Life Span Extension of \u3ci\u3eDrosophila melanogaster\u3c/i\u3e: Genetic and Population Studies

During the past two decades, genetic studies of model organisms have been the most important tool underlying advances in understanding the biological basis of aging and longevity. Drosophila melanogaster, the geneticist\u27s fruit fly, is a model organism because it has been the focus of genetic studies for more than 90 years. This review argues that studies on D. melanogaster will make an especially important contribution to the field of aging and longevity at the intersection of research on genetics, complex traits, and fly populations. Five approaches have been used to study the genetics of longevity of D. melanogaster: (1) laboratory selection, (2) quantitative genetics, (3) transgenic overexpression, (4) mutation analysis, and (5) measurement of gene expression. The first two approaches attempt to decompose longevity as a complex character. The third and fourth approaches start by looking for major gene effects on life span. The fifth approach is emerging as part of a major advance in technology in which the expression of almost all genes in the genome can be measured at one time. Genetic research on aging and longevity using D. melanogaster has been reviewed previously (Arking 1987, 1988; Arking and Dudas 1989; Rose 1991; Curtsinger et al. 1995; Tower 1996; Stearns and Partridge 2001). The present chapter reviews the range of genetic approaches used to study aging and life span (length of life)