REC8-Cohesin Preferentially Localizes to Promoters of Genes that are Regulated by Transcription Suppressor BEND2 During Early Meiosis.

Cohesin plays critical roles in chromatin organization and transcription regulation. REC8 is a meiosis-specific cohesin subunit and is essential for homologous chromosome synapsis, recombination, and segregation. However, little is known about the relationship between the dynamic genome-wide distribution of cohesin and transcription regulation during meiotic initiation. In this study, we report that REC8-cohesin is preferentially localized to open promoter regions of genes involved in spermatogonial differentiation and meiosis at early meiosis from preleptonema to zygonema. Genomic localization of REC8-cohesin is changed by the gene knockout of the transcriptional suppressor BEND2. We also find that REC8 is able to interact with mitotic cyclin CCNA2, that the CCNA2 expression is extended to leptonema in Bend2 knockout mice, and that the meiotic cells of Bend2 knockout mice do not exit the mitotic cell cycle completely. We further found that a large number of genes are commonly bound by BEND2, STRA8, MEIOSIN, and REC8-cohesin. Our study has therefore revealed that genes with open promoters are bound by meiotic cohesin and transcription factors coordinately to facilitate chromatin reorganization and transcription regulation leading to the switch from a mitotic cell cycle to a meiotic one at the initiation stage of meiosis.