The molecular weights of pulse labeled DNA at various times after UV-irradiation declined and then recovered. The rate recovery at which their ability to synthesize control size DNA was a function of replicon size; normal human cells with small replic...
The molecular weights of pulse labeled DNA at various times after UV-irradiation declined and then recovered. The rate recovery at which their ability to synthesize control size DNA was a function of replicon size; normal human cells with small replicons recovered more rapidly than SV40 transformed cells with large replicons At low numbers of UV-lesions per replicon in normal cells, inhibition of replicon initiation was the predominant response; at higher numbers of lesions per replicons in SV40 transformed cells, blockage of chain growth was the predominant response. These results indicate that replicon size determines, in part, the response of DNA replication to UV damage.