library_construction_protocol: Genomic DNA was isolated from the samples using the Beckman Coulter's Agencourt RNAdvance Cell v2 kit following the manufacture's instructions. Post-bisulfite adaptor-tagging libraries for whole-genome DNA methylation analysis were prepared from purified genomic DNA as previously described (von Meyenn et al., 2016; Miura et al., 2012; Smallwood et al., 2014). PBAT libraries were prepared by bisulfite converting Proteinase K digested cell lysates using the EZ DNA Methylation-Direct Kit (Zymo). After cleanup, 1st strand synthesis was performed using 6N-forward oligos at 37°C for 90 minutes. Subsequently, samples were treated with Exonuclease I for 1 hour at 37°C, and DNA was purified using AMPure XP beads (Agencourt). Samples were eluted in 2nd strand synthesis mix with 6N-reverse oligos and incubated at 37°C for 90 minutes. DNA was purified and amplified with KAPA HiFi HotStart DNA Polymerase (KAPA Biosystems). All amplified libraries were purified and assessed for quality and quantity using High-Sensitivity DNA chips on the Agilent Bioanalyzer. Paired-end sequencing was carried out on HiSeq 2500 instruments (Illumina).