Chromatin remodeling of prostaglandin signaling in smooth muscle enables mouse embryo passage through the female reproductive tract

Early mammalian development occurs during embryo transit of the female reproductive tract. Transport is orchestrated by secreted oviduct fluid, unidirectional beating of epithelial cilia, and smooth muscle contractions. Using gene-edited mice, we document that conditional disruption of a component of the SWI/SNF chromatin remodeling complex in smooth muscle cells prevents transport through the oviduct without perturbing embryogenesis. Analysis with RNA sequencing (RNA-seq), transposase-accessible chromatin with sequencing (ATAC-seq), chromatin immunocleavage sequencing (ChIC-seq), and pharmacologic rescue experiments implicated prostaglandin signaling pathways. In comparison with controls, gene-edited mice had compromised chromatin accessibility at enhancer/promoters of Ptgs2, Pla2g16, Pla2r1, and Ptger3 (EP3) as well as decreased enhancer-promoter interactive looping critical for Ptgs2 (aka Cox-2) expression in a SWI/SNF complex-dependent manner. Treatment of wild-type mice with prostaglandin inhibitors phenocopied the genetically induced defect.