RA restricts the formation of anterior hemangioblasts in zebrafish embryos.

<p>All flat-mounted embryos are positioned anterior left and dorsal front. Embryos were treated with vehicle DMSO (A, D, G, J, M), 50 nM RA from 1–2-cell stage to 14 hpf (B, E, H, K, N) or 250 nM RA from 10 to 11 hpf (C, F, I, L, O), respectively. They were then examined for expressions of <i>pu.1</i> (A–C), <i>scl</i> (D–F), <i>lmo2</i> (G–I), <i>etsrp</i> (J–L), and <i>gata2</i> (M–O) in the rostral end of ALPM at 14 hpf by whole mount in <i>situ</i> hybridization. Expression of <i>myoD</i> in somites is used for staging. Bracket indicates the location of RBI. The number shown in the lower left-hand corner of each panel is the number of embryos exhibiting the typical phenotype shown in the panel to the number of embryos totally observed.