Fig. 5

Cartilage phenotypes and dlx2 expression in WT and lzr mutants, (from Pöpperl et al., 2000). (A, B) Alcian blue-stained, flat-mounted cartilages of the first and second pharyngeal segments prepared from day 4 embryos. Left side views, dorsal to the top and anterior to the left. In the WT (A) the elements are separated by joints. The abbreviations are as in Fig. 1. In the mutant (B) the dorsal elements as well as the ventral elements in the two segments are fused to one another. DV fusions within each segment occur as well; the DV joints are missing, as is the interhyal cartilage (ih) in the second segment. (C, D) Dorsal views (anterior to the left) of 20-h embryos labeled by RNA in situ hybridization for expression of dlx2. The three separate bilateral patches of expression in the WT (C) correspond to the three streams of postmigratory neural crest that have populated the pharyngeal arch primordia. The streams are fused together in the lzr mutant.