Telomere-driven mutational processes in yeast.

Telomeres are part of the system that guards genome integrity in eukaryotes, protecting linear chromosomes from fusions and degradations. The protective functions of telomeres are put at risk in physiological situations where telomeres shorten and trigger replicative senescence. Current models suggest that when telomeres shorten, combined actions of the DNA damage signalling network, DNA repair pathways, and the mechanics of mitosis result in translocations, gene losses, and aneuploidy. In yeasts, many of these processes (signalling, repair, mitosis) can be molecularly dissected because telomerase can be experimentally removed to enable detection of early and rare events. Here we review recent findings on telomere-driven mutational processes in yeast models and discuss how telomere dynamics may contribute to genome evolution.