Stromal cells-specific retinoic acid determines parturition timing at single-cell and spatial-temporal resolution.

The underlying mechanisms governing parturition remain largely elusive due to limited knowledge of parturition preparation and initiation. Accumulated evidences indicate that maternal decidua plays a critical role in parturition initiation. To comprehensively decrypt the cell heterogeneity in decidua approaching parturition, we investigate the roles of various cell types in mouse decidua process and reveal previously unappreciated insights in parturition initiation utilizing single-cell RNA sequencing (scRNA-seq). We enumerate the cell types in decidua and identity five different stromal cells populations and one decidualized stromal cells. Furthermore, our study unravels that stromal cells prepare for parturition by regulating local retinol acid (RA) synthesis. RA supplement decreases expression of extracellular matrix-related genes and accelerates the timing of parturition . Collectively, the discovery of contribution of stromal cells in parturition expands current knowledge about parturition and opens up avenues for the intervention of preterm birth (PTB).