Genome-wide binding analysis of GATA1fl and GATA1s in G1ME cells.. Mus musculus

We used chromatin immunoprecipitation sequencing (ChIP-seq) to compare genome-wide binding profiles of GATA1fl and GATA1s in G1ME cells, which are immortalized, developmentally arrested megakaryocyte-erythroid progenitors (MEPs) derived from in vitro differentiation of murine Gata1- ES cells. Although the truncation in GATA1s leaves the DNA binding domain intact, GATA1s fails to broadly occupy erythroid specific regulatory regions. These observations point to lineage specific co-factor associations essential for normal chromatin occupancy and provide mechanistic insights into how GATA1s mutations cause human disease. Overall design: We performed ChIP-seq on G1ME cells 42 hours after retroviral transfer of HA-tagged full-length GATA1 (GATA1fl) or GATA1s cDNAs (2 replicates each). At this time point, there was no apparent difference in the cell surface phenotypes between GATA1fl and GATA1s-expressing cells. For each ChIP-seq replicate we obtained a matching input sample (non-ChIP DNA) as a control.