Fig. 3. Overexpression of HDAC4 inhibits cardiomyogenesis. P19(control) and P19(HDAC4) cell lines were aggregated in the presence of DMSO and total RNA was harvested on days 0, 3 and 6. (I) Northern blot analyses of 12 µg of total RNA from P19(control) and P19(HDAC4) cells probed as indicated on the right. (II) Total RNA was reverse-transcribed and PCR products for Nkx2-5 were detected by Southern blot analysis. Lanes were spliced from the same autoradiogram.