Data from: Genomic basis of life history evolution in Drosophila melanogaster

Natural diversity in aging and other life history patterns is a hallmark of organismal variation. Related species, populations, and individuals within populations show genetically based variation in life span and other aspects of age-related performance. Population differences are especially informative because these differences can be large relative to within-population variation and because they occur in organisms with otherwise similar genomes. We used experimental evolution to produce populations divergent for life span and late-age fertility and then used deep genome sequencing to detect sequence variants with nucleotide-level resolution. Several genes and genome regions showed strong signatures of selection, and the same regions were implicated in independent comparisons, suggesting that the same alleles were selected in replicate lines. Genes related to oogenesis, immunity, and protein degradation were implicated as important modifiers of late-life performance. Expression profiling and functional annotation narrowed the list of strong candidate genes to 38, most of which are novel candidates for regulating aging. Life span and early-age fecundity were negatively correlated among populations; therefore the alleles we identified also are candidate regulators of a major life-history trade-off. More generally, we argue that hitchhiking mapping can be a powerful tool for uncovering the molecular bases of quantitative genetic variation.

衰老及其他生活史模式的自然多样性是生物体变异的标志性特征。近缘物种、种群以及种群内的个体在寿命及其他与衰老相关的机能表现上存在基于遗传的变异。种群间的差异尤其具有研究价值，因为相较于种群内的变异，这类差异往往更为显著，且这些差异存在于基因组整体背景相似的生物体中。本研究通过实验进化技术构建了寿命与晚年生育力存在显著分化的种群，随后借助深度基因组测序以核苷酸级分辨率检测序列变异。多个基因及基因组区域呈现出强烈的选择信号，且独立对比分析均指向同一类基因组区域，这表明重复实验株系中被选择的是同一类等位基因。与卵子发生、免疫及蛋白质降解相关的基因被证实为晚年机能表现的重要修饰因子。通过表达谱分析与功能注释，本研究将候选强基因筛选至38个，其中绝大多数均为调控衰老的全新候选基因。种群间寿命与早期生育力呈负相关；因此本研究鉴定出的等位基因同时也是调控核心生活史权衡的候选调控因子。更广泛而言，本研究认为搭便车作图（hitchhiking mapping）可作为揭示数量遗传变异分子基础的高效工具。