DNA was extracted by adding equal volume of buffered phenol:chloroform:isoamyl alcohol (25:24:1 ratio) and centrifuged in Phase-Lock tubes at 15,000 RPM at room temperature. Supernatant was transferred to clean tubes. An equal volume of isopropanol was then added to the supernatant and mixed well at room temperature to precipitate the DNA. The DNA was then centrifuged at 10,000g for 10 minutes at room temperature, and then washed in 70% ethanol. After all ethanol was removed, the DNA pellet was eluted in nuclease-free water and incubated at 55C for 1 hour before storing at -20C. Enriched DNA from 5hmC capture were subjected to library construction using the NEBNext Ultra II DNA Library Prep kit for Illumina (New England BioLabs) according to manufacturer's protocol.