Single-cell RNA-seq reveals the diversity of trophoblast subtypes and patterns of differentiation in the human placenta

In this study, we isolated human villous stromal cells (STRs), CTBs, the STB, and EVTs at the first and second trimester of pregnancy and monitored the transcriptome dynamics of 1567 cells at single-cell resolution. We identified 14 subtypes of placental cells and characterized their functions, especially the unexpected secretion of 102 polypeptide hormone using bioinformatics analyses and immnunostaining verifications. Our study builds a strong foundation for understanding how the human placenta develops and functions to maintain a healthy pregnancy.