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 mutation accumulation 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.

功能健全的生物体必须维持代谢稳态。有害突变会削弱生物体功能，其机制至少部分与代谢功能受损相关。本研究通过突变积累实验，首次探究了秀丽隐杆线虫（Caenorhabditis elegans）代谢组的突变结构。研究发现，29种代谢物的浓度池在突变更易性上存在显著差异，这既体现在遗传方差的累积速率（即突变方差V_M）上，也体现在性状均值的变化速率（即突变偏倚ΔM）上。值得注意的是，部分代谢物的突变更易性远高于此前以相同实验范式研究过的其他性状。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，但主成分分析提供了强有力的证据：部分代谢物池存在遗传相关性，同时不同代谢物类群也具备独立进化的充足空间。对所有突变积累品系取平均后，主成分3（PC3）与相对适应度呈正相关，但基于“代谢物与适应度无关联”的模型，其赤池信息准则（AIC）得分与前者相差无几。