GATA3 is redundant for maintenance and self-renewal of hematopoietic stem cells

Abstract GATA3 has been identified as a master regulator of T helper cells, as well as being important for early thymic progenitors and T-cell commitment. However, Gata3 expression initiates already at the hematopoietic stem cell (HSC) level, implicating a potential role also in the regulation of HSCs. Herein we used a conditional Gata3 knockout strategy in which Gata3 expression was completely deleted from the earliest stage of embryonic hematopoietic development after emergence of HSCs from hemogenic endothelium. Through a detailed analysis of HSCs at the phenotypic and functional level, we demonstrate that steady-state levels of HSCs are normal in Gata3fl/flVav-Cretg/+ mice. Moreover, through long-term primary and secondary transplantation experiments, we also unequivocally demonstrate that Gata3 has a redundant role in post-transplantation HSC self-renewal.