Figure 3

Expression of miR-206 is confined to skeletal muscle. Expression of miR-206 (A) is detected by quantitative reverse transcription PCR (qRT-PCR) in tissues isolated from wildtype (WT) (open bars), miR-206/133b knock-out and mdx^y/- (gray bars) mice. Expression of miR-206 is detected in skeletal muscle of the WT mice. miR-206 is not detected in muscles isolated from knock-out mice, confirming the loss of miR-206 in the knock-out tissue and specificity of the Taqman assay. miR-206 was at the qRT-PCR detection limit in heart and brain of WT mice. In WT mice, miR-206 was strongly expressed in the soleus muscle, which has a high content of type 1/oxidative skeletal muscle fibers. A lower amount of miR-206 was detected in the diaphragm, as well as in other skeletal muscles. In mdx mice, the expression of miR-206 was not increased in soleus muscle. Increased miR-206 expression was detected in the diaphragm and other skeletal muscles. Expression of miR-1 (B) was also analyzed in the respective muscles and appeared unchanged in the soleus muscle of miR-206/133b knock-out mice (black bar). Mdx mutation did not cause significant changes in the expression of miR-1. Samples were isolated from ≥3 different animals each, and qRT-PCR was performed in triplicate for each of the samples.