The following lentivirus constructs were used: (i) lentivirus vector (FUW-TetO-Ngn2-P2A-puromycin) expressing Ngn2-P2A-puromycin cassette; (ii) lentivirus vector (FUW-TetO-Ngn2-T2A-blasticidin) expressing Ngn2-P2A-puromycin cassette; (iii) lentivirus vector (FUW-TetO-Ascl1-T2A-puromycin) expressing Ascl1-T2A-puromycin cassette; (iv) lentivirus vector (FUW-TetO-Dlx2-IRES-hygromycin) expressing Dlx2-IRES-hygromycin cassette; (v) lentivirus vectors expressing single transcription factors including Myt1L, Lhx1, Lhx6, Dlx5, Pax2 and Nkx2-1 under the control of TetO promoter; and (vi) lentivirus vector (FUW-rtTA) containing rtTA36. For collybistin knockdown (KD) experiments, five shRNA constructs (pLKO.1 backbone) targeting human collybistin isoforms were purchased from Mission Sigma (Sigma-Aldrich). Lentiviruses were produced as described5,10.
