Data from: In a variable thermal environment selection favors greater plasticity of cell membranes in Drosophila melanogaster

Theory predicts that developmental plasticity, the capacity to change phenotypic trajectory during development, should evolve when the environment varies sufficiently among generations, owing to temporal (e.g., seasonal) variation or to migration among environments. We characterized the levels of cellular plasticity during development in populations of Drosophila melanogaster experimentally evolved for over three years in either constant or temporally variable thermal environments. We used two measures of the lipid composition of cell membranes as indices of physiological plasticity (a.k.a. acclimation): (1) change in the ratio of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) and (2) change in lipid saturation (number of double bonds) in cool (16ºC) relative to warm (25ºC) developmental conditions. Flies evolved under variable environments had a greater capacity to acclimate the PE/PC ratio compared to flies evolved in constant environments, supporting the prediction that environments with high among-generation variance favor greater developmental plasticity. Our results are consistent with the selective advantage of a more environmentally sensitive allele which may have associated costs in constant environments.

理论预测，发育可塑性（developmental plasticity）——即个体发育过程中改变表型轨迹的能力——会在世代间环境差异足够显著时演化，这种差异可来源于时间维度（如季节性）的环境变异，或是不同环境间的迁移。本研究对在恒定或时间可变热环境中经三年以上实验演化的黑腹果蝇（Drosophila melanogaster）种群，分析了其发育过程中的细胞可塑性水平。我们以细胞膜脂质组成的两项指标作为生理可塑性（acclimation，亦称驯化作用）的量化依据：其一为磷脂酰乙醇胺（phosphatidylethanolamine）与磷脂酰胆碱（phosphatidylcholine）的比值变化，其二为低温（16℃）相对于高温（25℃）发育条件下的脂质饱和度（双键数目）变化。与在恒定环境中演化的果蝇相比，在可变环境中演化的果蝇其PE/PC比值的驯化能力更强，这支持了“世代间环境变异度较高的环境更利于发育可塑性演化”的理论预测。本研究结果与“对环境更敏感的等位基因具有选择优势，且该等位基因在恒定环境中可能存在适应性代价”的观点相一致。