FIG 7.

The Myc 3′ WRE is required for proper regulation of Myc gene expression in purified colonic crypts. (A) Relative levels of Myc mRNA, as assessed by quantitative reverse transcription-PCR, in purified colonic crypts from WT and Myc 3′ WRE^−/− mice. (B) Schematic of the Myc gene locus, with its position on chromosome 15 indicated above and the Myc 5′ and 3′ WREs represented as white rectangles. Gray rectangles indicate the positions of the amplicons produced in the PCRs. (C to G) Colonic crypts were isolated from 7-week-old Myc 3′ WRE^−/− mice and WT littermates and fixed in formaldehyde. ChIP assays were conducted by using the antibodies indicated, and the precipitated DNA was measured by using specific oligonucleotides to produce the indicated amplicons in quantitative and real-time PCR assays. Control primer sets 1 and 9 were used to monitor the level of background in the ChIP assays. In panels A and C to G, 3 mice per genotype were examined, with 12 total PCR replicates per sample. Errors are standard errors of the means (*, P < 0.05; **, P < 0.01; ***, P < 0.001).