Figure 1.

Spry1-2 loss of function upregulates Fgf-regulated genes in the E12.5 RPC and dorsal telencephalon. A–D′, RNA in situ hybridization for Etv5 (A, A′), Etv4 (B, B′), Sp8 (C, C′), and Mest (D, D′) showing the upregulation of Fgf-regulated genes in the medial/dorsal pallium (arrowheads in A′, B′, C′, D′). E, E′, Coup-TFI, a gene with a complementary expression pattern to Spry1-2, and repressed by Fgf signaling, is downregulated. F, F′, Fgfr3 expression, similar to Coup-TFI, and repressed by Fgf signaling, is shifted ventrally (F′ arrowhead). G, G′, Axin2 RNA expression can be used as WNT signaling readout: in Spry1-2^−/− its reduced expression suggests that Fgf signaling represses WNT signaling. H, I, Spry1 (β-galactosidase staining) and Spry2 expression in WT sections. DP, dorsal pallium; VP, ventral pallium; MP, medial pallium; SP, septum; LGE, lateral ganglionic eminence. Scale bar, 200 μm.