DNA replication without telomerase leads to telomere shortening and induces replicative senescence. We found that in a telomerase-deficient budding yeast mutant, the volume of each telomere-shortened cell increased as its growth capacity decreased, and that this process was associated with changes in vacuolar morphology. Senescence-induced cell expansion required Mec1, a DNA damage-responsive kinase, but not vacuolar SNARE Vam3.
