Elevated mutation rates in the germline of Polκ mutant male mice

Mutation rates at two expanded simple tandem repeat (ESTR) loci were studied in the germline of DNA polymerase kappa (Polκ−/−) deficient mice. The spontaneous mutation rate in homozygous Polκ−/− males was significantly higher than in isogenic wild-type mice (Polκ+/+), but the ESTR mutation spectrum in Polκ−/− animals did not differ from that in Polκ+/+ males. We suggest that compromised translesion synthesis in Polκ−/− mice may result in replication fork pausing which, in turn, may affect ESTR mutation rate.