Thomas D. Petes

I am interested in three types of mechanisms involved in regulating the stability of the yeast genome. First, in meiosis, certain regions of the chromosomes (hotspots) have high levels of DNA breaks and high levels of associated recombination. I am interested in what properties of the chromosome distinguish these regions. Second, my laboratory has investigated the genetic regulation of the stability of simple repetitive DNA sequences (microsatellites). Mutations that reduce the efficiency of DNA mismatch repair greatly destabilize microsatellites; comparable mutations in humans lead to certain types of familial cancer. The third research area concerns the ends (telomeres) of the yeast chromosomes. As in most other organisms, telomeres in yeast are composed of simple repetitive DNA sequences. We have identified mutations that reduce the length of the telomeric repeats, one of which (TEL1) is closely related to a human gene mutated in patients with ataxia telangiectasia.