(How) do unicellulars age ?
Aging is nearly ubiquitous among living organisms. It is often considered a collateral damage or byproduct of the process of natural selection. However, the mechanistic causes of aging—what controls an organism's biological clock—remain unknown. In our group, we use yeast as a model system to disentangle the mechanisms that regulate the replicative lifespan of cells. To achieve this, we employ a microfluidic system that enables imaging of individual cells throughout their entire lifespan. Using this setup, we have demonstrated that early sporadic events related to genome integrity control are responsible for the replicative limit through a process of progressive degeneration. These findings provide a quantitative framework to formalize the aging process in a simple model system.