Ionising radiation and mutation induction at mouse minisatellite loci. The story of the two generations.

The analysis of the effects of ionising radiation on germline mutations is limited by the number of offspring that need to be analysed following exposure to a dose, which is relevant to risk assessment in humans. We have developed a new experimental approach using hypervariable mouse expanded simple tandem repeat (ESTR) loci (minisatellites) which are both highly sensitive to ionising radiation and which permit changes in mutation rates to be detected in relatively small samples. Here, we review the progress made in validating the model, and the unexpected features it has revealed, including a novel form of radiation-induced genetic instability that can be transmitted from one generation to the next.