Fig. 2. Early expression of foxi one in the developing embryo. (A,B) Antisense RNA in situ hybridization of foo mRNA is first detected in the dome stage of embryos. (A) Lateral view; (B) dorsal view. (C) Lateral view of foo expression at the shield stage. (D) Lateral view 90% epiboly. Arrow indicates foo expression in the otic placode precursors. (E) Lateral view of a foo^hi3239/foo^hi3239 embryo, 90% epiboly. Arrow indicates loss of foo expression in the mutant embryo. (F) Lateral view tailbud stage; arrow indicates otic placode precursors expressing foo.