Embryonic erythropoiesis and hemoglobin switching require transcriptional repressor ETO2 to modulate chromatin accessibility and looping (ChIP-Seq)

To determine direct targets and the regulatory role of ETO2 in gene expression, we performed ChIPmentation with antibodies to unmodified ETO2 and ETO2 interacted factor LDB1. A de novo MEME search performed on ETO2-occupied sites, revealed enrichment for GATA and TAL binding motifs, which are the components in LDB1 complex. Nearly 86% of ETO2-binding sites were intergenic or intronic, suggesting ETO2 functions primarily in regions of the genome likely to encompass enhancers. Notabley, ETO2 occupancy was almost completely coincident with LDB1 (97% of 7,761 sites), consistent with the presence of ETO2 exclusively within the LDB1 complex and their co-function in gene regulation. ChIPmentation was performed using antibodies of ETO2 and LDB1 to identify global occupancy of these two factors.