Fig. 1.

Myogenic miRs. (A) Time course of miR-1 and miR-206 induction during C₂C₁₂ myogenesis. Total RNA from C₂C₁₂ cells in GM or DM for zero (d0), one (d1), two (d2), three (d3), or four (d4) days was subject to Northern blot analysis with a ³²P end-labeled miR-1, miR-206, or U6 probe. ³³P-labeled 10-bp RNA ladder (Ambion) is shown on the left. The miR-1 blot (Top) was stripped and reprobed sequentially for miR-206 (Middle) and U6 (Bottom). Mature and precursor microRNAs are labeled with an arrow and an arrowhead, respectively. (B) Same as in A except that a new set of samples was probed with a ³²P end-labeled miR-133 probe, stripped, and reprobed with a ³²P end-labeled U6 probe. (C) RNA was isolated from growing, undifferentiated primary human myoblasts in SkGM2 proliferation media (U) or from primary human myoblasts differentiated for 2 weeks in 2% horse serum-containing media (D). The position of the microRNA is indicated on the left. The membrane first was probed with miR-1, stripped, and subsequently probed for miR-133, miR-206 and U6 as indicated below the blots. ³³P-labeled 10-bp RNA ladder (Ambion) is shown on the left for the miR-1 blot. (D) Myogenin induction (by using quantitative RT-PCR) in the differentiated sample indicates efficient differentiation of the primary human myoblasts along the skeletal myogenic lineage. The same RNA samples was used for C and D.