DAN perturbations are consistent with BMP signaling. (A) HH St 15 embryo in which neural crest cells are transfected with BMP2 MO. (B) HH St 15 embryo in which neural crest cells are transfected with control MOs. (C) Area of the branchial arch region containing neural crest cells. n = 21 BMP2 MO embryos; n = 8 control MO embryos. (D) Distance migrated by neural crest into ba2. n = 21 BMP2 MO embryos; n = 8 control MO embryos. (E) HH St 15 embryo labeled with HNK-1 (green) and pSMAD (red). (F) Same embryo as in E but with pSMAD only. Dotted lines represent neural crest cells within (asterisks) and through (o) the DAN-rich region. Bars, 50 µm. (G) Intensity of pSMAD antibody stain within and through DAN. n = 8 embryos. Two-sided Student’s t test. OV, otic vesicle.