Fig. 7

Reception of Hh signaling is not required in neural crest cells to condense on the stomodeum. (A) A tight neural crest cell condensation coats the stomodeum in wild-type 30 hpf fli1:GFP embryos (arrow). (B) The region of this condensation superior to the stomodeum is absent in smo^-;fli1:GFP embryos, although GFP-positive sclera is present surrounding the eye (arrowhead). (C,D) 30 hpf embryos following transplantation between wild-type and smo^- embryos. (C) smo^- neural crest cells readily condense on the stomodeal roof in wild-type embryos (arrow, n=12). (D) Crest cells from wild-type donors fail to condense on the stomodeal roof in smo^- embryos, even though they can populate the region occupied by palatoquadrate and Meckel′s cartilage precursors (n=18). (E-H) Images taken from a time-lapse recording (n=2) of wild-type crest in a smo^- host. Wild-type neural crest cells are capable of initially populating the region superior to the stomodeum (E-H, arrow); however, these cells are not stabilized in this position and eventually migrate posterior to the eye. Wild-type cells in the Meckel′s cartilage domain condense normally (E-G, arrowhead). Lateral views, dorsal is upwards. nc, neural crest; WT, wild type. Scale bar: 50 μm.