Fig. 1.
Regulation of imprinted expression at the human and mouse H19/Igf2 loci. Shown is the organization of the mouse (top) and human (bottom) locus (not drawn to scale). Genomic positions in base pairs based on NCBI build 36 (humans) and 37 (mouse). CTCF target sites (designated as CTSs in human and shown with black bars) are indicated within the ICR/DMD/IC1 (yellow bar). (A) Methylation status and gene expression are shown for the mouse H19/Igf2 locus. Arrows at genes denote active status while arrows pointing right to left denote interactions between enhancers and gene promoters. (B) Microdeletions at IC1 in BWS patients are denoted by hatched-marked bars (modified from [133]). See text for references. The CTSs that are deleted in each case are represented in parenthesis beside each deletion. The corresponding methylation status of the maternally inherited allele for each deletion is depicted to the right as unmethylated (open lollipops), methylated (filled lollipops) or partially methylated (half-filled lollipops).