Mechanism of photeractivation of pseudorabies virus.

Primary chick embryo cultures were able to photoreactivate ultraviolet-treated pseudorabies virus. Upon exposure to fluorescent light, infected or uninfected chick cells eliminated thymine dimers induced in their deoxyribonucleic acid by ultraviolet irradiation. In contrast, rabbit kidney cells did not photoreactivate the virus or eliminate thymine dimers. Thus, the capacity for photoreactivation appeared to be determined by the ability of the cell to eliminate thymine dimers.