Fig. 5. Dorsoventral polarity markers are normally expressed in Bmp7 null optic cups. Frontal vibratome sections from wild-type (A,C,E) and Bmp7-null (B,D,F) optic cups were hybridised with probes specific for Vax2 (A,B), Bmp4 (C,D) and Raldh3 (E,F). The pattern of expression of both ventral (Vax2) and dorsal (Bmp4) markers is unchanged in the mutant. Expression levels for Raldh3 are reduced in the mutant, particularly at the presumptive RF (arrows in E,F). Scale bar: 50 µm.