Figure 4.—

Promoter methylation. DNA from C2-W22, C2-Idf, and C2-Idf/C2-W22 heterozygotes was digested with the methylation-insensitive enzyme NdeI. Samples were then digested with methylation-sensitive enzymes. (A) A diagram of restriction sites assayed. Open circles represent unmethylated sites and solid circles represent methylated sites. Because the 3′-most HinfI site is located very close to the 3′ NdeI site, its methylation status could not be determined by Southern analysis. (B) Representative Southern blot probed with the c2 promoter.