Affiliations: 1) Cal State University, Fullerton; 2) Oregon State University
Keywords: h. selection; a. genome evolution
The evolutionary theory of aging proposes that the forces of natural selection start to decline after the first age of reproduction and continue to steadily decline until the last age of reproduction, where these forces stabilize at zero or become negligible. Past studies have used Drosophila melanogaster populations to show that gradually postponing the first age of reproduction, postpones the age at which the forces of natural selection begin to drop, and results in delayed aging and increased longevity. However, genomic studies involving longevity remain underpowered due to limitations in replication. Long-lived populations were created by progressively postponing the first age of reproduction from 14 days to 70 days. To maximize the statistical power of finding these candidate genes, we used ten replicate populations selected for increased longevity, maintained on 70-day discrete generation cycles, and ten replicate populations that are treated as matched controls, maintained on 14-day discrete generation cycles. We have completed twenty generations of laboratory selection for postponed reproduction. Populations selected for delayed reproduction had increased longevity, increased fecundity, increased desiccation and starvation resistance, and increased wet and dry body weight. Samples from these populations have been frozen/preserved for each generation of selection. We next aim to identify candidate genes involved in longevity using a genome-wide analysis of experimentally evolved short-lived and long-lived populations of D. melanogaster. Identifying regions of the genome that are differentiated between short and long-lived populations may provide candidate genes for human longevity.