design: Briefly, a 200-ng genomic DNA sample was sheared to about 300-bp                 fragments by sonication. Then DNA fragments were subjected to end-repair, addition                 of adenosine to the 3 end, and TruSeq adaptor ligation (Illumina, San Diego, CA                 USA). Bisulfite conversion was implemented via the EZ DNA methylation kit (Zymo                 Research, Irvine, CA USA) according to the manufactures protocol. After that,                 bisulfite-converted DNA was enriched through several cycles of PCR amplification                 using the KAPA HiFi HotStart uracil DNA polymerases (Kapa Biosystems, Boston, MA                 USA). Finally, 150-bp pair-end sequencing was conducted on the Illumina X Ten                 sequencing platform.