Histology.

Histological sections from embryonic day 17.5 (E.17.5) till postnatal day 14 (P14) are given in an overview (left panel) and in a higher magnification of the anterior/equatorial region in the right panel of wild types, heterozygous and homozygous mutants. Cataract formation starts after birth in the homozygous mutants only. The first signs are vacuoles in the posterior cortical region of newborn mice (P1, red arrows), which are compressed later by the growing lens (P7, red arrow). Finally, they give rise to the sharp boundaries in the cortical region (P14, red arrow) being observed in the isolated lenses (Fig 2A). The bars indicate the magnification of the individual figures; the lenses of the homozygous mutants are shown in an even higher magnification than the heterozygotes to demonstrate the pathological processes in more detail.