Abstract

The problem we discuss is whether mammalian cells possess genes whose expression is specifically enhanced by DNA damage in order to cope with the damage. The paradigm is the SOS response in E. coli. We conclude that there is compelling evidence that DNA‐damaging agents do affect gene expression, and that mutation frequencies are increased, but proof that a repair process per se is induced remains elusive. We offer here the hypothesis that recognition of the presence of DNA damage by poly(ADPribose) polymerase effects preprogrammed changes in gene expression.