Fig. 7. Shh and Bmp7 direct mouse ES cell-derived neural progenitor cells to an Nkx2.1+/Th+ DA fate. (A-E) Mouse ES cell-derived neural progenitor cells, cultured without (A-C) or with (D,E) Shh and Bmp7. In control cultures, Th+, Six3+, Nkx2.1+ and Shh+ (A-C) cells are observed but no Nkx2.1+/Th+ neurons are detected. In the presence of Shh and Bmp7, many Nkx2.1+/Th+ cells (arrows in E) are found (D,E). (F) Quantification of Nkx2.1+/Th+ neurons after directed ES cell differentiation. The average number of Nkx2.1+/Th+ cells in cultures shows a significant increase after exposure to Shh and Bmp7 (control 0.66±0.42 cells/2.56mm²; +Shh+Bmp7 51.44±7.27 cells/2.56mm², P<0.0001; unpaired t-test), whereas the average of total number of Th+ cells does not show any significant difference (P>0.05, unpaired t-test; data not shown). Scale bar: 150 µm in A,D; 40 µm in B,C,E.