Fig. 6. Sca-1 is expressed on a subpopulation of primary murine skeletal myoblasts. Flow cytometry of primary myoblasts isolated from the hindlimbs of C57BL/6 mice and cultured in differentiation medium (DM) for at least 3 days demonstrated that a subpopulation of Sca-1-positive cells and small myotubes, constituting 25% of selected myoblasts at the time of isolation, decreased in number with differentiation and expression of myosin (top). Of particular note, Sca-1 expression in this residual population of Sca-1 expressors increased on a per cell basis (middle), whereas the size of these cells, as a function of forward angle light scatter (FALS), remained constant (bottom). All data points are shown. Trendlines were generated by bivariate regression analysis using the Pearson coefficient with significance levels indicated.