Transcription factor NFYA directs male meiotic entry by facilitating accessible chromatin at the promoters of genes expressed during meiosis [scRNA-seq & scATAC-seq]

Meiotic prophase I characterized by homologous recombination and synapsis is an intricate step for spermatogenesis. This process entails extensive changes to chromatin and transcription. Recent studies have revealed that prior to prophase I, accessible chromatin bound by paused Pol II at meiotic gene promoters is essential for their timely activation during later stages of prophase I. However, the factor responsible for promoting accessible chromatin at meiotic gene promoters before entry into prophase I is unknown. Here, we discovered that NFYA expressed in pre-meiotic germ cells promotes accessible chromatin at meiotic gene promoters. Concordantly, conditional germline deletion of Nfya in male mice blocks meiotic entry. Functionally, our spatial and single-cell ATAC-seq data revealed that loss of NFYA in pre-meiotic cells disrupts accessible chromatin at meiotic gene promoters. Our study identifies a pioneer role for NFYA in facilitating permissive chromatin at meiotic gene promoters before meiosis, thereby controlling the timely activation of meiotic genetic program during later meiosis. We performed single-cell RNA sequencing (scRNA-seq) and single-cell ATAC sequencing (scATAC-seq) on adult Testis tissue to simultaneously profile the whole transcriptome and assess genome-wide chromatin accessibility at single-cell resolution.