Gata2 loss alters epigenetic priming and gene expression profiles in early myeloid and lymphoid progenitors leading to cytopenias [RNA-seq]

Germline heterozygous mutations in GATA2 are associated with a syndrome characterized by cytopenias, atypical infections, and increased risk of hematologic malignancies. Due to embryonic lethality of Gata2-/- mice, the role of germline loss of GATA2 has not been studied in adult hematopoiesis. Here, we generated a zebrafish mutant of gata2b, which in adulthood recapitulated the myelomonocytopenia and B cell lymphopenia of GATA2 syndrome. Using single cell epigenetic and transcriptomic analyses, we showed that loss of gata2b alters chromosome accessibility and results in gene expression changes in both early myeloid and lymphoid progenitors. We found differentiation block with skewing away from the monocytic program in myeloid progenitors in gata2bko zebrafish. In lymphoid progenitors, gata2b loss led to increased lymphoid priming but with incomplete B cell lymphopoiesis. These results place GATA2 in critical junctions of lineage specification in adult hematopoiesis. Overall design: Single cell RNA sequencing were performed on sorted zebrafish kidney marrow cell from wildtype, gata2b heterozygous and gata2b homozygous mutants (exon 2 CRISPR mutants described in this paper), n=3 each genotype. The zebrafish underwent cardiac bleeding to reduce amount of peripheral blood in the marrow samples. Cells were sorted on BDAria2 sorter into 1x PBS with 0.04% BSA. The goal of sorting was to enrich for no mature myeloid and erythroid cell types, comprising <50% of the adult marrow cells.