Active maintenance of accessible chromatin at poised meiotic promoters by the NFYA-NURF axis is required for meiotic entry in mice

Developmental genes often acquire accessible chromatin prior to their activation, yet the mechanisms regulating this permissive state remain poorly understood. During spermatogenesis, many meiotic gene promoters display this poised state in spermatogonia, characterized by accessible promoters and paused RNA Pol II occupancy before their activation during meiosis. Here, we identify the NURF chromatin remodeling complex, comprised of SMARCA5 and its accessory subunit BPTF, as a key regulator of this process. We demonstrate that the transcription factor NFYA interacts with SMARCA5 and is required for its occupancy at poised meiotic gene promoters. Approximately one-third of poised meiotic gene promoters is co-occupied by NFYA, SMARCA5, and BPTF. Germline deletion of Smarca5 disrupts chromatin accessibility at poised meiotic promoters, impairs transcriptional program required for mitosis-to-meiosis transition, resulting in developmental arrest at meiotic entry. These findings identify NFYA-NURF as a key regulatory axis that regulates accessible chromatin at developmentally poised meiotic genes and primes them for activation later during meiosis.