Chinese hamster ovary (CHO) cells exposed to ultraviolet(UV)-light and methyl methanesulfonate (MMS), analysed by alkaline sucrose gradient sedimentation, showed an interruption of DNA replication. In UV-irradiated cells, dose-dependent response appea...
Chinese hamster ovary (CHO) cells exposed to ultraviolet(UV)-light and methyl methanesulfonate (MMS), analysed by alkaline sucrose gradient sedimentation, showed an interruption of DNA replication. In UV-irradiated cells, dose-dependent response appeared; at low fluences below 1.42J/m2 the inhibition of replicon initiation was caused and as the fluence increased the effect on replicon initiation was masked by the inhibitory effects on strand-elongation and joining. MMS also showed the inhibitory effects in dose dependent manner at both processes of replicon initiation and chain elongation of DNA. treatment with UV and MMS concomitantly resulted in the additive inhibition effects of DNA replication.