Figure 1.

Genetic deletion of the miRNA pathway induces the gene cluster “focal adhesion” in proliferating primary myoblasts. A. Myoblast cultures (Pax7^CExDgcr8^flox/flox) were incubated for 48 h with tamoxifen to induce Cre recombinase (Dgcr8 KO) or with vehicle (Control). Deletion of Dgcr8 induced a time-dependent decrease of DGCR8 protein (western blotting), miRNA levels (qRT-PCR normalized for sno234, n = 4, control represented by the dashed line) and onset of apoptosis (flow cytometry for annexin V staining, n = 6–11). B. Primary myoblasts were treated as in A and differentiated into myotubes for 48 h four days after the beginning of the tamoxifen incubation (day 4). Desmin (green), nuclear DAPI ((blue), 20× magnification, scale bar = 50 μm. C. KEGG pathway analysis of RNA isolated from proliferating Dgcr8 KO and control myoblasts at day 4. D. Expression of Dcgr8 and members of the KEGG pathway “focal adhesion” in Pax7^CExDgcr8^wt/wt (control) and Pax7^CExDgcr8^flox/flox myoblasts measured using qRT-PCR at day 4 after tamoxifen incubation, n = 4. The dashed line represents incubation with vehicle. All results are shown as mean ± SEM. ∗: p < 0.05, ∗∗: p < 0.01, ∗∗∗: p < 0.001, student's t test.