FIG. 4.
Model depicting the Rasgrf1 DMD and repeat as a binary switch that regulates Rasgrf1 imprinting. Shown are the putative neonatal enhancer (Enh), promoter (Pro), repeats (rightward-pointing filled triangles) and the DMD methylated (filled circles) and unmethylated (open circles) on the paternal and maternal alleles, respectively. Curved lines ending in an X indicate blocked interactions or activities, and lines ending in an arrowhead indicate those that are permitted. The repeat-deficient Rasgrf1 allele (Rasgrf1tm1Pds) was described earlier (29). See the text for details.