Fig. 4. Expression of Dlx genes in p63 mutant limbs. (A,A') Lateral view of p63^+/EEC (A) and p63^EEC/EEC (A') E11 embryos. Note the dysmorphology of both FLs and HLs in the homozygous embryo (black arrows). (B-E) Immunostaining for E-cadherin on sections of p63^+/EEC (B,D) and p63^EEC/EEC (C,E) E10.5 FL (B,C) and HL (D,E), to examine stratification of the AER (white arrows). Section plane as in Fig. 1. Scale bar: 25 µm. White arrows indicate the dorsal and ventral border of the AER. (F-K) Whole-mount in situ hybridization for Dlx5 on p63^+/EEC (F,H,J) and p63^EEC/EEC (G,I,K) E10 embryos, showing the pharyngeal arches (F,G), the FLs (H,I) and the HLs (J,K). Signal is reduced in the AER of p63^EEC/EEC limbs (black arrows in H-K), but not in the p63^EEC/EEC pharyngeal arches (white arrows in F,G). (L-O) Whole-mount in situ hybridization for Dlx5 on FLs (L,M) and HLs (N,O) of E9.5 p63^+/- (L,N) and p63^-/- (M,O) embryos, in lateral view. The signal on the pre-AER is indicated (black arrows). Anterior is to the right. (P-W) In situ hybridization for Dlx2 (P-S) and Dlx5 (T-W) on sections of WT, p63^+/EEC; p63^EEC/EEC and p63^-/- E10.5 HLs. The AER is indicated with black arrows. Asterisks indicate absence of hybridization signal. (X-Z) Immunostaining for pan-Dlx on sections of wild-type, p63^EEC/EEC and p63^-/- E10.5 HLs.