Single cell map of the adult female mouse urethra reveals epithelial and stromal macrophages with distinct functional identities

We have employed single cell RNA-sequencing to create a cellular atlas of the female mouse urethra. The epithelial lining of the urethra is an understudied mucosal barrier. Emerging evidence points to the role of the urethra in pathogen surveillance, sensation and response. To investigate the heterogeneity of the resident immune niche in the adult female mouse urethra, we performed single cell RNA-sequencing which revealed the presence of distinct epithelial-associated and stromal macrophages in the urethra. Overall design: Wildtype CD-1 adult female mouse urethras were digested to single cells for sc-RNA seq using the 10x Genomics platform. To assess immune cell distribution in the epithelial and stromal compartments, adult female mouse urethras were enzymatically digested and the epithelial and stromal compartments were separated mechanically. Resultant tissue was digested into single cells and subjected to single cell RNA-sequencing to obtain cell types enriched in the epithelial and stromal compartments of the urethra.