Research Paper Volume 8, Issue 11 pp 2827—2847

Figure 6. A model of telomere/telomerase associated genome instability affects yeast aging. Wild-type yeast cells have evolved to have regulated telomerase activity to maintain telomere homeostasis. In the absence of telomerase, telomeres gradually shrink to critically short ones that lead to either checkpoint activation and replicative senescence, or telomere recombination and accelerated replicative aging. When telomerase is constitutively active, the genome becomes less stable, and promotes chronological aging, which can be suppressed by down-regulation of TORC1/Sch9 pathway.