Fig. 4

ErbB signaling is required during neural crest migration. Control embryos and embryos treated with AG1478 for various time periods were labeled with Elavl antibody at 4 dpf to examine DRG formation. (A-F) Somites 4-18 of inhibitor-treated (A,C,E) and control (B,D,F) embryos. DRG neurons were missing between somites 5 and 11 when embryos were treated from 8-14 hpf (A) and DRG neurons were missing throughout the body when embryos were treated from 18-30 hpf (C). DRG neurons were present anteriorly but missing posterior of somite 13 when embryos were treated from 24-30 hpf (E). DRG neurons were present in all segments in control embryos. Arrowheads in A, C and E indicate DRG neurons. (G,H) Graphs showing average percentage of fish with DRG neurons at each of three axial levels when embryos were treated for various time periods. In control embryos, DRG neurons were present in 90-100% of fish for all experiments. At least 30 embryos were counted in each experiment. Scale bar: 50 μm.