Accumulation of Cd41-eGFP⁺ HSPCs in cmyb^hkz3 mutants is not caused by enhanced HSPC formation or proliferation. (A) WISH of runx1 expression in the VDA region in the 30-hpf sibling (top panel) and cmyb^hkz3 mutant (bottom panel) embryos. Arrows identify runx1-positive cells in the VDA. (B) Counts of runx1-positive cell in 30-hpf sibling and cmyb^hkz3 mutant embryos (n ≥ 6, mean ± SD). (C) Profiling of BrdU incorporation by VDA Cd41-eGFP⁺ cells in cmyb^hkz3/Tg(cd41:eGFP) mutants and their siblings by double staining of BrdU and cd41:eGFP. Green indicates eGFP; red, BrdU; a, aorta; and v, vein. Circled (white) regions are the VDA regions. (D) Statistical data showing the percentage of VDA localized Cd41⁺ HSPCs that incorporate BrdU (n ≥ 7, mean ± SD).