Models of accelerated ageing can be informative about the molecular mechanisms of ageing and/or age-related pathology.

During the past ten years considerable progress has been made in discovering genes that regulate longevity by identifying single gene mutations that lead to increased longevity. The initial success in nematodes was quickly followed by comparable success in fruit flies and mice. In contrast, mutations that cause a decrease in longevity have been largely discounted as unlikely to be informative about aging mechanisms. However, the recent creation of several mutant mouse models that develop a variety of aging-like phenotypes and die prematurely, suggests that such models may be useful in understanding aging mechanisms, particularly as they relate to progressive tissue and organ dysfunction. A possible common feature of these models may be an imbalance between loss of cells by apoptosis and subsequent cell replacement, leading gradually to a net loss of cells in multiple tissues.