Fig 3

Fig 3 Wnt components are modified in taz^-/- mutants and inhibition of

β-catenin mediated transcription results in reduced ventricle size. (A) in situ hybridization of wnt1 shows that in wild-type animals wnt1 expression is seen as striations along the hindbrain ventricle. In taz-/- mutants, this expression is disorganized. (B) Wild-type embryos were treated with 200 µM ICG-001 and 100 µM Windorphen to inhibit β-catenin mediated transcription. Compared to DMSO controls, treated embryos show reductions in ventricle size. (C) Similarly, inhibition of β-catenin mediated transcription via injection of 10 pg of a drTCF3 resulted in a reduced ventricle size compared to controls injected with eGFP alone. Cell nuclei labelled with TO-PRO-3. (D) Compared to wild-type animals, treatment with 5 µM XAV939 reduced ventricle size as visualized using atoh1a in situ (top). Additionally, XAV939 treated animals show a reduction of Taz protein localization at rhombomere boundaries (bottom). Cell nuclei labelled with TO-PRO-3. (E) Animals treated with 10 µM SB216763 show little change to ventricle shape and size compared to wild type animals, visualized using atoh1a in situ (top). However, SB216763 animals show an increase in Taz signal throughout the rhombomere, as seen more clearly in the black and white images of SB216763 treated animals included. Cell nuclei labelled with TO-PRO-3. (F) Treatment with 10 µM SB216763 results in 75% increase in fluorescence (P-value ≤  0.001) within rhombomeres, and an increase in fluorescence of 145% at rhombomere boundaries (P-value ≤  0.001). (G) Wild-type embryos were treated with 200 µM ICG-001 and 100 µM Windorphen to inhibit β-catenin mediated transcription. Compared to DMSO controls, treated embryos show reductions in ventricle size. Compared to DMSO controls, treated embryos show little to no reduction in Taz immunofluorescence. Scale bars =  100 µm.