Cross-species insights into placental evolution and diseases at the single-cell resolution

Abstract The placenta is essential for fetal development, yet its molecular evolution across mammals remains elusive. Here, we present a comprehensive single-cell transcriptomic atlas of ~300,000 cells from ten species representing the four primary placental types: discoid, cotyledonary, diffuse, and zonary. Our cross-species analysis identifies trophoblast lineages as the primary drivers of placental diversification. By reconstructing differentiation trajectories, we elucidate the regulatory ne