Tang Xiaolong, Wu Juan, Zhang Haoqi, Zhong Liye, Su Rui, Ma Ming, Wang Huihui, Ma Miaojun, Chen Qiang
Department of Animal and Biomedical Sciences, School of Life Science, Lanzhou University, No. 222 Tianshui South Road, Lanzhou, Gansu Province 730000, China.
Department of Animal and Biomedical Sciences, School of Life Science, Lanzhou University, No. 222 Tianshui South Road, Lanzhou, Gansu Province 730000, China; College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do 14662, Republic of Korea.
Ecotoxicol Environ Saf. 2025 Apr 1;294:118075. doi: 10.1016/j.ecoenv.2025.118075. Epub 2025 Mar 20.
Ultraviolet-B radiation (UVBR), intensified by ozone depletion and climate change, poses a growing ecological threat to amphibians, particularly in high-elevation regions such as the Qinghai-Tibet Plateau. Endemic to this region, Rana kukunoris spans a wide range of elevations, where distinct populations may have evolved unique strategies and regulatory mechanisms to cope with UVBR. However, specific adaptive responses in adult frogs remain underexplored. This study compared the physiological responses of high- and low-altitude Rana kukunoris populations to UVBR exposure, focusing on dorsal color, immune function, antioxidant capacity, and DNA repair gene expression. High-altitude populations exhibited stable, dark pigmentation-potentially reducing the need for rapid melanin synthesis-alongside a robust immune profile and enhanced antioxidant enzyme activity, collectively conferring resilience against oxidative and immune stress under chronic UVBR exposure. Conversely, low-altitude populations exhibited pronounced UVBR-induced responses, including significant skin darkening, heightened immune activation evidenced by increased white blood cell counts, and increased oxidative damage marked by higher malondialdehyde (MDA) levels, coupled with reduced superoxide dismutase (SOD) and catalase (CAT) activities. Furthermore, tissue-specific upregulation of DNA repair genes in high-altitude populations suggested a stable DNA repair capacity adapted to high-UVBR environments. These findings reveal distinct physiological strategies within the same species for coping with UVBR across altitudinal gradients. Amid global increases in UVBR, this study offers novel insights into amphibian resilience in high-UVBR habitats and informs conservation strategies for populations across varying elevations.
紫外线B辐射（UVBR）因臭氧损耗和气候变化而增强，对两栖动物构成了日益严重的生态威胁，尤其是在青藏高原等高海拔地区。高原林蛙是该地区的特有物种，分布在广泛的海拔范围内，不同种群可能已经进化出独特的应对UVBR的策略和调节机制。然而，成年青蛙的具体适应性反应仍未得到充分研究。本研究比较了高海拔和低海拔高原林蛙种群对UVBR暴露的生理反应，重点关注背部颜色、免疫功能、抗氧化能力和DNA修复基因表达。高海拔种群表现出稳定的深色素沉着——可能减少了快速合成黑色素的需求——同时具有强大的免疫特征和增强的抗氧化酶活性，共同赋予了在长期UVBR暴露下抵抗氧化和免疫应激的能力。相反，低海拔种群表现出明显的UVBR诱导反应，包括皮肤显著变黑、白细胞计数增加证明的免疫激活增强，以及丙二醛（MDA）水平升高标志的氧化损伤增加，同时超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性降低。此外，高海拔种群中DNA修复基因的组织特异性上调表明其具有适应高UVBR环境的稳定DNA修复能力。这些发现揭示了同一物种内不同的生理策略，用于应对不同海拔梯度下的UVBR。在全球UVBR增加的背景下，本研究为高UVBR栖息地中两栖动物的恢复力提供了新的见解，并为不同海拔种群的保护策略提供了参考。
