Figure 1. Metastable and imprinted genic regions.

(A) Metastable epiallele loci, A^vy and Cabp^IAP, are caused by the insertion of an IAP element (green lines) containing variably methylated CpGs (sites labeled 1–4) in the LTR region (red lines). (B) Imprinted loci, Igf2 and Igf2r, contain multiple differentially methylated regions (red lines) whose methylation status is dependent on the parent of origin. Assayed CpG sites are in red text. Primer locations are underlined; see Table 1 for primer sequences for bisulfite converted DNA. The sequencing primer location is in blue text.

A^vy: Viable yellow agouti; Cabp^IAP: CDK5 activator-binding protein intracisternal A particle element; Chr: Chromosome; DMR: Differentially methylated region; IAP: Intracisternal A particle; LTR: Long terminal repeat.