Life and Death without Telomerase: The Model.

, a model organism in telomere biology, has been instrumental in pioneering a comprehensive understanding of the molecular processes that occur in the absence of telomerase across eukaryotes. This exploration spans investigations into telomere dynamics, intracellular signaling cascades, and organelle-mediated responses, elucidating their impact on proliferative capacity, genome stability, and cellular variability. Through the lens of budding yeast, numerous sources of cellular heterogeneity have been identified, dissected, and modeled, shedding light on the risks associated with telomeric state transitions, including the evasion of senescence. Moreover, the unraveling of the intricate interplay between the nucleus and other organelles upon telomerase inactivation has provided insights into eukaryotic evolution and cellular communication networks. These contributions, akin to milestones achieved using budding yeast, such as the discovery of the cell cycle, DNA damage checkpoint mechanisms, and DNA replication and repair processes, have been of paramount significance for the telomere field. Particularly, these insights extend to understanding replicative senescence as an anticancer mechanism in humans and enhancing our understanding of eukaryotes' evolution.