Sox1−/−; Pax6Sey/+ lenses have a progressively degenerative phenotype. H&E stained wild-type (A), Pax6Sey/+ (B), Sox1+/−; Pax6Sey/+ (C), and Sox1−/−; Pax6Sey/+ (D) E15.5 lenses are shown. Distinct compartments for AEL, transition zone (tz), and fiber cells (fc) are evident in panels A–C. In panel D, yellow arrows indicate uniform appearance of cells around the lens perimeter and white arrows indicate the most anterior nuclei of the lens fiber cell compartment.