scRNA-seq of kidney marrow cells from Gata2b deficient and wild type zebrafish

GATA2 is a pivotal hematopoietic transcription factor required for generation and maintenance of hematopoietic stem cells (HSCs). Due to early embryonic lethality of Gata2 deficiency in mice, its role during adult hematopoiesis is incompletely understood. In zebrafish, mammalian functions of Gata2 are split between two orthologues: Gata2a and Gata2b. Previous studies have shown that Gata2b is prominently expressed in hematopoietic stem and progenitor cells (HSPCs), whereas Gata2a is mainly expressed in the vasculature. We found that Gata2b deficient zebrafish have a reduction in embryonic definitive HSPC numbers and have impaired myeloid lineage differentiation, but are viable. This allowed us to study the role of Gata2b in adult hematopoiesis. To assess the impact of Gata2b deficiency on the transcriptional profile of HSPCs and differentiated cells, we sorted the entire progenitor and HSPC population including the lymphoid population from kidney marrow (KM) of WT and germline Gata2b deficient zebrafish based on scatter profiles and processed for single-cell RNA sequencing. To enrich the scarce HSC population, we used pooled KM from two WT and Gata2b deficient Tg(CD41:GFP) zebrafish per sample and included all CD41:GFPlow expressing cells present in the kidney marrow pool as these cells were shown to contain transplantable HSCs.