Altered gene expression and chromatin accessibility in R307C GATA1 mutant primary hematopoietic cells. (A) Schematic of experiment. In vitro cultured bone marrow–derived R307C cells and healthy donor cells were sorted using the indicated gate at day 6 of culture for 10× single-cell RNA-seq and single-cell ATAC-seq processing. (B) Uniform manifold approximation and projection (UMAP) depicting myeloid progenitor (MyeP) and early and late erythroid compartments based on single-cell RNA-seq expression data. Healthy donor and R307C cells are jointly embedded, compared with supplemental Figure 6A. (C) Heatmap showing log₂ fold change (FC; R307C/WT) of the expression of select genes as determined by single-cell RNA-seq analysis for indicated genes and cell cluster, compared with panel B. (D) UMAP as in panel B depicting ADA (left) and KIT (right) expression resolved by donor ID. BM, bone marrow; FC, fold change; MNC, mononuclear cell.