DNA methylation of mouse sperm
library preparation began with the digestion of 100200 ng genomic DNA using 4 U FspEI at 37 C for 4 h. Then, a ligation master mix containing library-specific adaptors, ATP and T4 DNA ligase was added to the digestion product and incubated at 4 C for 16 h. In the second PCR amplification, specific adapter-barcode was incorporated into each library, and then all libraries were pooled for single-end sequencing (1  50 bp) using an Illumina HiSeq 2000 sequencer.