flt3 mRNA rescue and flt3 knockdown had no effect on angiogenesis and vasculogenesis. The expression of c-myb (A) and rag1 (B) in uninjected control, flt3MO, and flt3MO + flt3 mRNA injected embryos at 4 dpf. The arrowheads in panel Ai and the arrow in Bi indicated c-myb (CHT region) and rag1 (thymus) expression. (C) The development of ISV, DA, and DV in control and flt3MO embryos at 24 hpf. (D) flt4 (DV) and efnb2α (DA) expression in control and flt3MO embryos at 32 hpf. Panel Ai-iii represents the whole mount in situ hybridization of c-myb in control (Ai), flt3MO (ii), and flt3MO rescue (iii) embryos at 96 hpf, respectively. Panel Bi-iii represents the whole mount in situ hybridization of rag1 in control (Bi), flt3MO (ii), and flt3MO rescue (iii) at 96 hpf, respectively. Panel Ci-iv represents the green fluorescence (indicates the flk1 expression) in control (Ci and iii), and flt3MO (ii and iv) embryos at 24 hpf, respectively. Panel Di-iv represents the flt4 (Di and ii) and efnb2α expression in control (Di, iii) and flt3MO (ii, iv) at 32 hpf, respectively. Scale bars represent 250 μm.