FIG. 3.

Expression of murine Runx3 transcripts. (A) Schematic representation of Runx3 exon structure and derived RNA transcripts. Solid boxes represent exons 1 to 6, and open boxes indicate 5′ and 3′ untranslated sequences. Exon 1- and exon 5-specific probes are indicated by hatched and grey boxes, respectively. (B) Northern blot analysis of 20 μg of total RNA from T1i, T14i T29i, T48i, T82i, T85i, and EL4 cells and from control nontransgenic thymus (Thy) was performed using Runx3 probes, exon 1 (upper) and exon 5 (lower), and GAPDH to control for RNA loading. The blot was hybridized sequentially with the exon 1, exon 5, and GAPDH probes, with stripping between hybridizations. The exon 1 probe detects only those transcripts derived from the P1 promoter, whereas the exon 5 probe detects both P1- and P2-derived transcripts. (C) Graphic representation of expression levels of P1-specific transcripts normalized with respect to GAPDH expression.