Epigenetic profiling of cycling endometrium at single-cell resolution

The human menstrual cycle can be divided into two major phases by the event of ovulation. Before ovulation, in the proliferative or follicular phase, the endometrium proliferates under the influence of estradiol produced by growing ovarian follicles. After ovulation, in the secretory or luteal phase, ovarian progesterone produced by the newly formed corpus luteum drives a process of differentiation during which the endometrium becomes competent to receive and support the growth of the embryo. Single-cell analyses at the RNA level from our group and others have begun to decipher cell-type specific expression in the endometrium. How these events are controlled at the chromatin level remains elusive, however. In this study, we applied single-cell assay for transposase-accessible chromatin using sequencing (scATAC-seq) to profile the epigenetic landscapes of human endometrial samples across the menstrual cycle. Overall design: Twelve timed endometrial biopsies were processed as described in detail elsewhere (Brighton et al., 2017) and subjected to single-cell ATAC-seq.