Fig. 9

Crosstalk of Wnt and Hh signalling in swimbladder development.

(A–C) Expression of shh (A), ihh (B) and ptc1 (C) in swimbladder of controls at 72 hpf. These controls were heat-shocked at 66 hpf and fixed at 72 hpf prior to WISH. (D–F) Decreased expression of shh (D), ihh (E) and ptc1 (F) in swimbladder of hs:Dkk1-GFP fry after heat-shock. (G–I) Expression of axin1 in wild type (G), smo^b641 (H) and syu^t4 (I) at 72 hpf. (J–L) Expression of axin2 in wild type (J), smo^b641 (K) and syu^t4 (L) at 72 hpf. Embryos in (G–L) were short-stained for the same one hour for comparison and no detectable axin1 and axin2 signals were observed in controls but prolonged staining (5 hours) showed enriched hybridization signals in the swimbladder in controls (G′ and J′). Compared to the short-staining pictures in (G) and (J), increased global expression of axin1 and axin2 in smo^b641 and syu^t4 was observed although the swimbladder development has been severely affected in the two mutants [26]. Red arrows indicate the position of swimbladder. Abbreviation: sb, swimbladder. Scale bar in (A) = 200 μm for all panels.