No evidence for thermal transgenerational plasticity in metabolism when minimizing the potential for confounding effects

Environmental change may cause phenotypic changes that are inherited across generations through transgenerational plasticity (TGP). If TGP is adaptive, offspring fitness increases with an increasing match between parent and offspring environment. Here we test for adaptive TGP in somatic growth and metabolic rate in response to temperature in the clonal zooplankton Daphnia pulex. Animals of the first focal generation experienced thermal transgenerational ‘mismatch’ (parental and offspring temperatures differed), whereas conditions of the next two generations matched the (grand)maternal thermal conditions. Adjustments of metabolic rate occurred during the lifetime of the first generation (i.e. within-generation plasticity). However, no further change was observed during the subsequent two generations, as would be expected under TGP. Furthermore, we observed no tendency for increased juvenile somatic growth (a trait highly correlated with fitness in Daphnia) over the three generations when...

环境变化可诱发可跨代传递的表型改变，该现象被称为跨代可塑性（transgenerational plasticity, TGP）。若跨代可塑性具有适应性，则子代的适合度会随亲本与子代环境匹配程度的提升而升高。本研究以克隆型浮游动物大型溞（Daphnia pulex）为实验对象，检验其响应温度变化的体细胞生长与代谢率是否存在适应性跨代可塑性。首个目标世代的个体经历了温度跨代‘错配’处理，即亲本与子代的培养温度存在差异；而后续两个世代的培养条件均匹配（外）祖母的温度环境。首个目标世代的个体在其生命周期内发生了代谢率的调整，即代内可塑性；但在后续两个世代中未观察到代谢率出现进一步变化，这与跨代可塑性预期的结果相悖。此外，在三个世代的观测周期内，我们未发现幼体体细胞生长（该性状在大型溞中与个体适合度高度相关）存在提升的趋势，当……