Distinct HSPC composition in BM, spleen (SPL), and PB. (A-E) Analysis of 10X scRNA-seq data from 117 200 cells, combining all donors but comparing different tissues (BM, 34 967 cells; SPL, 22 068 cells; PB, 60 165 cells). (A) Two-dimensional kernel density of cells across the Uniform Manifold Approximation and Projection (UMAP) coordinates of each tissue, displayed as contours filled by a color gradient. (B) Bar graph of the relative composition of HSPC groups in BM, SPL, and PB. Each group was defined as shown in Figure 1. Mean ± standard deviation is shown. (C) Relative number of megakaryocyte progenitors (MkPs) (cluster 22) in each tissue. (D) The ratio of early to late progenitors of the MEMB (left) or My (right) branch is shown. Kruskal-Wallis; Dunn’s multiple comparison test. (E) Three-dimensional plots show lineage scores as in Figure 1B for each tissue. (F) Force Directed Graph computed by using CITE-seq protein data of 2 BM (OD3, 9 477 cells; OD4, 12 500 cells) and 1 SPL (OD4, 11 822 cells). Left, Leiden clusters as annotated based on known surface marker expression (supplemental Figure 2D). Right: density visualization of the distinct cell distributions for each tissue in different areas of the landscape. For panels B and C, 1-way analysis of variance with post hoc Tukey test, except for LyP and EryP/MyPmix clusters (not normally distributed, italic text), for which a Kruskal-Wallis test with Dunn’s multiple comparison was used. Data in panels C and D are given as median ± 95% confidence interval. OD, organ donors; LD, living donor; ns, not significant (P > .05).