Fig. 2.

Not only Sulf1A but also MyoD is undetectable in quiescent satellite cells (0 h) but reactivated in these cells in vitro, in normal culture medium or in the presence of Lac-Z transfected (control), and Wnt1 and Wnt6 secreting cells. Satellite cells on single fibres were cultured in the presence of Lac-Z-transfected control cells (C), and Wnt1 and Wnt6 secreting cells for 13, 24, 48 and 72 h before staining for MyoD and Sulf1A using double immunofluorescence procedure. Satellite cells at 13, 24 and 48 h are shown as a single image with superimposed image of both Sulf1 and MyoD while individual images for Sulf1A and MyoD are shown for 0 and 72 h time points; h: hour. Individually spaced single satellite cells on freshly isolated muscle fibres gradually develop into small clusters in normal culture medium while the cluster size is increased in the presence of Wnt1 exposure. Wnt6 in contrast shows little or no proliferation but a marked change in cell morphology indicating its inhibitory action on growth.