Data from: An experimental test of the mutation-selection balance model for the maintenance of genetic variance in fitness components

AbstractDespite decades of research, the factors that maintain genetic variation for fitness are poorly understood. It is unclear what fraction of the variance in a typical fitness component can be explained by mutation-selection balance and whether fitness components differ in this respect. In theory, the level of standing variance in fitness due to mutation-selection balance can be predicted using the rate of fitness decline under mutation accumulation, and this prediction can be directly compared to the standing variance observed. This approach allows for controlled statistical tests of the sufficiency of the mutation-selection balance model, and could be used to identify traits or populations where genetic variance is maintained by other factors. For example, some traits may be influenced by sexually-antagonistic balancing selection, resulting in an excess of standing variance beyond that generated by deleterious mutations. We describe the underlying theory and use it to test the mutation-selection balance (MSB) model for three traits in Drosophila melanogaster. We find evidence for differences among traits, with MSB being sufficient to explain genetic variance in larval viability but not male mating success or female fecundity. Our results are consistent with balancing selection on sexual fitness components, and demonstrate the feasibility of rigorous statistical tests of the mutation-selection balance model., Usage notestrait_measurementsMeasures of three traits for MA lines and corresponding control lines ('MA_control'), and for lines derived from an outbred population ('standing'). The traits are male mating success ('male') female fecundity ('female') and larval viability ('viability'). Female fecundity measures are egg counts. Male mating success measures are number of females inseminated by focal males relative to competitors (total = focal + competitor). Viability measures are number of focal adults that developed relative to competitors (total = focal + competitor).摘要 尽管已有数十年的研究，维持适合度相关遗传变异的具体机制仍未被充分阐明。目前尚不明确，典型适合度组分的变异中，有多少比例可由突变选择平衡（mutation-selection balance）解释，且不同适合度组分在该方面是否存在差异。理论上，由突变选择平衡导致的适合度存留变异水平，可通过突变积累过程中的适合度下降速率进行预测，且该预测结果可与观测到的存留遗传变异直接对比。该方法可实现对突变选择平衡模型充分性的受控统计检验，还可用于识别那些由其他因素维持遗传变异的性状或种群。例如，部分性状可能受性拮抗平衡选择的影响，导致其存留遗传变异量超出有害突变所产生的变异水平。我们阐明了其背后的理论基础，并利用该理论对黑腹果蝇（Drosophila melanogaster）的3个性状开展了突变选择平衡（MSB）模型检验。我们发现不同性状间存在显著差异：突变选择平衡模型足以解释幼虫存活率的遗传变异，但无法解释雄性交配成功率与雌性繁殖力的遗传变异。本研究结果与性相关适合度组分受到平衡选择的假说一致，同时证明了对突变选择平衡模型开展严谨统计检验的可行性。 使用说明：性状测量数据 本数据集包含突变积累（Mutation Accumulation, MA）品系及其对应对照品系（命名为‘MA_control’），以及源自远交种群的品系（命名为‘standing’）的3个性状测量值。这3个性状分别为雄性交配成功率（‘male’）、雌性繁殖力（‘female’）与幼虫存活率（‘viability’）。 雌性繁殖力的测量指标为产卵数。雄性交配成功率的测量指标为：目标雄性相较于竞争者的受精雌性数量（总受精雌性数=目标雄性受精数+竞争者受精数）。幼虫存活率的测量指标为：相较于竞争者的目标成虫发育数量（总发育成虫数=目标成虫数+竞争者成虫数）。