Fig. 3. ß-catenin activation of Myf5 expression in PSM and somite explants. (A-F) PSM explants (A-C) and somite explants (D-F) infected with a lentiviral vector carrying the cDNA for a stabilized form of ß-catenin (Dp). (A,D) Hoechst staining of the nuclei. Infected cells were visualized by GFP fluorescence (B,E), and Myf5^nlacZ/+-expressing cells were detected by immunofluorescence with an anti-ß-galactosidase monoclonal antibody (C,F). (G,H) Quantitative analysis of Myf5^nlacZ activation in infected PSM (G) and somite (H) explants. Explants were infected with Dp or C ß-catenin lentiviruses and co-cultured with or without 2 nM N-Shh recombinant protein (Shh). Explants co-cultured with neural tube (NT) were used as a positive control; explants infected with lentiviruses carrying GFP cDNA only were used as a negative control (C). Independent experiments (n=8) were performed in triplicate and averaged.