Figure 1.

Conditional deletion of Six3 in the PLE causes severe lens phenotypes. Compared to age-matched control lenses (A–D), Six3^f/Δ;Le-Cre mutant eyes showed a range of lens defects at representative stages. (A′) At E12.5, the mutant eye appeared smaller, and the shape was abnormal. The shape of the retinal-pigmented epithelium (arrowhead) was defective. (B′) At E14.5, defects in the shape of the mutant eyes were consistently identified, and the lens (arrowhead) was extremely reduced. (C′) Three-month-old isolated mutant eyes exhibited obvious retinal defects such as irregular shape (arrow). The isolated lens was very small and degenerated and appeared to have cataracts (arrowhead). (D′) At 6 months, the eye lids of Six3^f/Δ;Le-Cre mutant mice were closed (arrowhead), suggestive of anophthalmia or microphthalmia. (E–P) H & E–stained sections of control and Six3^f/Δ;Le-Cre-mutant lenses. At E10.5, some mutants exhibited a smaller abnormal lens pit (arrows in F, G). (H) No lens pit (arrow) was present in those with the most severe phenotype, and the retina appeared to have been duplicated (arrowhead). At E12.5, some type I mutants exhibited slightly reduced lens vesicle (arrow in J), and some type II mutants showed greatly reduced ones (K). No lens vesicle was present in type III mutants (arrow in L). Similar phenotypic variations were seen at E14.5. The lens was smaller (N) or very reduced and abnormal (O, higher magnification in P). The lens stalk was frequently observed (arrow in N).