design: the experiment type of library construction was in situ Hi-C, including crosslinking DNA, cutting with restriction enzyme Hind , filling ends and marking with biotin, ligating, purifying, and shearing DNA into 300bp~700bp fragments and pulling down biotin. The concentration and insert size of the library were detected by Qubit2.0 and Agilent 2100, respectively. Next, the library was sequenced by using the Illumina NOvaSeq 6000 platform (PE150)