scRNA-SEQ analysis of Mk-biased CD42⁺ iHPCs. (A) Identification and visualization of transcriptional heterogeneity within sorted L1-C and L1 CD42⁺ iHPCs by dimensionality reduction with UMAP. (B-C) Eight populations were identified in both L1-C (n = 2335) and L1 (n = 2302) cells by grouping of cells based on DE genes and gene ontology analyses, using lists of genes from select clusters with the highest detected number of DE genes to show functional enrichment in control CD42a⁺ iHPC clusters only (B) or processes (C) that are upregulated in L1 vs L1-C CD42⁺ iHPCs. (D-E) Volcano plots showing significantly changed genes among all DE genes (D) or focusing on Mk/platelet (Plt)-associated genes (E), when L1-C to L1 CD42a⁺ iHPCs were compared across all clusters. To improve clarity, only select genes are shown and labeled. (See supplemental Tables 5 and 6 for a full list.) Filled red circles denote significantly changed genes; unfilled red circles indicate DE genes that are not Mk/platelet associated.