Figure 4. Reduction in neutrophil counts in zebrafish embryos with decreased s1pr4 expression by morpholino knock–down with two independent morpholino oligonucleotides.

Representative images of zebrafish mpx–gfp fish are shown, demonstrating decreases in neutrophil number in s1pr4 morphants at 2 dpf. (A-C) The top set of panels are composite images of differential interference contrast (DIC), the middle panels are images using fluorescence (green channel), and the bottom panels are black and white images of the fluorescent signal of the same embryo injected at 2 dpf with either (A) non–specific MO, (B) 2 ng/embryo morphlino 1, or (C) 2 ng/embryo morphlino 2; D) distribution of average numbers of neutrophils across s1pr4 MO 1 (n=14), s1pr4 MO 2 (n=19) and non-specific MO (n=22). ****Student t–test p–value < 0.0001. Scale bar represents 300 μm and is the same for all panels.