Aging: Genetics

Abstract

Aging is under genetic control and the genes, which ensure organism integrity and life span for successful reproduction, appear to have been highly conserved in evolution. These genes regulate the balance between survival and reproduction.

Keywords: aging; life span; pleiotropy; mutation accumulation; mortality

Figure 1.

Basic life history configuration of animals, for example, the tropical butterfly Bicyclus anynana. The figure represents the relative importance of genes affecting aging and longevity through time in a single cohort. At old age, the relative importance of longevity assurance genes is much increased relative to the contribution of deleterious mutations.

Figure 2.

(a) Survival (lx) and reproductive rate (mx), and (b) the probability of reproduction and proportion of reproduction remaining for an individual aged x, for a hypothetical nonaging population. The probability of reproduction at age x is taken as the product of lx and mx. The proportion of reproduction remaining can be taken as a measure for the strength of natural selection at age x. It appears that the strength of natural selection declines with age even in the absence of aging. Genes can escape the scrutiny of natural selection if their effects occur in the selection shadow.

Figure 3.

Change in the survival curve of human populations from a curve where few aging deaths occurred to a typical rectangular aging curve (redrawn with permission from Kandel et al., ).

Figure 4.

The enzymes superoxide dismutase and catalase are involved in a pathway that neutralizes reactive oxygen species (ROS). The figure is not exhaustive; other enzymes exist that have the same function, such as glutathione peroxidase.

Figure 5.

The insulin/IGF‐1 signaling pathway. In bold are the identified C. elegans genes that are homologous to the vertebrate (and D. melanogaster) genes. Some of the names of the components of the pathway are short‐hand notations.

Figure 6.

The role of the gonadal cells in the insulin/IGF‐1 signaling pathway and how it influences the life history of C. elegans. Active signals, genes, proteins and traits are shown in italics, and those that are inactive in bold (redrawn with permission from Leroi, ).

close

References

Kandel ER, Schwartz JH and Jessel TM (2000) Principles of Neural Science, 4th edn. New York, NY: McGraw‐Hill.

Kirkwood TBL and Holliday R (1979) The evolution of aging and longevity. Proceedings of the Royal Society of London, Series B: Biology 205: 531–546.

Leroi AM (2001) Molecular signals versus the loi de balancement. Trends in Ecological Evolution 16: 24–29.

Mackay TFC (2001) Quantitative trait loci in Drosophila. Nature Reviews 2: 11–20.

Medawar PB (1952) An Unsolved Problem in Biology. London, UK: HK Lewis.

Westendorp RGJ and Kirkwood TBL (1998) Human longevity at the cost of reproductive success. Nature 396: 743–746.

Williams GC (1957) Pleiotropy, natural selection, and the evolution of senescence. Evolution 11: 398–411.

Zwaan BJ, Bijlsma R and Hoekstra RF (1995) Direct selection on life‐span in Drosophila melanogaster. Evolution 49: 649–659.

Further Reading

Charlesworth B (1980) Evolution in Age‐structured Populations. Cambridge, UK: Cambridge University Press.

Clark WR (1999) A Means to an End. The Biological Basis of Aging and Death. New York, NY: Oxford University Press.

Finch CE (1990) Longevity, Senescence, and the Genome. Chicago, IL: The University of Chicago Press.

Guarente L and Kenyon C (2000) Genetic pathways that regulate aging in model organisms. Nature 408: 255–262.

Hamilton WD (1966) The moulding of senescence by natural selection. Journal of Theoretical Biology 12: 12–45.

Partridge L and Gems D (2002) Mechanisms of ageing: public or private? Nature Reviews Genetics 3: 165–175.

Rose MR (1991) Evolutionary Biology of Aging. New York, NY: Oxford University Press.

Zwaan BJ (1999) The evolutionary genetics of aging and longevity. Heredity 82: 589–597.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Zwaan, Bastiaan Johannes(Jan 2006) Aging: Genetics. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0005527]