Uninjected control embryos (A–D) or embryos injected with dazap2 mRNA (250pg, one cell at 4-cell stage) (co-injected with lacZ mRNA, A’-D’) were treated with either DMSO (1%, carrier control) or SU5402 (80μM) at stage 12. Stage 18 embryos are shown in dorsal views, with anterior at the top. Uninjected embryos show no change in sox2 expression after SU5402 treatment (B), in contrast, hoxb9 expression was strongly reduced (D) in treated embryos, when compared to sibling controls (A and C, respectively). Dazap2 mRNA injected embryos show both an expansion (arrow) of sox2 expression (A’ and B’) and ectopic (arrowhead) expression hoxb9 (C’ and D’) when treated with either DMSO or SU5402.