ChIP was performed as previously described (Lee et al., 2006) by using FLAG antibody (Sigma, F1804) based IP in T10F10 ESCs. 20 µl of 435 ng/µl input and 33.8 ng/µl FLAG-ChIPed DNA were prepared for input and Tex10 ChIP-seq libraries. Massively parallel sequencing was performed with the Illumina HiSeq 2500 according to the manufactory protocol. All libraries were sequenced as 100 bp single-end reads.