Analysis of thymidine incorporation in the DNA of chick embryonic lens epithelium and fibers irradiated with ultraviolet light

Abstract

We have studied the effect of 254 nm ultraviolet radiation on the incorporation of [ 3 H]thymidine in chick embryonic lenses cultured in vitro. We find a u.v.-dose-dependent delay in DNA synthesis in intact lenses which is followed by its resumption at rates comparable to controls although the absolute level of incorporation decreases with increasing dose of u.v. When lens epithelium and fibers are cultured and u.v.-irradiated separately, only the former carry out unscheduled DNA synthesis. Lens fiber cells do not incorporate [ 3 H]thymidine regardless of whether or not these were treated with ultraviolet light.