DNA from placental tissue was extracted using QIAamp DNA mini kit (Qiagen) following the manufacturer’s protocol. Genomic DNA was digested with MspI (New England Biolabs, Ipswich, MA) followed by end repair and addition of 30 A overhangs. Methylated adaptors (Illumina, San Diego, CA) with a 30 T overhang were then ligated with the generated fragments. Following adaptor ligation, DNA fragments ranging from 40 to 220 bp (preligation size) were cut from a 3% (w/v) NuSieve GTG agarose gel (Lonza, Basel, Switzerland) and subsequently bisulphite modified using the EZ DNA methylation kit (Zymo Research, Irvine, CA). The final library was amplified by PCR. The resulting library was sequenced on an Illumina platform with a single-ended, 100bp run.
GEO Accession
GSM1463090