The spatial pattern of gli2b expression during zebrafish embryogenesis. Whole-mount in situ hybridization was performed as described in the Experimental Procedures section. The stages and views of embryos as well as probes used for in situ hybridization are indicated in each panel. A: A 3 hours postfertilization(hpf) embryo. Note that gli2b mRNA is present mainly in nuclei. B: A 6 hpf embryo. gli2b transcripts are found in the cytoplasm. C,E: Flat mount of three-somite stage embryos hybridized with the gli2b (C) and gli2 (E) probes, respectively. D: Dorsal view of the anterior portion of an 18 hpf embryo hybridized with the gli2b probe. F,G: Lateral (F) and dorsal (G) views of 24 hpf embryos hybridized with the gli2b probe. H: Cross-section of the 24 hpf embryo in G at the otic vesicle level (dash line in G). I,J: Expression of gli2 provided for comparison with F, G. K: A 24 hpf mib^-/- embryo hybridized with the gli2b probe. L,M: Expression of gli2b (L) and gli2 (M) mRNA in the ventral diencephalon of 48 hpf embryos. N: Expression of gli2b mRNAs in the ventral diencephalon of 48 hpf mib^-/- embryo. L-N: Anterior (A) / posterior (P) axis and adenohypophysis (broken line) of embryo are indicated. ahp, adenohypophysis; di, diencephalon; FMB, forebrain-midbrain boundary; hb, hindbrain; hp, hypothalamus; mb, midbrain; MHB, midbrain-hindbrain boundary; ot, optic tectum; ov, otic vesicle; pt, posterior thalamus; te, telencephalon.

Analysis of gli2b expression in the hindbrain. A-D: Dorsal view of the temporal change of gli2b expression pattern in rhombomeres 4-6 in the hindbrain region at 32-48 hours postfertilization (hpf). E,F: Lateral view of 48 hpf embryos hybridized with the gli2b (E) and gli2 (F) probes, respectively. G: Cross-section of the 48 hpf embryo at the level indicated by the dash line in E. gli2b mRNA is detected in two clusters in the medial part of the neural tube (arrows) and bilaterally immediately above the otic vesicle (arrowheads). H: Two-color staining of a 48 hpf embryo by using gli2b riboprobe and zrf-1 antibody to demonstrate close association of gli2b-positive domains with the endfeet of radial glia distributed in a checkered manner. I: Enlargement of the region boxed in H. J: Montage of gli2b expression shown in H,I. Expression domain of gli2b was redrawn in blue for clarity. The lateral clusters of gli2b-positive cells projected in between curtains of the radial glia clusters. K-M: gli2b expression in the hindbrain in selected mutant embryos: syu^-/- (K), smu^-/- (L), and mib^-/- (M). N: gli2b expression in a shh mRNA-injected embryos (48 hpf). ov, otic vesicle; r4-r6. rhombomere4-6.