Fig. 5. Misexpression of Irx3 resulted in an ectopic tectum formation in the forebrain. (A) Dorsal view of a dissected brain of a HH39 embryo that had been electroporated with Irx3 in the forebrain region at HH11. A small bulge is visible on the right side (electroporated) of the diencephalic region (arrow in A). (B) Thionine staining and (C-E) immunostaining for Pax7 of coronal sections of the ectopic bulge (B-D) and the normal tectum (E). (D,E) High-power views of the sections, in which the ventricle is located at the bottom of the panels. The ectopic bulges exhibit layered organization (arrow in B), and expression of Pax7 in both the ventricular zone (arrow in C,D) and some upper layers of cells (bracket in D), which resembles the optic tectum (arrow and bracket in E). Bars, 0.5 mm. ce, cerebellum; my, myelencephalon; ot, optic tectum; te, telencephalon.