Figure 1

Expression of myogenic differentiation markers and miRNA profiling. A. Expression of muscle differentiation markers MYOG (myogenin, myogenic factor 4, p-value=0.0016), TNNT1 (Troponin T type 1, skeletal slow, p-value=0.00064), MYL4 (myosine light chain 4, p-value=0.0016), COL15A1 (collagen, type XV, alpha 1, p-value=0.013), TNNT2 (troponin T type 2 (cardiac), p-value=4.8x10^-6), VIM (vimentin, p-value=0.00034), ID1 (inhibitor of DNA binding 1, p-value=1.9x10^-5) and CAV1 (caveolin 1, p-value=0.00015) in proliferating myoblasts (labeled as P) and differentiated myotubes (labeled as D) was measured using qRT-PCR, normalization was performed using ΔΔCt method using GAPDH as a control gene and proliferating sample #1 as a reference sample (expression level 1). The average of three independent experiments is shown. Numbers from 1 to 6 indicate the sample number (for full description refer to Table S1). Insets indicate the average of 6 samples of proliferating myoblasts (P) and differentiated myotubes (D). Asterisk corresponds to p-values<0.05. Error bars correspond to standard deviation (SD) in the case of individual samples and standard error of the mean (SEM) in the case of average expression levels (inset). B. Results of immunofluorescence microscopy analysis of cells stained with anti-Ki67 (red), and anti-Desmin (green) antibodies and DAPI nuclear staining (blue) showing normal cellular localization of these proteins in proliferating myoblasts and differentiated myotubes, 20x magnification. Bar=10 μm. C. The number of Ki67+ cells is significantly reduced during myogenic differentiation in vitro. Results of quantification of the DES+ and Ki67+ cells representing 300 individual cells. Statistically significant difference between cell cultures of proliferating myoblasts and differentiated myotubes is indicated by an asterisk (t-test p-value<0.05).