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Fig. 8
Wnt/β-catenin signaling is required for proliferation of interneuromast cells in the absence of ErbB signaling.
Control sibling, Tg(sox10:DNerbb4), Tg(hsp70l:dkk1b) or Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b), all with Tg(SqET20:gfp) in the background, were heat shocked at 32 hpf then placed in BrdU solution. Fish were fixed at 48 hpf and processed for BrdU and GFP immunohistochemistry (A–D). Compared to control siblings (A), Tg(sox10:DNerbb4) (B) show a strong increase in BrdU incorporation into Tg(SqET20:gfp) positive interneuromast cells. BrdU incorporation in Tg(sox10:DNerbb4) is blocked by over expression of Dkk1b (D). (E) Quantification of BrdU index shows no difference between control and Tg(hsp70l:dkk1b) (Student’s t-test, p=0.6) but a large decrease between Tg(sox10:DNerbb4) and Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b) (Student’s t-test, p=3.4 E8). (F) Quantification of Tg(SqET20:gfp) cell number again shows no difference between control and Tg(hsp70l:dkk1b) (Student’s t-test, p=0.14) but a large decrease between Tg(sox10:DNerbb4) and Tg(sox10:DNerbb4)/Tg(hsp70l:dkk1b) (Student’s t-test, p=1 E4).