Data from: Metabolome dynamics of diapause in the butterfly Pieris napi: distinguishing maintenance, termination and post-diapause phases

Diapause is a deep resting stage facilitating temporal avoidance of unfavourable environmental conditions that is used by many insects to adapt their life cycle to seasonal variation. Although considerable work has been invested in trying to understand each of the major diapause stages (induction, maintenance and termination), we know very little about the transitions between stages, especially diapause termination. Understanding diapause termination is critical for modelling and predicting spring emergence and winter physiology of insects, including many pest insects. In order to gain these insights we investigated metabolome dynamics across diapause development in pupae of the butterfly Pieris napi, which exhibits adaptive latitudinal variation in the length of endogenous diapause that is uniquely well characterized. By employing a time-series experiment we show that the whole-body metabolome is highly dynamic throughout diapause and differs between pupae kept at a diapause-terminating (low), or at a diapause-maintaining (high) temperature. We show major physiological transitions through diapause, separated temperature-dependent from temperature-independent processes and identified significant patterns of metabolite accumulation and degradation. Together the data show that while the general diapause phenotype (suppressed metabolism, increased cold tolerance) is established in a temperature-independent fashion, diapause termination is temperature-dependent and requires a cold signal. This revealed several metabolites that are only accumulated in diapause terminating conditions and degraded in a temperature-unrelated fashion during diapause termination. In conclusion, our findings indicate that some metabolites, in addition to functioning as e.g. cryoprotectants, are candidates for having regulatory roles as metabolic clocks or time-keepers during diapause.

滞育（diapause）是一类深度休眠状态，可帮助众多昆虫通过时序性规避不利环境条件，从而适配自身生命周期以响应季节变化。尽管学界已投入大量研究尝试解析滞育的三大核心阶段——诱导、维持与终止，但我们对各阶段间的转换机制仍知之甚少，尤以滞育终止为甚。解析滞育终止机制，对于模拟和预测包括诸多农业害虫在内的昆虫的春季羽化及冬季生理状态均至关重要。

为阐明此类科学问题，我们以暗脉菜粉蝶（Pieris napi）蛹为研究对象，探究其滞育发育全程的代谢组（metabolome）动态变化。该物种的内源滞育时长具有明确的适应性纬度梯度变异，且该特征已得到充分解析。借助时序实验，我们发现全身体代谢组在滞育过程中始终处于高度动态变化状态，且在滞育终止条件（低温）与滞育维持条件（高温）下培养的蛹之间存在显著差异。

研究揭示了滞育进程中的主要生理转变：将温度依赖型与温度非依赖型生理过程加以区分，并明确了代谢物积累与降解的显著特征模式。综合数据表明，尽管滞育的典型表型（代谢抑制、耐寒性提升）的建立不依赖温度，但滞育终止过程却具有温度依赖性，且需要低温信号触发。这一发现筛选出数种仅在滞育终止条件下积累，并在滞育终止过程中以非温度依赖方式降解的代谢物。

综上，本研究结果表明，部分代谢物除可发挥抗冻保护剂等功能外，还可能作为代谢时钟或时间调控因子，在滞育过程中行使调控功能。