Diverse conditions support near-zero growth in yeast: Implications for the study of cell lifespan
Authors:Jordan Gulli1, Emily Cook1, Eugene Kroll1, Adam Rosebrock2,3, Amy Caudy2 and Frank Rosenzweig1
doi: 10.15698/mic2019.09.690
Volume 6, pp. 397 to 413, published 20/08/2019.
1 School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332.
2 Donnelly Centre for Cellular and Biological Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
3 Present address: Stony Brook School of Medicine, Stony Brook University, Stony Brook, NY 11794.
Keywords:
baker’s yeast, chronological lifespan (CLS), near-zero growth, starvation, giant yeast colonies, retentostats, encapsulation, immobilized cell reactors.
Corresponding Author(s):
Conflict of interest statement:
The authors declare no conflict of interest.
Please cite this article as:
Jordan Gulli, Emily Cook, Eugene Kroll, Adam Rosebrock, Amy Caudy and Frank Rosenzweig (2019). Diverse conditions support near-zero growth in yeast: Implications for the study of cell lifespan. Microbial Cell 6(9): 397-413. doi: 10.15698/mic2019.09.690
© 2019 Gulli et al. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduc-tion in any medium, provided the original author and source are acknowledged.
Abstract:
Baker’s yeast has a finite lifespan and ages in two ways: a mother cell can only divide so many times (its replicative lifespan), and a non-dividing cell can only live so long (its chronological lifespan). Wild and laboratory yeast strains exhibit natural variation for each type of lifespan, and the genetic basis for this variation has been generalized to other eukaryotes, including metazoans. To date, yeast chronological lifespan has chiefly been studied in relation to the rate and mode of functional decline among non-dividing cells in nutrient-depleted batch culture. However, this culture method does not accurately capture two major classes of long-lived metazoan cells: cells that are terminally differentiated and metabolically active for periods that approximate animal lifespan (e.g. cardiac myocytes), and cells that are pluripotent and metabolically quiescent (e.g. stem cells). Here, we consider alternative ways of cultivating Saccharomyces cerevisiae so that these different metabolic states can be explored in non-dividing cells: (i) yeast cultured as giant colonies on semi-solid agar, (ii) yeast cultured in retentostats and provided sufficient nutrients to meet minimal energy requirements, and (iii) yeast encapsulated in a semisolid matrix and fed ad libitum in bioreactors. We review the physiology of yeast cultured under each of these conditions, and explore their potential to provide unique insights into determinants of chronological lifespan in the cells of higher eukaryotes.