Scanning electron micrographs showing impaired embryonic eyelid closure in woe2 embryos. At E15.5 WT (A, A', A") and woe2 (B, B', B") embryos manifested open eyes of similar shape and with no distinct morphological difference. The accumulation of rounded peridermal cells at the leading edge of both WT (A', A") and woe2 (B', B") eyelids was evident (arrowhead). Differences between the WT and woe2 eyelids were evident at E16.5. The eyelids of WT embryos were completely fused (C, C', C") at the midline with flattened cells at the junction margins (C” arrow). In contrast, failure of eyelid closure was apparent in the eyes of woe2 mice at this time (D, D', D"). At this time point, very few peridermal cells were evident at the eyelid margin of woe2 eyelids (D” arrow).