Phenotype and circulation defect of β-lapachone-treated embryos. Embryos at 24 hours post-fertilization (hpf) were treated with DMSO or β-lapachone for 4 h and examined at 30 (A, B), 52 (C-F), 72 (G-J), and 96 hpf (K, L). Dextran rhodamine dye-injected and DMSO-treated 48-hpf embryos 2 min after dye injection (M, N), and dextran rhodamine dye-injected β-lapachone-treated 48-hpf embryos 2 min (O) and 16 min after dye injection (P) are shown. Arrowheads indicate erythrocytes. The star indicates yolk edema. Black arrows point to the linear arrangement of the heart chambers and pericardial edema, while white arrows in panels N-P indicate dye injection sites. Scale bars represent 100 μm.