Fig. 6. PAX2 localisation in the developing eye. Frontal sections of wild-type (A-D) and Otx1^-/-; Otx2^+/-+/- (E-F) mice at E10.5 (A,C,E) and E12.5 (B,D,F) were immunostained with antiserum against PAX2. Otx2 expression was localised in wild-type embryos (A,B) with a digoxigenin-labelled probe. Note that Otx2 and PAX2 colocalise only in a few cells at the boundary of the two expression domains (inset in A, B). In Otx1^-/-; Otx2^+/- mice PAX2 expression is extended into the neural NR (compare C and E) and the RPE (D,F) territories. lv, lens vesicle; nr, neural retina; os, optic stalk. Bar: 150 µm (A,C,E), and 200 µm (B,D,F).