Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Ecotoxicol Environ Saf. 2022 Oct 1;244:114040. doi: 10.1016/j.ecoenv.2022.114040. Epub 2022 Aug 30.
The non-breeding season is a critical period for iteroparous animals to repair damage and store energy, which is crucial for future survival and reproductive success. However, it is unknown how animals allocate energy efficiently among reproduction, self-maintenance, and repair of oxidative damage caused by breeding during the non-breeding period, particularly under pollution. In the present study, the self-maintenance response and reproductive strategy of Bufo raddei to long-term environmental heavy metal stress was explored during the non-breeding season. Heavy metal enrichment level, organ coefficients, nutritional status, gonadal developmental level, oxidation level, and the immune status of B. raddei during the non-breeding season were tested, energy allocation preferences and energy consumption costs were analyzed. The results revealed significant heavy metal accumulation through biomagnification in the organs of B. raddei from the polluted area. Under long-term environmental heavy metal pollution, the energy investment by B. raddei for growth and energy storage was higher than that for health-maintenance during the early life cycle stage. The energy inputted for immune and antioxidant functions was significantly lower, and the energy inputted for self-maintenance during the early life stage was significantly higher than that during the late stage. B. raddei from a heavy metal polluted area spent more energy consumption cost on immunity and oxidative stress, but suffered higher oxidative stress and lower immune status. Moreover, the reproductive input of individuals in a heavy metal polluted area was generally low during the non-breeding season, and the energy input for reproduction limited the energy input for self-maintenance in females.
非繁殖季节是复壮动物修复损伤和储存能量的关键时期，这对未来的生存和繁殖成功至关重要。然而，目前尚不清楚动物在非繁殖期如何在繁殖、自我维持和修复繁殖引起的氧化损伤之间有效地分配能量，特别是在受到污染的情况下。本研究探讨了非繁殖季节中中华蟾蜍对长期环境重金属胁迫的自我维持反应和繁殖策略。检测了非繁殖季节中华蟾蜍的重金属富集水平、器官系数、营养状况、性腺发育水平、氧化水平和免疫状况，分析了能量分配偏好和能量消耗成本。结果表明，受污染地区中华蟾蜍的器官中存在明显的重金属生物放大现象。在长期的环境重金属污染下，中华蟾蜍在生命早期阶段用于生长和能量储存的能量投入高于用于健康维持的能量投入。用于免疫和抗氧化功能的能量投入显著降低，生命早期的自我维持能量投入显著高于生命晚期。来自重金属污染地区的中华蟾蜍在免疫和氧化应激方面消耗更多的能量成本，但遭受更高的氧化应激和更低的免疫状态。此外，重金属污染地区个体在非繁殖季节的生殖投入普遍较低，生殖投入限制了雌性的自我维持能量投入。
