Chronic low-dose lesion equilibrium along genes: measurement, molecular epidemiology, and theory of the minimal relevant dose.

Spontaneous mutations seem to be caused almost entirely by endogenous lesions. The pattern of these lesions along a gene represents an equilibrium between damage and repair. A pattern can be measured using ligation-mediated PCR (polymerase chain reaction) and a large chronic dose of a suspected endogenous mutagen. A study using dimethylsulfate-induced 7meGuanine lesions indicates that the exogenously induced pattern depends on how methyl purine glycosylase recognizes sequence context and, for this lesion, the pattern may be independent of the mutagen's dose.