Pax6 is essential for normal development of the eye, brain, and pancreas. This gene is known as the "master regulator of eye development." It has been shown that mis-expression of Pax6 in flies results in formation of ectopic eyes. Eye development is extremely sensitive to Pax6 levels. Reduction in the levels of Pax6 expression results in severe eye phenotype: aniridia in humans and small eye in mice and rats. Therefore, Pax6 must play a critical role in the proliferation, differentiation, and apoptosis in corneal epithelial progenitor cells.

We found that overexpressing pax6 inhibits proliferation of RCE cells. In cells transfected with the pax6 gene, PCNA levels decreased. Pax6 levels increased in RCE cells exposed to UV radiation. In transiently transfected cells, RCE cells overexpressing pax6 had greater sensitivity to ultraviolet radiation. A tetracycline-inducible pax6 expression cell line was developed to control pax6 expression for future studies.