FIGURE 3

Effects of shSCA1 and miSCA1 on miR-1 function in differentiating myoblasts. (a) Cartoons depicting the miR-1 luciferase reporter (contains a perfect complementary miR-1 target site in the 3'UTR of Firefly luciferase) and the RNAi-hrGFP dual expression vector used in C2C12 studies. (b) Disruption of endogenous miRNA biogenesis and function was assessed in C2C12 cells which show induced miR-1 expression after differentiation. Cells were co-transfected with RNAi and miR-1 luciferase reporter plasmids, and then differentiated. Each group (n = 4) was normalized to cells treated with siCheck2-alone (i.e., no miR-1 target), and the results are shown as mean values SEM. No RNAi (---) served as the empty-vector control. (c) RNAi plasmids co-expressing hrGFP were co-transfected into C2C12 cells, and these were differentiated and stained for myosin heavy-chain (MHC) to identify transfected differentiating myotubes (i.e., hrGFP+/MHC+). (d) The lengths of hrGFP+/MHC+ cells were measured, and the results (mean values SEM) are shown as fold-elongation relative to undifferentiating cells (n indicated in parentheses, **P < 0.01).