Zebrafish gcsf and gcsfr participate in emergency myelopoiesis. (A-F) LPS affects gcsf⁺ and gcsfr⁺ cell populations. Embryos at 48 hpf were injected with 5 μg/mL LPS (+lps) or not (−lps) and fixed 8 hours later, before WISH analysis with either gcsf (A,B) or gcsfr (C,D). Total populations of gcsf (E) and gcsfr (F) were analyzed with mean (dashed red line), 95% CI (solid red lines), and level of statistical significance (*P < .05; **P < .01) indicated. (G-L) LPS effects require gcsfr. Embryos were injected at 1- to 2-cell stage with either scramMo or gcsfrMo1, injected with or without LPS at 48 hpf, and collected 8 hours later, before probing with lyz (I,J). Cell count data of the total populations of lyz⁺ (K) and mpo⁺ (L) cells at 56 hpf were analyzed as described for panels E and F.