Figure 4.

 Northern blot analysis for the change in mRNA in postnatal myocardium. Seven genes (cyclin B1, PCNA, IGF-II, MEK4/SEK1, HMGCoA synthase, ARL-6, and S-adenosylmethionine decarboxylase 3) with descending expression profiles and three genes (caeruloplasmin, TB2 protein-like 1, and neuronal protein 3) with ascending profiles were used to demonstrate the validity of the microarray results. GAPDH and 18S/28S were used as the internal control and for RNA quantitation. Each gene has been sequence verified. Similar results were obtained in three independent experiments.