Genomic DNA from hESC and hPGCLC were extracted with Quick-DNA mini prep kit (Zymo Research, Cat# D3025). tion was carried out using EZ DNA Methylation-Direct™ Kit (Zymo Research Cat# D5020).  After bilfite conversion, the samples were prepared for Illumina sequencing using the Accel Methyl-NGS kit (Swift Biosciences).