Fig. 2. Abnormal hox gene expression in spg mutants at the 10-somite stage. Dorsal (A-C,G-I,M-W) and lateral (D-F,J-L) views of the hindbrain of wild-type (left column), spg^m216 (middle column) and spg^m793 (right column) embryos at the 10-somite stage. Embryos have been assayed for expression of hox genes (blue) by WISH as indicated at left. krx20 expression (red) in r3 and r5 was also detected. Schematic summary of hox, krx20, ephA4 and val expression in wild-type (X), spg^m216 (Y) and spg^m793 (Z) embryos at the 10-somite stage. The diagrams do not exactly represent the proportional sizes of rhombomeres. The shape of r1 in (Z) is deduced from ephA4 expression at 1 dpf (Fig. 5G,I). In all photographs, anterior is to the left. In D-F,J-L, dorsal is up. 1-7, rhombomeres 1-7.