Description
It has been postulated that during human fetal development all cells of the lung epithelium derive from an embryonic endodermal NKX2-1+ precursor, however, this hypothesis has not been formally tested due to an inability to purify or track this theorized cell for detailed characterization. Here we engineer and developmentally differentiate NKX2-1GFP reporter pluripotent stem cells (PSCs) in vitro to generate and isolate a human primordial lung progenitor that expresses NKX2-1 but is initially devoid of markers of differentiated lung lineages. As these progenitors move through the earliest moments of lung lineage specification from definitive endoderm they can be imaged in real time or isolated for time-series global transcriptomic profiling. We performed microarray analysis of 5 timepoints of human iPSC to lung directed differentiation compared to week 21 human fetal lung and Neural NKX2-1+ cell controls. These profiles indicate that evolutionarily conserved, stage-dependent developmental gene signatures are expressed in primordial human lung progenitors.