Genome-wide distribution of REC8 cohesin is correlated with active transcription and regulated by transcription suppressor BEND2 during early meiosis [CUT&Tag]

To characterize REC8-binding sites on the genome, we conducted CUT&Tag analyses by using testicular cells of the Rec8-3×FLAG-2×HA knock-in (Rec8 KI) mice whose spermatogenesis was synchronized to preleptotene, leptotene or zygotene spermatocytes. We found that REC8 preferentially binds to open promoter regions of actively transcribed genes. Futhermore, we found the dynamic changes in REC8 binding sites during meiosis are correlated with gene transcriptional status. To describe the changes of REC8 binding sites in Bend2 knockout (Bend2 KO) mice, we conducted CUT&Tag analyses by using zygotene spermatocytes from Bend2 WT and KO mice in Rec8 KI background with HA antibodies. We found both up- and down-regulated REC8 peaks were observed despite of more down-regulated ones. Moreover, we found that these changed peaks were also located in open chromatin regions which was further increased in zygotene spermatocytes of Bend2 KO mice.