Research Center for Thermal and Entropic Science, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan,
Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan,
Zoolog Sci. 2024 Aug;41(4):400-406. doi: 10.2108/zs230093.
In holometabolous insects, the larval body is almost completely decomposed and reconstructed into the adult body during the pupal-pharate adult stages. Therefore, the total energetic cost of this process is a key thermodynamic quantity necessary for evaluating the benefit of their life history. Here, we measured whole-body thermal dissipation of single pupae of the fruit fly, , during the period from puparium formation to adult eclosion as a function of age, using a high-precision isothermal calorimeter at = 298 K. The mass-specific energy consumption during the period from the onset of larval-pupal apolysis to adult eclosion was determined to be 2.3 kJ/g for an individual of (adult) = 1.0 mg, while it was observed to follow Kleiber's law for individuals smaller than (adult) = 1.0 mg. During the pupal-pharate adult period, in addition to the U-shaped variation, several characteristic thermal dissipations related to various events, including somatic muscle contractions, ecdyses, pulsatile hormone secretion in a pharate adult, and vaporization of the exuvial fluid, were observed. The periodic bursts in the pharate adult stage grew exponentially, suggesting that the positive feedback in the metabolic system synchronized with the progression of development, making the energy consumption in this stage more efficient. The present study showed that high-precision calorimetry is a powerful and credible method for measuring not only the total energy spent during development but also the energy spent during every specific developmental event in an organism.
在完全变态的昆虫中，幼虫的身体在蛹化-成虫阶段几乎完全分解并重建为成虫身体。因此，这个过程的总能量成本是评估其生活史效益的关键热力学量。在这里，我们使用高精度等温量热仪在 298 K 下测量了果蝇单蛹从蛹壳形成到成虫羽化期间的整个身体热耗散，作为年龄的函数。从幼虫-蛹化皮离解开始到成虫羽化的个体能量消耗率为 2.3 kJ/g，个体大小为 （成虫）= 1.0 mg，而小于 （成虫）= 1.0 mg 的个体则遵循克莱伯定律。在蛹化-成虫期间，除了 U 形变化外，还观察到了与各种事件相关的几个特征热耗散，包括体壁肌肉收缩、蜕皮、成虫期脉冲激素分泌和蜕皮液蒸发。成虫期的周期性爆发呈指数增长，表明代谢系统中的正反馈与发育进程同步，使该阶段的能量消耗更加高效。本研究表明，高精度量热法是一种强大而可靠的方法，不仅可以测量发育过程中消耗的总能量，还可以测量生物体中每个特定发育事件所消耗的能量。
