Fig. 4. Restoring Dlx3b, Dlx4b and Sox9a functions together rescues the Df^b380 mutant ear phenotype at the 10-somite stage. (A,E) Wild-type embryos express pax2a in the presumptive otic placodes. (B,F) Df^b380 mutant embryos lack early otic expression of pax2a (50/51 embryos). (C,G) Injection of wild-type dlx3b mRNA into Df^b380 mutants partially restores otic pax2a expression (13/30 embryos). (D,H) Injection of wild-type dlx3b, dlx4b and sox9a mRNAs into Df^b380 mutants restores otic pax2a expression to nearly normal levels (22/65 embryos). In other experiments, 8/30 Df^b380 embryos injected with dlx3b and dlx4b and 11/33 injected with dlx3b and sox9a showed rescued pax2a expression. (A-D) Dorsal views, anterior towards the left; (E-H) side views, anterior towards the left, dorsal towards the top. Scale bar: 100 µm in A-D; 31 µm in E-H.