Fig. 5. Delayed eye development in Fkbp8^-/- mutant embryos. (A) At E11.5, Fkbp8^-/- mutant eyes are smaller, have a thinner retinoblast layer and exhibit a hypo-pigmented pigment epithelium in the ventral region. (B) PAX2 (red) and PAX6 (green) immunofluorescence staining of optic vesicles at E10.5. PAX2 is ectopically expressed in the dorsal regions of the optic cup (white arrowheads) in the mutant. PAX6 expression appears comparable with wild type in the dorsal retina and in the lens primordium (white arrows), although lens morphogenesis is clearly delayed. (C) At E11.5, PAX6 expression is apparently reduced in the mutant retinoblast layer and lens. Background staining in the lens capsule and skin is due to non-specific binding of the secondary antibody. Scale bar: 30 µm in A,C; 50 µm in B.