Introduction

The budding yeast Saccharomyces cerevisiae has served as an exemplary model of cellular aging for more than 50 years (Kaeberlein et al., 2001). Yeast provides several advantages over other model systems, including short life span, well-characterized genetic and molecular methods, low relative cost, cell-type homogeneity, and a vast organismal information base. Two distinct types of aging have been studied in yeast: replicative and chronological (Figure 18.1).

Figure 18.1. Two types of yeast aging. Replicative life span is defined as the number of daughter cells produced by a given mother cell prior to senescence. Chronological life span is defined as the length of time that a yeast cell can survive during quiescence. Chronological life span is typically measured by growing cells into stationary phase, which induces a starvation response and exit from the cell cycle.

Figure 18.1. Two types of yeast aging. Replicative life span is defined as the number of daughter cells produced by a given mother cell prior to senescence. Chronological life span is defined as the length of time that a yeast cell can survive during quiescence. Chronological life span is typically measured by growing cells into stationary phase, which induces a starvation response and exit from the cell cycle.

The replicative life span of a yeast cell refers to the number of daughter cells produced by a mother cell prior to senescence (Mortimer and Johnston, 1959); while chronological life span measures the time a yeast cell can survive under nonproliferative conditions (Fabrizio and Longo, 2003).

The ability to monitor both the replicative and chronological aging of a yeast cell is fortuitous, as it allows for independent analysis of the aging process in both dividing and nondividing cell types. Yeast replicative aging may serve as a suitable model for the aging of mitotically active cell types in multicellular eukaryotes, such as human stem cell populations. Chronological aging, on the other hand, models the aging process of postmitotic cell types like muscle and brain. The surprising degree of conservation, at least at the level of individual genes, between aging in yeast and aging in multicellular eukaryotes has made S. cerevisiae one of the premier model organisms in aging-related research.

Was this article helpful?

0 0
How To Add Ten Years To Your Life

How To Add Ten Years To Your Life

When over eighty years of age, the poet Bryant said that he had added more than ten years to his life by taking a simple exercise while dressing in the morning. Those who knew Bryant and the facts of his life never doubted the truth of this statement.

Get My Free Ebook


Post a comment