tfec acts non–cell-autonomously upon HSPCs. (A) Tol2 construct used to generate transgenic zebrafish; schematic is not to scale. (B) ISH for tfec (common probe) at 24 hpf in flk1:Gal4 positive embryos that were either UAS:tfec negative (upper) or positive (lower). (C) ISH for runx1 at 26 hpf in flk1:Gal4-positive embryos that were either UAS:tfec negative (upper) or positive (lower). (D-E) ISH for cmyb and mpx at 4 dpf in flk1:Gal4-positive embryos that were either UAS:tfec negative (upper) or positive (lower).