The role of DNA repair genes in the formation of chromosome aberrations

The mechanisms of chromosome aberration formation have not yet been fully determined. With the current availability of primary cells from DNA repair deficient knock out mice and the introduction of multi-colour FISH, it is now possible to analyse in detail the formation of chromosome aberrations in the absence of repair genes from the main repair pathways. We have studied the induction of chromosome aberrations in mouse ES cells deficient in homologous recombination repair (Xrcc2-/-), single strand annealing (Ercc1-/-), non-homologous end joining (Ku70-/-) and transcription coupled repair (Csb-/-). Both low and high LET ionising radiation were used to introduce double strand breaks and the cells analysed at various times after treatment. We have examined chromosomal changes in mouse cells using Spectral karyotyping (SKY). Our results on the frequency and type of chromosome aberrations generated in these different repair deficient mouse cells will allow us to formulate models for chromosome aberration formation