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Fig. 7
Wnt/β-catenin signaling is required for extra neuromast formation in the absence of ErbB signaling.
To block Wnt/β-catenin signaling wild type or Tg(sox10:DNerbb4) fish were treated with two different inhibitors IWR-1 or XAV939 for 24 hr starting at 32 hpf. Neuromast number up to somite 14 was counted at 3 dpf (A). Compared to DMSO, both IWR-1 and XAV939 significantly inhibited neuromast formation in Tg(sox10:DNerbb4) (A, red bars, One-way ANOVA with Tukey pairwise comparison, pd0.05). Representative images of alkaline phosphatase stained control siblings treated with DMSO (C), IWR-1 (E) or XAV939 (G) or Tg(sox10:DNerbb4) treated with DMSO (D), IWR-1 (F) or XAV939 (H). (B) Neuromast counts at 3 dpf of control, Tg(sox10:DNerbb4), Tg(hsp70l:dkk1b) or Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b) after heat shock at 32 hpf. Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b) double transgenics show a complete loss of extra neuromast formation seen in Tg(sox10:DNerbb4) (B, Student’s t-test, p=2.4E16). Representative images of alkaline phosphatase stained sibling (I), Tg(sox10:DNerbb4) (J), Tg(hsp70l:dkk1b) (K) or Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b) (L) at 3 dpf. The first deposited neuromast is to the left for all alkaline phosphatase images.