ATAC-Seq of foetal blood progenitors

Chromatin accessibility was assessed by ATAC-Seq in lymphoid-primed multipotent progenitors (LMPPs) from human foetal livers (FLs) and mouse wild-type FLs as well as FLs from mouse embryos that express the oncofusion Mll-AF4 in the definitive blood system. The aim of this study was to establish whether overall chromatin accessibility at key haematopoietic sites and loci that have been linked to leukaemia are differentially accessible in human vs mouse LMPPs and whether this is altered by the expression of the Mll-AF4 oncofusion. 1000-5000 LMPPs (Lineage- CD34+ CD38- CD19- CD45RA+) from human FLs (10-20 weeks of gestation) and 5000-15000 LMPPs (Lin- CD45+ ckit+ Sca1+ Flt3+) from wild-type and Mll-AF4-expressing E14.5 FLs were isolated. Cells were sorted straight into transposition buffer, followed by tagmentation, PCR amplification and library clean up