Department of Entomology and Department of Evolution, Ecology and Organismal Biology, Ohio State University, Columbus, OH 43210, USA.
J Exp Biol. 2014 Jan 1;217(Pt 1):84-93. doi: 10.1242/jeb.089490.
Abiotic stress is one of the primary constraints limiting the range and success of arthropods, and nowhere is this more apparent than Antarctica. Antarctic arthropods have evolved a suite of adaptations to cope with extremes in temperature and water availability. Here, we review the current state of knowledge regarding the environmental physiology of terrestrial arthropods in Antarctica. To survive low temperatures, mites and Collembola are freeze-intolerant and rely on deep supercooling, in some cases supercooling below -30°C. Also, some of these microarthropods are capable of cryoprotective dehydration to extend their supercooling capacity and reduce the risk of freezing. In contrast, the two best-studied Antarctic insects, the midges Belgica antarctica and Eretmoptera murphyi, are freeze-tolerant year-round and rely on both seasonal and rapid cold-hardening to cope with decreases in temperature. A common theme among Antarctic arthropods is extreme tolerance of dehydration; some accomplish this by cuticular mechanisms to minimize water loss across their cuticle, while a majority have highly permeable cuticles but tolerate upwards of 50-70% loss of body water. Molecular studies of Antarctic arthropod stress physiology are still in their infancy, but several recent studies are beginning to shed light on the underlying mechanisms that govern extreme stress tolerance. Some common themes that are emerging include the importance of cuticular and cytoskeletal rearrangements, heat shock proteins, metabolic restructuring and cell recycling pathways as key mediators of cold and water stress in the Antarctic.
非生物胁迫是限制节肢动物分布和成功的主要限制因素之一，而在南极洲，这种情况更为明显。南极节肢动物已经进化出了一系列适应极端温度和水分供应的适应能力。在这里，我们综述了目前关于南极洲陆地节肢动物环境生理学的知识状况。为了在低温下生存，螨和弹尾目昆虫是不耐冻的，它们依赖于深度过冷却，在某些情况下，过冷却温度低于-30°C。此外，一些这些微节肢动物能够进行抗冷冻脱水，以延长其过冷却能力并降低冻结的风险。相比之下，研究最充分的两种南极昆虫，即拟蠓 Belgica antarctica 和 Eretmoptera murphyi，全年都具有耐冻性，它们依靠季节性和快速的冷驯化来应对温度下降。南极节肢动物的一个共同主题是对脱水的极端耐受；有些通过角质层机制来实现，以最大限度地减少其角质层上的水分流失，而大多数具有高度可渗透的角质层，但可以耐受高达 50-70%的身体水分损失。对南极节肢动物应激生理学的分子研究仍处于起步阶段，但最近的几项研究开始揭示控制极端应激耐受的潜在机制。一些正在出现的共同主题包括角质层和细胞骨架重排、热休克蛋白、代谢重构和细胞回收途径作为南极地区冷和水应激的关键介质的重要性。
