title: A quantitative analysis of UV-induced cell killing.
abstract: A quantitative hypothesis is developed, analogous to a previously developed model for ionising radiation, to describe the induction of eukaryotic cell killing by ultraviolet light. The hypothesis makes use of a recent proposal which suggests that pairs of dimers close to, and on either side of, a replication termination site provide long-lived blocks to replication, by suggesting that these 'paired dimer' lesions are potentially lethal. The hypothesis contains two crucial elements: (i) two dimers form the crucial lesion, and (ii) the paired dimer lesion is only recognised at the DNA-replication subsequent to exposure. Cell survival is predicted to be related to the square of the UV exposure and several sets of data are shown to be in good agreement with this prediction for surviving fractions down to 5% at least. It is shown that making use of a known molecular repair process, excision repair, the hypothesis gives a logical explanation for the unusual effects of UV fractionation reported previously for both exponentially growing cells and also for stationary cells. The hypothesis is amenable to further experimental verification.
mesh_terms: D002470:Cell Survival / Q000528:radiation effects; D002477:Cells / Q000528:radiation effects*; D005057:Eukaryotic Cells / Q000528:radiation effects*; D008954:Models, Biological; D011740:Pyrimidine Dimers; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D011740:Pyrimidine Dimers