The CUT& Tag was conducted by using CUT&Tag Assay Kit for Illumina according to the manufacturer's protocol with minor modifications (Vazyme, TD903). Briefly, nuclei were extracted from 5,000 GCs and incubated with ConA beads at least 10 min for comprehensively combination. The complexes were then incubated with primary antibodies overnight, while the IgG antibody were used as negative control. The samples were incubated sequentially with a secondary antibody and a diluted pA-Tn5 transposase was used to cut the genome and add a special adaptor sequence to build a library. All sequencing libraries were established following 12 cycles of PCR amplification. The enrichment of target sites in the library was detected using qRT–PCR. The selected DNA fragments were sequenced on the Novaseq 6000 platform to at least a depth of 2.5×107 reads accordingly.