keratin, and cell-cycle genes such as Ccna2, Ccnb2, Nuf2, and Anln were dramatically downregulated (Figure S2; Table S4). Neighboring time points clustered together, indicating a gradual process of cell type conversion. Gene ontology (GO) term analysis of the 200 most strongly increased genes revealed highly significant enrichment of interacting factors that control neuron generation and function (Figures 3F and S2; Table S5). As expected, FACS-puri fied neurons showed marked enrichment of neuronal genes such as neuronal Ca2+ and K+ channels, glutamate receptors, synaptic proteins, and neuronal cytoskeletal markers as compared to their unsorted counterparts (Figures 3E and 3G), indicating efficient purification of iNs from remaining fibroblasts for RNA-seq.
