Accumulation of HSPCs in the VDA of cmyb^hkz3 mutants. (A-B) Excessive Cd41-eGFP⁺ cells accumulated in the VDA of cmyb^hkz3 mutants. Double staining of Cd41:eGFP protein (top panel) and cmyb RNA (middle panel) in 54-hpf siblings (left panel) and cmyb^hkz3 mutant embryos (right panel) of cmyb^hkz3/Tg(cd41:eGFP) transgenic lines (A). The bottom panel shows merged images. Blue arrowheads in panel A indicate the signal position in the VDA region. Quantification of Cd41-eGFP–positive cells in the VDA region in siblings (yellow columns) and cmyb^hkz3 mutant embryos (blue columns) of cmyb^hkz3/Tg(cd41:eGFP) transgenic lines at 2 dpf (left columns) and 2.5 dpf (right columns; B). Units on the y-axis represent eGFP-positive cell numbers (n ≥ 5, mean ± SD). Asterisks indicate statistical difference with corresponding sibling (t test, P < .05). (C) Quantitative RT-PCR of expression of endothelium and HSPC specific genes in trunk of wild-type (yellow columns) and cmyb^hkz3 embryos (blue columns) at 2 dpf. Expression level was normalized with β-actin expression.