Establishment of genomic imprints during early development involves concerted epigenetic mechanisms. Two recent studies by Terranova et al. (in this issue of Developmental Cell) and Pandey et al. (in a recent issue of Molecular Cell) have demonstrated that Polycomb group proteins (PcG) and the Kcnq1ot1 regulatory RNA, respectively, are indispensable for gene- and lineage-specific chromatin modification and compaction of the paternally imprinted Kcnq1 cluster.