title: Aging yeast cells undergo a sharp entry into senescence unrelated to the loss of mitochondrial membrane potential.
abstract: In budding yeast, a mother cell can produce a finite number of daughter cells before it stops dividing and dies. Such entry into senescence is thought to result from a progressive decline in physiological function, including a loss of mitochondrial membrane potential (ΔΨ). Here, we developed a microfluidic device to monitor the dynamics of cell division and ΔΨ in real time at single-cell resolution. We show that cells do not enter senescence gradually but rather undergo an abrupt transition to a slowly dividing state. Moreover, we demonstrate that the decline in ΔΨ, which is observed only in a fraction of cells, is not responsible for entry into senescence. Rather, the loss of ΔΨ is an age-independent and heritable process that leads to clonal senescence and is therefore incompatible with daughter cell rejuvenation. These results emphasize the importance of quantitative single-cell measurements to decipher the causes of cellular aging.
authors: Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, 67400 Illkirch Cedex, France.
authors: Steffen
authors: S
authors: Fehrmann
authors: Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, 67400 Illkirch Cedex, France.
authors: Camille
authors: C
authors: Paoletti
authors: Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, 67400 Illkirch Cedex, France.
authors: Youlian
authors: Y
authors: Goulev
authors: LJC, ENS Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors: Andrei
authors: A
authors: Ungureanu
authors: LBMC, ENS Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors: Hugo
authors: H
authors: Aguilaniu
authors: Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, 67400 Illkirch Cedex, France. Electronic address: charvin@igbmc.fr.
authors: Gilles
authors: G
authors: Charvin
mesh_terms: D049109:Cell Proliferation; D053078:Membrane Potential, Mitochondrial; D044085:Microfluidics / Q000379:methods; D008928:Mitochondria / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000502:physiology