LAUSR

thoroughly characterize mouse bladder urothelium. METHODS: 18,917 single cells from C57BL/6 mouse bladder urothelium was analyzed by unbiased single-cell RNA sequencing to classify bladder cell types and their underlying functions. RESULTS: Clustering analysis identified 8 distinct cell clusters from mouse bladder urothelial cells. The homology and heterogeneity of mouse bladder urothelial cell types were compared and both conservative and heterogeneous aspects of mouse bladder urothelial cell evolution were identified. Two different types of umbrella cells were distinguished by the marker gene expression of F3, Plk2, Scube2, and Myh14. We also discovered a novel type of bladder urothelial cells marked by Plxna4 that may be involved with collective migration of epithelial cells during the epithelial wound healing. We verify these Plxna4þ epithelial cells also occur in human bladders. We also found a number of bladder pain syndrome-regulating genes differentially expressed among different subtypes. CONCLUSIONS: Our study provides a comprehensive characterization of bladder urothelial cells, which is fundamental to understanding bladder urothelium biology and bladder diseases.