Homo sapiens Epigenomics. Homo sapiens

We performed whole genome bisulfite sequencing (WGBS) to characterize the methylome of ccf DNA from eight non-pregnant and seven pregnant female donors. In addition, seven genomic DNA samples isolated from maternal buffy coat and five placenta samples were sequenced at single base resolution. This produced DNA methylome maps for each sample type. The present study provides single-base resolution methylomes of ccf DNA, demonstrates a link between local DNA methylation levels and ccf DNA fragment size, and shows large, continuous regions of hypomethylation in the placenta (Placenta Hypomethlated Domains or PHDs), an epigenetic phenomenon, until recently, only described in tumor samples.