Fig. 8. Expression patterns of Fgf3 and kreisler/Mafb in Gbx2^-/- embryos. Lateral (A,B) and dorsal (C,D) views of the kreisler/Mafb expression pattern in the hindbrain of Gbx2^+/– (A,C) and –/– (B,D) embryos. (A,B) No obvious difference in kreisler/Mafb expression pattern is observed between +/– and –/– embryos before 9.0 dpc. (C,D) By 9.5 dpc, kreisler/Mafb is expressed weakly in r6 of +/– (C, arrowhead) and much more strongly in –/– (D) embryos. (E,F) Dorsal and (G,H) lateral views of the Fgf3 expression patterns in the hindbrains of heterozygous (E,G) and homozygous (F,H) Gbx2 mutants. (E,F) At 9.0 dpc, the Fgf3 expression domain extends beyond r5 and r6 into r4 and possibly includes the undefined region rostral to r4 in Gbx2^-/- embryos. (G,H) By 9.5 dpc, Fgf3 expression is no longer detectable in the hindbrain (G) but is strong in r4 and rX (asterisk) and weaker in r6 (arrowhead) of Gbx2^-/- embryos (H). The Fgf3 expression patterns in both otocysts (G,H) are comparable in the anteroventral lateral region. Arrows in C-H mark the anterior and posterior margin of the otocyst. sm, somite pairs. Scale bars: in A, 100 µm for A,B; in C, 100 µm for C,D; in E, 100 µm for E-H.