Characteristics of placental-specific DMRs. (A) The proportion of known imprinted germline DMRs, placental-specific DMRs, and CGIs with one or more ZFP57 binding site consensus sequences is shown. (B) Enrichment for H3K9me3, using 1000-bp sliding windows with a 1000-bp step, was compared between human placenta and fetal muscle. Using the absolute difference for each probe, placental-specific DMRs (P = 2.2 × 10−16, t-test) and CGIs (P = 2.2 × 10−16, t-test) showed a significant enrichment compared to all other probes, in placenta. Placental-specific DMRs were not significantly different from CGIs (P = 0.70, t-test). (C) Expression of genes associated with placental-specific DMRs based on closest transcription start site (Supplemental Table 6) is shown in TE, and 2nd and 3rd trimester placental villi.
