Along the Trajectory to Understanding Cellular Aging: More Lessons from Yeast.

Aging is a universal biological phenomenon that affects all biological systems. It is characterized by the inability to remain in a balanced physiological state, leading to a functional decline of the organism and, in metazoa, an increased risk of age-related diseases. Identifying causal drivers of aging is a major challenge at the cellular level, but in the model organism Saccharomyces cerevisiae, recent technical advances enabling the full observation of its replicative lifespan have revealed a heterogeneous aging process characterized by unique temporal and functional dependencies between cellular subprocesses. Specifically, cellular aging progresses through different trajectories, representing successive stages of homeostatic loss throughout the organism's life. In this perspective, we review the latest cellular principles as learned from S. cerevisiae that are providing a better understanding of how cellular aging progresses in metazoa.