Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwakecho, Kyoto 606-8502, Japan.
Biol Lett. 2020 Apr;16(4):20200049. doi: 10.1098/rsbl.2020.0049. Epub 2020 Apr 8.
Extreme conditions are normal for animals living in harsh environments. These animals adapt to their habitats and can use difficult conditions by default. Organisms living in enclosed spaces, notably termites in decaying wood, experience low O and high CO gas conditions due to limited gas exchange and high insect density. Termite queens, in particular, reproduce in royal chambers deep inside the wood, wherein tens of thousands of individuals engage in social labour. Here, we demonstrate that royal chambers in termite nests have low O and high CO gas concentrations, which enhance egg production by queens. We identified a unique gas condition of royal chambers in the nest of the subterranean termite , which is characterized by low O (15.75%) and high CO (4.99%) concentrations. Queens showed significantly greater fecundity under the low O and high CO gas conditions in the royal chambers than under ambient gas conditions. Quantitative PCR analysis revealed that the royal chamber gas conditions significantly promoted the expression levels of the vitellogenin genes , and in queens compared with ambient gas conditions. This study highlights the adaptation of animals that live in closed habitats, which are hypoxic and hypercapnic as the result of their own metabolism, so as to have a high fitness in such environmental conditions.
极端条件对生活在恶劣环境中的动物来说是正常的。这些动物适应了它们的栖息地，可以默认使用困难的条件。生活在封闭空间中的生物，特别是腐朽木材中的白蚁，由于气体交换有限和昆虫密度高，会经历低氧和高二氧化碳气体条件。特别是白蚁蚁后，在木材深处的皇家巢穴中繁殖，那里有成千上万的个体从事社会劳动。在这里，我们证明了白蚁巢中的皇家巢穴中氧气含量低，二氧化碳含量高，这会促进蚁后的产卵。我们在地下白蚁的巢穴中发现了皇家巢穴的一种独特的气体条件，其特征是氧气含量低（15.75%），二氧化碳含量高（4.99%）。与环境气体条件相比，在皇家巢穴中的低氧和高二氧化碳气体条件下，蚁后的繁殖力显著增加。定量 PCR 分析显示，与环境气体条件相比，皇家巢穴气体条件显著促进了 和 基因在蚁后的表达水平。这项研究强调了生活在封闭栖息地的动物的适应能力，这些动物由于自身的新陈代谢而处于缺氧和高碳酸血症状态，因此在这种环境条件下具有很高的适应性。
