Figure 2.

Generation of GTEV/IGTE ES cells accurately regulating expression of the hAP reporter gene. (A) Structure of the bicistronic gene-trap expression vector pIGTE2-hAP. SA, adenovirus major late-transcription splice acceptor; hygro^r-EGFP, fusion gene encoding resistance to hygromycine B and expression of EGFP; hAP, gene encoding hAP; IRES, internal ribosomal entry site of the Moloney murine leukemia virus; STOP, transcription termination from simian virus 40; STOP, transcription termination from the mouse pgk-1 gene. (B–E) Histochemical analysis of hAP activity in undifferentiated ES cells (B and C) and 8-day-old embryoid bodies (D and E) cultured with 4′OHT (1 μM, 48 h; C and E) or with vehicle alone (B and D). (Scale bars = 100 μM.)