Fig. 6. Effects of Sprouty2 misexpression on Otx2, Gbx2 and Fgf8 expression. In situ hybridization for Otx2 (A-D, purple), Gbx2 (E-H, purple) and Fgf8 (I-K, purple). Misexpression of Sprouty2 is assessed by immunohistochemistry with the antibody against HA-tag (A,E,I, brown); 24 hours after electroporation (HH 18; A-C,E-G,I-K); 48 hours after electroporation (HH 22; D,H). Sprouty2 induced Otx2 expression, and repressed Gbx2 expression in the metencephalic region. (D,H) By 48 hours after electroporation, regulation of Otx2 and Gbx2 expression may have occurred and the expression domain of these genes reduced. (J) The Fgf8 expression ring shifted caudally. mes, mesencephalon; is, isthmus; cont, control side; exp, experimental side. Scale bar: 200 µm.