Construction of recombinant CVB3 and detection of endogenous specific miRNA. (A) Cognate target sequences for miR-133 and/or miR-206 were inserted into different locations of the CVB3 genome; location 3 in the figure was chosen. (B and C) Endogenous muscle-specific miR-206 and miR-133 expression in TE671, L6, and HeLa cells. The average concentrations of miR-206 in TE671 and L6 cells were 4.49 × 108 and 5.46 × 108 copies in 104 cells, values significantly higher than those observed in HeLa cells, i.e., 3.06 × 104 copies in 104 cells; the differences in the miR-133 average concentrations in TE671, L6, and HeLa cells were not significant, i.e., 1.36 × 104, 2.93 × 104, and 8.7 × 103 in 104 cells, respectively. *, P < 0.01 for miR-206 concentrations in TE671 and L6 cells compared to HeLa cells.