FIG. 1.

Differential expression of p18 mRNA during C2C12 cell differentiation. (A) Total RNA was prepared from proliferating C2C12 cells cultured in growth medium (lane 1) or in differentiation medium for the time indicated above each lane (lanes 2 to 9). Ten micrograms of each RNA sample was resolved on a 1% agarose–formaldehyde–MOPS gel, transferred to a nitrocellulose filter, and hybridized with a probe derived from the coding region of mouse p18 cDNA (top). The same blot was stripped and rehybridized with a probe derived from the mouse myogenin gene to monitor the progression of myogenesis (middle). Approximately equal amounts of RNA were loaded, as determined by ethidium bromide staining (bottom). (B) Expression of p18 exon 1 during C2C12 cell differentiation. Ten micrograms of total RNA prepared from C2C12 cells cultured in growth medium (lane 1) or in differentiation medium for the time indicated above each lane (lanes 2 to 9) were resolved on a 1% agarose–formaldehyde–MOPS gel, transferred to a nitrocellulose filter, and hybridized with a probe derived from exon 1 of NIH 3T3 cDNA clone T9 (top). Approximately equal amounts of RNA were loaded, as determined by ethidium bromide staining (bottom).