Altered fidelity of GATA1 mutant chromatin occupancy in primary hematopoietic and G1E cells. (A) Schematic of experiment. In vitro cultured bone marrow (BM)–derived R307C cells and healthy donor cells were sorted using indicated gates at day 6 and day 12 of culture for GATA1 CUT&RUN. (B) Volcano plot showing differential GATA1 chromatin occupancy peaks in R307C and healthy donor cells (combined day 6 and day 12). (C-D) GATA1 chromatin occupancy at indicated loci in R307C and healthy donor cells at indicated time points, showing predominantly reduced (C) or increased (D) chromatin occupancy of the R307C mutant. Arrows highlight selected sites of differential chromatin occupancy. (E) Schematic of experiment. G1E cells transduced with indicated hemagglutinin (HA)-tagged GATA1 expression constructs were processed for ChIP-seq. (F) Volcano plot showing differential GATA1 chromatin occupancy peaks comparing G1E cells expressing R307C/H mutants and GATA1 WT. (G) Density plot showing correlation of chromatin occupancy fold changes between G1E cells expressing R307C or R307H mutant and GATA1 WT. (H) Correlation of chromatin occupancy and gene expression fold changes between G1E cells expressing R307C/H mutant and GATA1 WT. MNC, mononuclear cell.