Liang Liang, Sun Bao-Jun, Ma Liang, Du Wei-Guo
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
J Comp Physiol B. 2015 Feb;185(2):257-63. doi: 10.1007/s00360-014-0874-4. Epub 2014 Dec 19.
Oxygen and temperature have previously been treated as different environmental stresses and studied separately in most cases. Although the oxygen-temperature interaction may provide new insight into proximate and evolutionary constraints on embryonic development and offspring fitness, it has rarely been studied in oviparous amniotes. We used a two-factor experiment [three oxygen concentrations (12, 22 and 30%) × two temperatures (26.5 and 34 °C)] to identify the effect of the oxygen-temperature interaction on embryonic development and hatchling traits in the Chinese soft-shelled turtle, Pelodiscus sinensis. When eggs were incubated at the critically high temperature, hatching success of turtle eggs was enhanced by hyperoxia but reduced by hypoxia; this result was not observed in eggs incubated at the benign temperature. Hypoxia retarded embryonic development, and reduced body size, locomotor performance and survival rate of hatchings at the critically high temperature. However, the effects of hypoxia were greatly reduced at the benign temperature. Our study demonstrates that oxygen and temperature interact to affect not only the heat tolerance and developmental rate of embryos but also the fitness-related traits of hatchlings, suggesting that interactions among environmental factors impose significant ecological constraints on embryonic development in oviparous amniotes.
以往，氧气和温度被视为不同的环境压力因素，且在大多数情况下是分别进行研究的。尽管氧 - 温度相互作用可能为胚胎发育和后代适应性的近端及进化限制提供新的见解，但在卵生羊膜动物中却很少被研究。我们采用了双因素实验[三种氧气浓度（12%、22%和30%）×两种温度（26.5℃和34℃）]来确定氧 - 温度相互作用对中华鳖（Pelodiscus sinensis）胚胎发育和幼体特征的影响。当卵在临界高温下孵化时，高氧可提高鳖卵的孵化成功率，而低氧则会降低孵化成功率；在适宜温度下孵化的卵未观察到这一结果。低氧会延缓胚胎发育，并降低临界高温下幼体的体型、运动能力和存活率。然而，在适宜温度下，低氧的影响会大大降低。我们的研究表明，氧气和温度相互作用不仅会影响胚胎的耐热性和发育速率，还会影响幼体与适应性相关的特征，这表明环境因素之间的相互作用对卵生羊膜动物的胚胎发育施加了重大的生态限制。
