Single-cell suspensions were prepared from pancreata of Neurogenin 3-eGFP mouse embryos sacrificed at different days of embryonic development. Single eGFP-positive cells were FACS-sorted into 96-well plates, and single-cell cDNA was prepared using the SMART-seq protocol. Single-cell sequencing libraries were generated using the Nextera XT DNA library preparation kit and sequenced on an Illumina HiSeq sequencer. Reads were aligned to the mouse reference genome build mm10 with TopHat, and single-cell gene expression profiles were computed using Cufflinks.