Global changes in granulosa cell chromatin accessibility in response to the LH surge and to PGR (ATAC-seq)

During ovulation, the LH surge leads to the activation of various signalling cascades in granulosa cells, resulting in a critical shift in chromatin landscape and correspondingly the ovarian gene expression profile. Such large-scale genomic reprogramming involves a specific suite of ovulatory transcription factors. An essential factor for ovulation is the progesterone receptor (PGR). One of the ways through which PGR can mediate transcription regulation is through interaction with histone and chromatin remodellers to facilitate chromatin reprogramming and thereby enabling transcription. However, it is unknown whether this mechanism is employed by PGR in granulosa cells. This study aims to characterise global changes in the chromatin landscape that are induced by the LH surge and to determine the role of PGR in facilitating chromatin accessibility in granulosa cells during ovulation. ATAC-seq was performed on granulosa cells from wildtype mice pre- and post-hCG stimulation, or from PGR wildtype and knockout mice post-hCG stimulation. 2 biological replicates were done for each condition, 2-3 mice pooled per replicate.