Li Xinghan, Wu Pengfei, Ma Liang, Huebner Christopher, Sun Baojun, Li Shuran
College of Life and Environmental Science, Wenzhou University, Wenzhou, China.
Key Laboratory of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Institute of Zoology, Beijing, China.
Integr Zool. 2020 Jul;15(4):338-348. doi: 10.1111/1749-4877.12441. Epub 2020 May 25.
Low-elevation species can migrate toward higher elevations to survive in a warming world. However, animals' responses to hypoxia when migrating to high elevations have rarely been addressed. To identify the response of low-elevation lizards to high-elevation hypoxia, we collected field body temperatures (T ) and operative temperatures (T ) of lizards (Eremias argus) from a low-elevation population (1036 m) and a high-elevation population (2036 m), and then determined adult thermal physiology, embryonic development, and hatchling phenotypes after acclimating low-elevation lizards and incubating their eggs in conditions mimicking the low-elevation oxygen condition (18.5% O ) and high-elevation oxygen (hypoxic) condition (16.5% O ). Our study revealed that T and T were higher for the low-elevation population compared to the high-elevation population. We also found adults from low elevation acclimated to hypoxia preferred lower body temperatures, but did not show changes in locomotor performance or growth. In addition, hypoxia did not affect embryonic development (hatching time and success) or hatchling phenotypes (body size and locomotor performance). These results suggest that adult lizards from low elevations can respond to hypoxia-induced stress when migrating to high elevations by behaviorally thermoregulating to lower body temperatures in order to sustain normal functions. Similarly, low-elevation embryos can develop normally (with unchanged hatching success and offspring phenotypes) under the high-elevation hypoxic condition. This study highlights that low-elevation populations of a species that inhabits a range of elevations can buffer the impact of high-elevation hypoxic conditions to some degree and thus attain similar fitness to the source population.
低海拔物种可以向高海拔地区迁移，以便在气候变暖的世界中生存。然而，动物在迁移到高海拔地区时对缺氧的反应却很少得到研究。为了确定低海拔蜥蜴对高海拔缺氧的反应，我们收集了来自低海拔种群（1036米）和高海拔种群（2036米）的蜥蜴（丽斑麻蜥）的野外体温（T）和有效温度（T），然后在模拟低海拔氧气条件（18.5% O）和高海拔氧气（缺氧）条件（16.5% O）下，对低海拔蜥蜴进行驯化并孵化它们的卵，之后测定成年蜥蜴的热生理学、胚胎发育和幼体表型。我们的研究表明，低海拔种群的T和T高于高海拔种群。我们还发现，适应缺氧环境的低海拔成年蜥蜴更喜欢较低的体温，但运动表现或生长没有变化。此外，缺氧并不影响胚胎发育（孵化时间和成功率）或幼体表型（体型和运动表现）。这些结果表明，低海拔成年蜥蜴在迁移到高海拔地区时，可以通过行为性体温调节来降低体温，以应对缺氧诱导的压力，从而维持正常功能。同样，低海拔胚胎在高海拔缺氧条件下也能正常发育（孵化成功率和后代表型不变）。这项研究强调，一个栖息在不同海拔范围内的物种的低海拔种群可以在一定程度上缓冲高海拔缺氧条件的影响，从而获得与源种群相似的适合度。
