Fig 1.
Early exposure to mShh-N and 10−8M retinoic acid promotes midbrain regionalization of human ES cell-derived neural progenitor cells. (A) Human ES cells were differentiated by 4 concentrations of RA with mouse Shh for 12 days before exposure to BDNF, ascorbic acid, mouse Shh and Fgf8b for 8 days. (B) Quantitative PCR determined that 10−8M retinoic acid with mouse Shh induced a midbrain-like transcriptional profile by significantly increasing the levels of EN1 without changing the levels of OTX2, HOXB1 and PAX2 (* p < 0.05 ANOVA).