Aging mechanisms in fruit flies

Abstract

Genetic analysis of Drosophila has provided evidence in support of two proposed evolutionary genetic mechanisms of aging: mutation accumulation and antagonistic pleiotropy. Both mechanisms result from the lack of natural selection acting on old organisms. Analyses of large numbers of files have revealed that mortality rates do not continue to rise with age as previously thought, but plateau at advanced ages. This phenomenon has implications both for models and for definitions of aging, and may be explained by the evolutionary theories. The physiological processes and genes most relevant to aging are being identified using Drosophila lines selected in the laboratory for postponed senescence. Oxidative stress and insufficient metabolic reserves/capacity may be particularly important factors in limiting the fruitfly lifespan. Genes which exhibit aging-related changes in expression are now being identified. Transgenic files are being used to analyze the mechanisms of such aging-related gene expression, and to test the effects of specific genes on aging and aging-related deterioration.

Analysis of the effects of inbreeding on lifespan and starvation resistance in Drosophila melanogaster

“…2). According to Tower (1996) adult D. melanogaster lifespan averages 40 days at 25°C. Hence, the observed longevity of the outbred flies is within the range of normal adult survival in this species under standard laboratory conditions.…”

Oxidative stress tolerance and longevity in Arabidopsis: the late‐flowering mutant gigantea is tolerant to paraquat

“…A positive correlation between lifespan and antioxidant capacity has been reported in yeast, Neurospora, Caenorhabditis elegans, Drosophila melanogaster, and mammals (Fleming et al, 1992;Jazwinski, 1996;Kennedy et al, 1995;Lithgow and Kirkwood, 1996;Martin et al, 1996;Tower, 1996). Critical support for the idea that stress tolerance is related to extended life-span comes from the observation that most C. elegans longevity mutants are resistant to oxidative stress, thermal stress, and UV irradiation with the degree of tolerance often being proportional to the extention of life-span (Murakami and Johnson, 1996).…”

The Reliability Theory of Aging and Longevity

“…Moreover, he found that at advanced ages mortality rates increase less rapidly than an exponential function, thus forestalling two centuries ago the recent fuss over &&late-life mortality deceleration'' (Fukui et al, 1993(Fukui et al, , 1996Khazaeli et al, 1996;Vaupel et al, 1998;Partridge & Mangel, 1999), &&mortality leveling o! '' (Carey & Liedo, 1995;Clark & Guadalupe, 1995;Vaupel et al, 1998), and &&late-life mortality plateaus'' (Mueller & Rose, 1996;Tower, 1996;Pletcher & Curtsinger, 1998;Wachter, 1999). For a more in-depth analysis of the previous extensive studies on mortality leveling-o!…”