from two independent experiments). (D) p47phox and CTRL morphants were infected with E. coli-GFP in the notochord at 2 dpf and GFP fluorescence (bacteria) was imaged repeatedly in individual larva, fluorescence was overlaid with transmitted light images at 1 hpi and 1 dpi. Black arrowheads indicate the infection site, scale bar: 400 μm (NMO CTRL
= 19/21 and NMO p47
= 16/21). (E) The CFU counts at 1 dpi in notochord infected of p47phox and CTRL morphants (mean number of CFU per larva ± SEM, NMO CTRL = 13 and NMO P47 = 8, Mann-Whitney test, one-tailed, **p<0.01, from three independent experiments). (F) Survival curves of p47phox and CTRL morphants that have been injected with PBS or E. coli in the notochord from 0 to 3 dpi (N is indicated in the figure, log rank test, ***p<0.001, from 4 independent experiments).