Fig. 5

DNA methylation state at DMRs. A Schematic diagram of mouse Igf2r/Airn locus: solid boxes are represent Igf2r exons, and location of DMR1 and DMR2. 12 and 13 CpG dinucleotides were analyzed. Open circles indicates CpG islands. The methylation boundary in oocytes was marked by red asterisk. B DNA methylation profiles of Igf2r DMR1 in mouse blastocysts. The analyzed region contains 12 CpG sites. Per ‘mini-array’ indicates one blastocyst and six clones were sequenced for each array of the group. C DNA methylation profile of Airn DMR2 in mouse oocytes. The analyzed region contains 13 CpG sites and five clones were sequenced for each array. D DNA methylation profile of Airn DMR2 in mouse blastocysts. The analyzed region contains 13 CpG sites and five clones were sequenced for each array of the group. Open circles indicate unmethylated CpG sites and filled circles indicate methylated CpG sites. Missing circles are represent CpG sites whose methylation status could not be determinate. Horizontal lines represent one individual clone. Lollipop diagrams were generated using BIQ Analyser software. E Summary schematic depiction on dynamic regulation of Igf2r/Airn in preimplantation embryo. In ICSI control blastocysts, Igf2r is expressed biallelically (dashed arrow) and Airn is silent. The DMR1 is unmethylated on both parental alleles. The DMR2 is methylated on the maternal allele and unmethylated on the paternal allele. In AOA treatment ICSI blastocysts, maternal methylation at DMR2 spreads, followed by initiation of paternal Airn transcription. Igf2r is up regulated expression on the maternal allele (thick green arrow), but the up-regulation is blocked on the paternal allele by Airn transcriptional interference in cis