Parent-of-origin dependent DNA methylation and gene expression in the human placenta

DNA methylation is globally reprogrammed after fertilization and the parental genomes have similar DNA methylation profiles after implantation except at the germline differentially methylated regions (gDMRs). We, and others, have previously shown that there are a large number of transient gDMRs in human blastocysts, whose differential methylation is lost in embryonic tissues after implantation. In this study we employed genome-wide allelic DNA methylation analyses of highly purified trophoblast cells from human placentas. ~40% of the transient-in-embryo gDMRs maintained their parent-of-origin-dependent biased allelic methylation. RNA sequencing-based allelic expression analyses revealed that some of the placental-specific gDMRs were associated with novel imprinted genes. This approach identified the first examples of X-linked gDMRs specific to the placenta. These findings highlight the unique regulation of allelic DNA methylation in the human placenta, which is important for understanding normal placental development and the pathogenesis of pregnancy complications.

• Type: Whole Genome Sequencing
• Archiver: Japanese Genotype-phenotype Archive (JGA)