FIG 8.

The Myc 3′ WRE is required for mitogen-induced Myc gene expression. The proliferative regions of colonic crypts were isolated from 7-week-old Myc 3′ WRE^−/− mice and WT littermates and were not treated (Ctrl.) or treated for 1 or 3 h with recombinant Wnt3A, R-spondin1, and EGF (A), Wnt3A and R-spondin1 (B), or EGF (C). RNAs were isolated, cDNAs were synthesized, and Myc expression levels were evaluated by using quantitative real-time PCR. Myc mRNA levels were normalized to β-actin gene levels (n = 3 mice analyzed per genotype, with 12 total PCR replicates per sample). Errors are standard errors of the means (***, P < 0.001).