Stage-dependent requirements for Bmp. (A–E, G–L) Analysis of indicated gene expression patterns in control embryos and embryos treated with 100 µM dorsomorphin (DM) at 5 hpf or 7 hpf. Lateral views with dorsal to the right and anterior up. Expression of six4.1, eya1 and dlx3b (A–C) in PPE, krox20 in hindbrain(D) and p63 in epidermal ectoderm (E). Expression of competence factor genes tfap2a, tfap2c, foxi1 and gata3 (G–J). Reporters of Bmp-signaling, Phospho-Smad1/5/8 antibody staining (K) and sizzled in situ hybridization (L). Note the complete loss of Bmp signaling by 100 µM DM-treatment either at 5 hpf or 7 hpf. (F) Lateral views of live embryos at 30 hpf. Embryos treated with DM at 7 hpf show a partially dorsalized C3 phenotype [33]. (M, N) Tg(hs:chd) and/or Tg(hs:dnBmpr) embryos heat-shocked and treated with 100 µM DM at 7.5 hpf. eya1 expression (M) and C3 phenotypes (N) are comparable to embryos treated with 100 µM DM alone.
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