Fig. 4.

Myeloid marker expression analysis at 24 hpf. HCR analysis for expression of the pan-myeloid marker lcp1 (A-C), the neutrophil marker lyz (D-F) and the macrophage marker mpeg1.1 (G-I) in fli1b^+/− control and fli1b^−/− mutant embryos. Two populations of lcp1⁺ GFP⁺ (or lyz⁺ GFP⁺ or mpeg1.1⁺ GFP⁺) and lcp1⁺ GFP⁻ (or lyz⁺ GFP⁻ or mpeg1.1⁺ GFP⁻) were observed. Boxed areas are shown at a higher magnification in the upper right inserts. White arrowheads show GFP⁺ myeloid cells, whereas yellow arrowheads show GFP⁻ myeloid cells. Only myeloid cells located at the yolk surface were quantified. Note that the number of GFP⁺ myeloid cells was significantly increased in fli1b^−/− embryos, whereas the number of GFP⁻ myeloid cells was reduced. Myeloid cell GFP expression was faint in fli1b^+/− embryos and much brighter in fli1b^−/− embryos; both weak and strong GFP⁺ cells were included in GFP cell counts. Bars show mean±s.d. ****P<0.0001; Student's two-tailed unpaired t-test.