Fig. S1

Fig. S1 olt and ord genes do not affect overall brain patterning. (A-C) tag-1 mRNA expression in the wild-type (A), olt^rw689 (B) and ord^rw71 (C) embryos at 24 hpf. Although the nVII motor neurons showed abnormal behavior and ectopic localization in the olt and ord embryos, they expressed tag-1 mRNA, a marker for nVII motor neurons. All or most of the tag-1-positive cells were located in r4 in the olt and ord embryos (arrows in B and C). Some of the tag-1-positive cells were located in r5 in the ord embryos (arrowheads in C). (D-F) Isl1-GFP expression in the wild-type (D), olt (E) and ord (F) embryos at 5 days post-fertilization. The trajectories of facial motor axons were normal in the mutant embryos (arrows) and the axons reached the target muscles. (D′,E′,F′) Higher magnifications of the boxed regions in D-F. (G-O) Expression pattern of the rhombomere-specific genes in the wild-type (G,J,M), olt (H,K,N) and ord (I,L,O) embryos at 20 hpf. Expression patterns of hoxb1a (G-I), krox20 (J-L) and val/mafB (M-O) mRNA were unaffected in the mutant embryos. (P-R) Commissural axons labeled with zn-5 antibody (red) in the wild-type (P), olt (Q) and ord (R) Isl1-GFP embryos at 36 hpf. (S-U) Reticulospinal neurons retrogradely labeled (red) in the wild-type (S), olt (T) and ord (U) Isl1-GFP embryos at 5 hpf. (S′,T′,U′) Single-channel images for the labeled neurons. Dorsal views of the embryos are shown; the anterior of the embryo is at the top of the figure. Va, anterior trigeminal nuclei; Vp, posterior trigeminal nuclei; VII, facial nucleus; X, vagus nucleus; Allg, anterior lateral line ganglion; Pllg, posterior lateral line ganglion; M, Mauthner′s cell. Asterisks indicate the r6-derived putative octavolateralis efferent (OLe) neurons (Wada et al., 2005). Otic vesicles (ov) are indicated by broken lines. Scale bars: 50 μm.