Figure 2

Overexpression of Pax6 in the eye results in microphthalmia and retinal dysplasia. Horizontal sections through the eyes of wild-type and PAX77^+/+ eyes stained with cresyl violet. (A, G) E12.5, (B,H) E14.5, (C) E16.5, (D,I,J) E18.5, (E,K) P4, (F,L) P6. (A-F) As the eye develops the retina of PAX77^+/+ mice becomes progressively smaller than in wild-type mice. (B,C,D) A retrolental nodule (arrow) is present in the mutant eye from E14.5. (E,F) After birth, the vitreous chamber (*) has almost completely disappeared in the PAX77^+/+ eye and parts of the retina are in close contact with the lens. (H) Cells continuous with the pigmented epithelium (arrowhead) and the retina extend ectopically along the mutant optic stalk (arrow). (I) At E18.5, in the PAX77^+/+ eye the iris (arrow) is folded and in direct contact with the lens epithelium. (J) At E18.5 the retina is comprised of 2 well defined neuroblastic layers in mutant as in wild-type embryos. (K) At P4 the outer layer of the PAX77^+/+ retina starts to form rosettes (arrows). (L) At P6 PAX77^+/+ eyes display variable levels of rosetting of the outer nuclear layer. The PAX77^+/+ eye shown here displays severe rosetting. L, lens; OS, optic stalk; R, retina; OL, outer layer; IL, inner layer. Scale bars : A-F, 500 μm; G-L, 100 μm.