Chown Steven L, Gibbs Allen G, Hetz Stefan K, Klok C Jaco, Lighton John R B, Marais Elrike
Spatial, Physiological, and Conservation Ecology Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
Physiol Biochem Zool. 2006 Mar-Apr;79(2):333-43. doi: 10.1086/499992. Epub 2006 Feb 2.
Many adult and diapausing pupal insects exchange respiratory gases discontinuously in a three-phase discontinuous gas exchange cycle (DGC). We summarize the known biophysical characteristics of the DGC and describe current research on the role of convection and diffusion in the DGC, emphasizing control of respiratory water loss. We summarize the main theories for the evolutionary genesis (or, alternatively, nonadaptive genesis) of the DGC: reduction in respiratory water loss (the hygric hypothesis), optimizing gas exchange in hypoxic and hypercapnic environments (the chthonic hypothesis), the hybrid of these two (the chthonic-hygric hypothesis), reducing the toxic properties of oxygen (the oxidative damage hypothesis), the outcome of interactions between O(2) and CO(2) control set points (the emergent property hypothesis), and protection against parasitic invaders (the strolling arthropods hypothesis). We describe specific techniques that are being employed to measure respiratory water loss in the presence or absence of the DGC in an attempt to test the hygric hypothesis, such as the hyperoxic switch and H(2)O/CO(2) regression, and summarize specific areas of the field that are likely to be profitable directions for future research.
许多成年和滞育蛹期昆虫在三相不连续气体交换循环（DGC）中进行不连续的呼吸气体交换。我们总结了DGC已知的生物物理特征，并描述了当前关于对流和扩散在DGC中的作用的研究，重点是对呼吸水分流失的控制。我们总结了DGC进化起源（或者非适应性起源）的主要理论：呼吸水分流失的减少（湿度假说）、在低氧和高碳酸环境中优化气体交换（冥土假说）、这两者的混合（冥土 - 湿度假说）、降低氧气的毒性（氧化损伤假说）、O₂和CO₂控制设定点之间相互作用的结果（涌现特性假说）以及抵御寄生入侵者（漫步节肢动物假说）。我们描述了用于在有或没有DGC的情况下测量呼吸水分流失以试图检验湿度假说的特定技术，如高氧转换和H₂O/CO₂回归，并总结了该领域可能是未来研究有益方向的特定领域。
