Fig. 3. In situ hybridisation analysis of Wnt gene expression in the forebrains of E10.5 embryos lacking Gli3 function. (A,B) Wnt3a expression in wild-type embryos covers the dorsomedial telencephalon, while Xt^J/Xt^J embryos completely lack Wnt3a mRNA in this tissue. (C,D) Wnt8b expression in homozygous Xt^J embryos is disrupted, except for a narrow band of cells in the caudal telencephalon (arrowhead) (E) Wnt7b is expressed in the dorsal telencephalon of wild-type embryos with highest expression levels in the dorsomedial part (arrows). (F) Wnt3a mRNA is specifically absent from the dorsomedial telencephalon of Xt^J/Xt^J embryos (arrow), but still present in the dorsolateral telencephalic neuroepithelium.