Robust hematopoietic specification requires the ubiquitous Sp1 and Sp3 transcription factors [ChIP-seq]

Development requires the cooperation of tissue-specific and ubiquitously expressed transcription factors, such as Sp-family members. However, the molecular details of how ubiquitous factors participate in developmental processes are still unclear. We previously showed that during the differentiation of embryonic stem cells lacking Sp1 DNA binding activity (Sp1deltaDBD/deltaDBD cells), early blood progenitors are formed. However, gene expression during differentiation becomes progressively deregulated and terminal differentiation is severely compromised. Here we studied the cooperation of Sp1 and its closest paralogue Sp3 in hematopoietic development and demonstrate that Sp1 and Sp3 binding sites largely overlap. Sp3 cooperates with Sp1deltaDBD/deltaDBD but is unable to support hematopoiesis in the complete absence of Sp1. Using single cell gene expression analysis, we show that the lack of Sp1 DNA binding leads to a distortion of cell fate decision timing, indicating that stable chromatin bi nding of Sp1 is required to maintain robust differentiation trajectories. Overall design: ChIP-seq in ESC and Flk+