Figure 1
From: Genomic imprinting mechanisms in embryonic and extraembryonic mouse tissues
Three examples of mouse imprinted gene clusters showing imprinted expression in the embryo and/or adult versus placenta. (a) Igf2r cluster: imprinted silencing on the paternal chromosome is initiated by the Airn macro ncRNA. (b) Kcnq1 cluster: imprinted silencing on the paternal chromosome is initiated by the Kcnq1ot1 macro ncRNA. (c) Igf2 cluster: imprinted silencing on the maternal chromosome is initiated by CTCF binding the unmethylated ICE forming an insulator that blocks access to enhancers. Protein-coding genes and ncRNAs showing imprinted expression are shown as pink (maternally expressed) and blue (paternally expressed), with genes showing no parental allelic difference in gray. ICE, imprint control element; M, DNA methylation; and E, enhancer.
