Gerontogenes: real or virtual?

The view that the life span of an organism is intrinsically limited and is largely species-specific necessarily involves certain notions of genetic elements of regulation. The term gerontogenes refers to any such genetic elements that are involved in the regulation of aging and life span. The existence of genes for programmed aging is generally discounted on the basis of evolutionary arguments against the notion of the adaptive nature of aging. It is suggested here that the concept of gerontogenes be linked with the idea of genes involved in homeostasis and longevity assurance, which is not contradictory to the nonadaptive nature of aging. Because these genes were not originally selected as real genes for aging, their involvement in aging is an emergent property making them virtual gerontogenes. Some experimental evidence is available that suggests that sets of genes involved in the maintenance and repair of various cellular functions are the primary candidates qualifying as virtual gerontogenes.