Data from: The mutational structure of metabolism in Caenorhabditis elegans

A properly functioning organism must maintain metabolic homeostasis. Deleterious mutations degrade organismal function, presumably at least in part via effects on metabolic function. Here we present an initial investigation into the mutational structure of the Caenorhabditis elegans metabolome by means of a mutation accumulation experiment. We find that pool sizes of 29 metabolites vary greatly in their vulnerability to mutation, both in terms of the rate of accumulation of genetic variance (the mutational variance, VM) and the rate of change of the trait mean (the mutational bias, ΔM). Strikingly, some metabolites are much more vulnerable to mutation than any other trait previously studied in the same way. Although we cannot statistically assess the strength of mutational correlations between individual metabolites, principal component analysis provides strong evidence that some metabolite pools are genetically correlated, but also that there is substantial scope for independent evolution of different groups of metabolites. Averaged over MA lines, PC3 is positively correlated with relative fitness, but a model in which metabolites are uncorrelated with fitness is nearly as good by Akaike's Information Criterion (AIC).

功能健全的生物体必须维持代谢稳态（metabolic homeostasis）。据推测，有害突变损害生物体机能的机制至少部分源于对代谢功能的负面影响。本研究借助突变积累实验（mutation accumulation experiment），对秀丽隐杆线虫（Caenorhabditis elegans）代谢组（metabolome）的突变结构展开初步探究。我们发现，29种代谢物的池浓度在突变更易感程度上存在显著差异，这既体现在遗传方差的累积速率（即突变方差，mutational variance, V_M）上，也体现在性状均值的变化速率（即突变偏倚，mutational bias, ΔM）上。令人瞩目的是，部分代谢物的突变更易感程度远高于此前采用相同研究手段分析过的其他性状。尽管我们无法通过统计学方法评估单个代谢物间的突变相关性强弱，但主成分分析（principal component analysis）提供了强有力的证据：部分代谢物池存在遗传相关性，同时不同类群的代谢物也拥有可观的独立进化空间。对所有突变积累（MA）品系取平均值后，主成分3（PC3）与相对适应度呈正相关；但依据赤池信息准则（Akaike's Information Criterion, AIC），"代谢物与适应度无关联"的模型拟合效果几乎与之不相上下。