Fig. 6. Expression patterns of Otx2 and Msx1 in various Shh, Gli2 and Gli3 compound mutants. (A-J) Expression patterns of Otx2 (A-E) and Msx1 (F-J) in the developing cochlear duct of Shh;Gli3 compound mutants at 12.5 dpc. (A) Otx2 is expressed in the lateral wall of the developing cochlear duct in wild type. (B) There is no expression of Otx2 in Shh^-/- mutants. (C) Otx2 is expressed in the ventral-lateral wall of the Shh^-/-;Gli3^+/- inner ears. (D,E) Strong Otx2 expression is observed in the ventral-lateral wall of Shh^-/-;Gli3^-/- (D) and Gli3699 (E) embryos. (F) Msx1 is expressed at the distal tip of the cochlear duct (arrow) and the endolymphatic duct of wild-type embryos. (G,H) In Shh^-/- (G) or Shh^-/-;Gli3^+/- (H) embryos, in which cochlear duct is not developed, Msx1 expression is not observed ventrally (asterisk). (I,J) Even though the cochlear duct is partially formed in Shh^-/-;Gli3^-/- (I) and Gli3699 (J) mutants, Msx1 is not observed, indicating that these cochlear ducts are missing the distal region. (K-R) Expression patterns of Otx2 (K-N) and Msx1 (O-R) in the developing cochlear duct of Gli2;Gli3 compound mutants at 12.5 dpc. Strong Otx2 expression in the cochlear duct is shown in all the Gli2;Gli3 compound mutants (K-N). Msx1 expression at the distal tip of the cochlear duct is found (arrows) in Gli2^+/-;Gli3^+/- (O), Gli2^-/-;Gli3^+/- (P) and Gli2^+/-;Gli3^-/- (Q) embryos, but not in Gli2^-/-;Gli3^-/- double mutants (asterisk, R). For abbreviations refer to Fig. 1. Scale bar: 100 µm.