Fig. 1. Expression patterns of HD proteins and Shh in the tuberal hypothalamus. Whole-mount lateral views (A,B) or transverse sections through the tuberal hypothalamus (C-Q) of stage 10-15 embryos. (A,B) Double-label immunofluoresence to detect Shh (green) and Nkx2.1 (red) at stage15. In the diencephalon, Nkx2.1+/Shh+ progenitor cells occupy the anterior ventral hypothalamus (asterisk) and lateral tuberal hypothalamus (arrow) (see R). These populations have previously been defined as `anterior-dorsal' hypothalamic cells (Mathieu et al., 2002). Blue shows DAPI counterstain. Telencephalic cells express only Nkx2.1 at this stage. (C-E,G-I) Double-label immunofluorescence reveals expression of Nkx2.1 and Shh at stage 10 (C), stage 13 (D) and stage 15 (E,G-I). From stage 15, Shh and Nkx2.1 are co-expressed by cells in the germinal zone I (G-I). (F) Shh mRNA expression in the germinal zone. (J-M) Double-label immunofluoresence shows expression of Lim1 and Nkx2.1. Lim1 is strongly expressed in lateral hypothalamic cells and overlaps extensively with Nkx2.1. (N,O) Nkx2.2 overlaps with Nkx2.1 and then extends more dorsally. (P,Q) Nkx2.2 expression is complementary to Pax6 expression. (R,S) Summary diagrams showing hypothalamic nomenclature, HD protein codes and Shh expression. Lim1^* denotes high expression in lateral tuberal hypothalamic cells. For simplicity, weak Lim1 expression in more dorsal region is not shown in this diagram. AH, anterior hypothalamus; TuH, tuberal hypothalamus; MH, mammilary hypothalamus. Scale bars: 300 µm in A; 130 µm in B; 65 µm in C-F,J,N,P; 30 µm in G-I,O,Q; 25 µm in K-M.