Fig. 6. Hh and Nodal signals have both discrete and cooperative roles in hypothalamus formation. In all panels, genotype + injected RNA/drug treatment is shown in the top right-hand corner, genes/proteins visualized are indicated in the bottom right-hand corner. (A-D) Lateral views of 28 hpf brains. (E-F) Dorsal views of shield stage MZoep embryos showing induction of shh expression upon tar* RNA injection. (G-L) Sections through the hypothalami of wild-type embryos in which ß-gal-labeled cells (brown) were transplanted into the prospective hypothalamus at shield stage. (G-J) Sections through 28 hpf brains. The arrowheads in H,J indicate cells that have been expelled to the mesenchyme around the eyes. This was never observed for MZoep cells or cells expressing Fast1SID and thus does not depend on the depth at which cells were transplanted into the epiblast. (K,L) Sections through bud stage neural plates. Cells were found at various positions along the anteroposterior axis within the nk2.1a expression domain. dd, dorsal diencephalon; h, hypothalamus; t, telencephalon. Scale bars: 25 µm.
