Fig. 7
Canonical Wnt signaling is necessary for Etv2-induced transdifferentiation of muscle fibers.
(A) Inhibition of Wnt signaling using XAV939 or heat shock–inducible, dominant negative Tcf3 (hsp70l:tcfΔC-EGFP) blocks Etv2-induced kdrl:GFP expression. However, activation of Wnt signaling using CHIR99021 or heat shock–inducible, constitutively active β-catenin (hsp70l:caβ-catenin-2A-TFP) also blocks Etv2-induced kdrl:GFP expression. (B) XAV939 dose dependently inhibits Etv2-induced kdrl:GFP expression. Kdrl:GFP expression was quantified by counting the number of GFP+ myotomes with a myotome being considered positive if >3 muscle fibers within a given myotome were GFP+. (C) CHIR99021 dose dependently inhibits Etv2-induced kdrl:GFP expression. (D) XAV939 (40 μM) inhibits Etv2-induced kdrl:GFP expression independent of heat shock time, while CHIR99021 (50 µM) inhibits at 22 and 24 h heat shocks, has no effect at 26 h heat shock, but enhances Etv2-induced kdrl:GFP expression at 28 h heat shock. For all data t test was used for statistical comparisons with (*) p<0.05 and (**) p<0.01.