Fig 1: Mrgprb2+ and Mrgprb2neg MCs represent transcriptionally distinct MC populations. (A) UMAP plot of the scRNAseq performed on sorted peritoneal cavity. MCs. (B) UMAP plot of the scRNAseq performed on sorted immune cells from the back skin. Black arrowhead: MC population. (C). UMAP plot of the scRNAseq performed on sorted immune cells from the gut mucosa. Black arrowhead: MC population. (D) Violin plot of the expression of Mrgprb2, Mrgprb1, Mcpt4, Mcpt1, Kit, and Cpa3. (E) UMAP plot of all MC populations aggregated. (F) PCA showing the segregation between skin/peritoneal cavity and gut MCs. (G) Heatmap of 74 representative DEGs between MCs from gut, peritoneal cavity, and skin MC related. Characteristic genes and surface markers upregulated in gut (green) or peritoneal cavity and skin MCs (red) are highlighted. (H and I) (H) Mrgprb2 and (I) Mcpt1 expression density on the aggregated populations. (J) Representative 3D confocal microscopy images of Avidin SRho (red), Mcpt1 (green), and DAPI (cyan) fluorescent signals of back skin, duodenum, and colon. Arrows indicate gut mucosa and muscularis. Data are representative of three independent experiments. Bars = 100 (skin) and 70 (duodenum and colon) μm. DC, dendritic cell; NK, natural killer.