Figure 3.

AP-2α KO eye defects begin at OV stage. (A–J) Coronal H&E-stained paraffin sections of wild-type (A–D) and AP-2α KO (E–J) embryo heads at the stages indicated. (A, E) Red asterisks denote the mispositioning of the AP-2α KO OV at E9.5, which was not oriented correctly with respect to the surface ectoderm. (B, F) Black arrows point to regions of the wild-type and AP-2α KO outer OC that are similar in thickness, whereas orange arrowheads point to regions of presumptive RPE adjacent to the optic stalk that are thickened in AP-2α KOs compared with controls. (C, D, G–J) Although the RPE formed a clear monolayer at E11.5 and onwards in wild-type eyes (black arrows in C, D), regions of the outer OC layer in AP-2α KOs were visibly thickened in both the dorsal OC (blue arrowheads in G–J) and ventral OC (black arrowheads in G, H). Red arrows in I, J show AP-2α KO eyes with an underdeveloped ventral retina. Scalebars, 100 µm.