Rescue of the midbrain and retinal phenotype in morphants is species-specific. The expression domain of foxb1.2 in un-injected 48 hpf embryos (A) and rho in un-injected 72 hpf embryos (E) is significantly reduced in the MO1a injected embryos (B, F). Co-injection of zebrafish dmbx1a significantly rescues these phenotypes (C, G), whereas co-injection of mouse Dmbx1 mRNA does not (D, H). Arrow in A-D demarcates the region of the rostrolateral hindbrain (where the EG is located) at 48 hpf. For A-D, images represent dorsal views, anterior to the top. For E-H, images represent ventral views, anterior to the top. MO, morpholino; hpf, hours post-fertilization. Asterisk in (C) demonstrates ectopic foxb1.2 expression, which was commonly observed in embryos over-expressed with zebrafish dmbx1a, but not mouse Dmbx1 mRNA.