Fig. 5. Effects of Fgf8b on down stream gene expression. Fgf8b repressed Otx2 (A-C), induced Gbx2 (D-F), Irx2 (G- I) and Pax2 (J-L) expression. Fgf8b upregulated En2 expression in the diencephalic region (M,N). Whole-mount in situ hybridization for Fgf8b (A,D,G,J, red), and for Otx2 (B,C), Gbx2 (E,F), Irx2 (H,I), Pax2 (K,L) in purple. (M,N) In situ hybridization for Fgf8b (purple) and immunohistochemistry showing En2 expression (brown), C,F,I and L show the control side. An arrow indicates the rostral (M) and caudal (N) limit of En2 expression on the experimental side, and an arrowhead indicates the rostral (M) and caudal (N) limit of En2 expression on the control side. Scale bars, 600 µm.