E11.5 Osr1 GCE/+ cells
E11.5 embryo trunks (n = 6) were dissociated and Osr1-GFP+ cells were FACS-sorted. The single-cell suspension was processed using the SMARTer iCell8 system. High-quality single-cells were selected (1609 wells), and SMART-Seq libraries were prepared following the manufacturer's protocol. Final libraries were purified, validated, and sequenced on a HiSeq-4000 (2 x 75 paired-end configuration)