Abstract
Werner's syndrome (WS) is a human disease with manifestations resembling premature aging. The gene defective in WS,
WRN
, encodes a DNA helicase. Here, we describe the generation of mice bearing a mutation that eliminates expression of the C terminus of the helicase domain of the WRN protein. Mutant mice are born at the expected Mendelian frequency and do not show any overt histological signs of accelerated senescence. These mice are capable of living beyond 2 years of age. Cells from these animals do not show elevated susceptibility to the genotoxins camptothecin or 4-NQO. However, mutant fibroblasts senesce approximately one passage earlier than controls. Importantly,
WRN
−/−
;
p53
−/−
mice show an increased mortality rate relative to
WRN
+/−
;
p53
−/−
animals. We consider possible models for the synergy between
p53
and
WRN
mutations for the determination of life span.
