The effects of calycosin treatment on blood vessel formation in SIVs of <i>Tg(fli1:EGFP)</i> zebrafish embryos.

(A) Control: embryo treated with 0.1% DMSO at 96 hpf, SIVs appear as a smooth basket-like structure. (B–D) Calycosin: embryo treated with 10, 30, 100 µM calycosin at 72 hpf for 24 h, leads to enlarged SIV basket stretching into the posterior yolk extension. (a–d) Enlarged SIV region (×4.5) of A–D respectively. White arrows indicating the enlarged vessels, yellow and red arrows indicate sprouting and intersectioning branches respectively. (E) Calycosin increases SIV diameter in a dose-dependent manner. Data are plotted as mean±SEM, (n = 3), *P<0.05, #P<0.001.