Optimal Scaling of Critical Size for Metamorphosis in the Genus Drosophila
Optimal Scaling of Critical Size for Metamorphosis in the Genus Drosophila
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DOI：
10.1016/j.isci.2019.09.033
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发表时间：
2019-10-25
期刊：
影响因子：
5.8
通讯作者：
Nishimura, Takashi
中科院分区：
文献类型：
--
作者：
Hironaka, Ken-ichi;Fujimoto, Koichi;Nishimura, Takashi
青少年必须达到一个临界的身体尺寸才能成为成熟的成年人。人们已经研究了临界大小的分子决定因素，但临界大小的进化重要性仍不清楚。在这里，使用9种苍蝇，我们证明了有机体大小的种间差异可以完全用物种特有的临界大小来解释。观察到的临界大小的变化定量地符合生活史模型预测的种间比例关系，该模型假设临界大小介导了幼年和成年组织之间的能量分配切换。生长持续时间和生长速度之间的反向关系抵消了它们对最终尺寸的贡献，从而解释了临界尺寸缩放的机理。最后，我们表明，生长周期的进化变化可以追溯到蜕皮激素动态的标度。我们的结论是，临界大小自适应地优化能量分配，并在生物体大小确定中发挥核心作用。
Juveniles must reach a critical body size to become a mature adult. Molecular determinants of critical size have been studied, but the evolutionary importance of critical size is still unclear. Here, using nine fly species, we show that interspecific variation in organism size can be explained solely by species-specific critical size. The observed variation in critical size quantitatively agrees with the interspecific scaling relationship predicted by the life history model, which hypothesizes that critical size mediates an energy allocation switch between juvenile and adult tissues. The mechanism underlying critical size scaling is explained by an inverse relationship between growth duration and growth rate, which cancels out their contributions to the final size. Finally, we show that evolutionary changes in growth duration can be traced back to the scaling of ecdysteroid hormone dynamics. We conclude that critical size adaptively optimizes energy allocation, and has a central role in organism size determination.