Fig. 5. Gene patterning in the OC of E12.5 Otx-deficient mice. The expression domains of Six3 (A,B), Pax6 (C,D) and Pax2 (E,F) in wild type (A,C,E,G) and Otx1^-/-; Otx2^+/- (B,D,F,H) mice are illustrated with dark-field views of frontal paraffin sections hybridised with radioactive probes (A-F). Corresponding cytoarchitecture is showed with DIC images in G and H. Note the ‘ectopic’ expression of Pax6 and Six3 in the outer layer of the OC (B,D) and the extension of the Pax2 domain (F) in Otx1^-/-; Otx2^+/- embryos. enr, ectopic neural retina; lv, lens vesicle; nr, neural retina; os, optic stalk; pe, retina pigment epithelium. Bar, 200 µm.