The transcriptional landscape is altered in W⁴¹/W⁴¹mice and lacks cells entering a mast cell differentiation program. (A) Cluster identity of WT LK cells. Cells were clustered into 13 clusters using Louvain clustering on the k-nearest-neighbor graph connected scRNA-seq profiles. Cluster identifiers are ordered by size, with cluster 1 containing the most cells and cluster 13 the least. (B) W⁴¹/W⁴¹ LK cells from 2 animals were sequenced and then assigned to WT clusters based on the cluster identities of their nearest WT neighbors. The color in the plot indicates which WT cluster the W⁴¹/W⁴¹ cell was mapped to. (C) The 15 nearest neighbors of W⁴¹/W⁴¹ LK cells from cluster 9 were identified in the WT LK data. Nearest neighbor score represents the number of times a WT is one of those nearest neighbors. (D) Sorting strategy used to isolate BMCPs from bone marrow of W⁴¹/W⁴¹ mice. The frequency of BMCPs is indicated as percentage of Lin⁻Sca-1⁻c-Kit⁺ cells. (E) BMCPs, MPs, and GMPs were cultured in 86 to 100 cell bulk pools for 5 days with myeloid-promoting cytokines and analyzed by flow cytometry. (F) Colonies derived from single BMCPs and MPs cultured in myeloid-promoting conditions were analyzed with flow cytometry. The number of single-cell colonies in which the cell types were determined is indicated above each bar. Supplemental Figure 8C shows the colony sizes. Single GMP colonies were not analyzed. The gating strategy is shown in supplemental Figure 4B,E. The data are pooled from 2 independent experiments. Pooled bone marrow cells from 2 or 3 mice were used in each experiment.