Fig. 5

Whole mount in situ hybridization of 24 hpf (A–C) and 48 hpf (D–F) zebrafish embryos using probes specific for hoxb3a transcript I (exon 4; column 2), transcript II/III (exons 1–3; column 3), and exon 6 that is included in all hoxb3a transcripts (column 1). Transcript I is expressed in r5 and r6 (B and E), whereas transcript II/III is expressed in r7 and r8 (C and F) and posterior. All three transcripts resemble the known expression pattern of zebrafish hoxb3a (A and D; Prince et al. 1998). In panels G to R, vibratome sections (30 μm) from anterior to posterior through the hindbrain of hybridized 48 hpf embryos are shown. (G, J, M, and P) Embryos were hybridized with an exon 6 probe; (H, K, N, and Q) embryos were hybridized with an exon 4 probe; (I, L, O, and R) embryos were hybridized with an exons 1–3 probe. The levels of sections (r5, r6, r7/r8, and spinal cord) are indicated left of each row. Abbreviations: r, rhombomere; sc, spinal cord; ov, otic vesicle. Arrows point to hindbrain expression domains.