Longevity, genes, and aging: A view provided by a genetic model system

The genetic analysis of aging in the yeast Saccharomyces cerevisiae has rev ealed the importance of metabolic capacity, resistance to stress, integrity of gene regulation, and genetic stability for longevity. A balance between these life maintenance processes is sustained by the RAS2 gene, which chan nels cellular resources among them. This gene cooperates with mitochondria and PHB1 in metabolic adjustments important for longevity. It also modulate s stress responses. Transcriptional silencing of heterochromatic regions of the genome is lost during aging, suggesting that gene dysregulation accomp anies the aging process. There is evidence that this age change plays a cau sal role. Aging possesses features of a nonlinear process, and it is likely that application of nonlinear system methodology to aging will be producti ve. (C) 1999 Elsevier Science Inc. All rights reserved.