Some commonly used cancer drugs not only generate mutations in treated mice, but scar the genomes of their offspring as well.

Radiation is known to cause genomic instability, leading to mutations that are passed down to the first- and even second-generation progeny of exposed mice. Colin Glen and Yuri Dubrova at the University of Leicester, UK, reasoned that the same could be true of DNA-damaging chemotherapies.

The duo tested three such drugs in male mice at concentrations similar to those used in humans, and found that the offspring of exposed mice harboured up to twice as many mutations as their exposed parent at the genome location studied. Moreover, mutations were present in both the copy of the genome inherited from the exposed parent and that from the unexposed parent.

Proc. Natl Acad. Sci. USA http://dx.doi.org/10.1073/pnas.1119396109 (2012)