Correlation between DNA repair of embryonic fibroblasts and different life span of 3 inbred mouse strains.

Primary mouse fibroblast cultures were established from 10 day old embryos of 3 inbred strains with a genetically determined different life expectancy. The capacity for unscheduled DNA synthesis following u.v. irradiation was studied in these cells at various passage levels of the in vitro ageing process. The mouse fibroblasts show considerable repair synthesis corresponding to the duration of exposure time. The capacity for induction of unscheduled DNA synthesis was different in the cells of each strain and correlated to the natural life span of the animal. In each case, however, the ability to perform repair synthesis was subjected to an age-associated decline, although semiconservative DNA synthesis and proliferative potential of the cells was not changed until the cultures entered phase III passages.