New clues to old yeast

The yeast Saccharomyces cerevisiae has been used as an experimental model f or the genetic and molecular dissecton of the aging process for the past de cade. This period has seen the implication of some 30 genes in yeast aging. These genes encode a wide array of biochemical functions. suggesting the p articipation of multiple molecular mechanisms of aging. However. four princ iples appear to be at play: metabolism, stress resistance. gene dysregulati on. and genetic instability. They units the broad physiological aspects of yeast aging with those in other species. Genes and environment are not the only players: stochastic change also appears important in determining life span. This element of chance provides opportunities for an integrative appr oach. which is beginning to appear in yeast aging research. (C) 2001 Elsevi er Science Ireland Ltd. All rights reserved.