Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China.
Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China.
Chemosphere. 2021 Oct;280:130630. doi: 10.1016/j.chemosphere.2021.130630. Epub 2021 Apr 22.
Ammonia is an important environmental pollutant and can induce serious damages to the organs of aquatic animals, especially the intestine which is mostly exposed to external environment. As important species of aquatic ecosystems, turtles may be potential risk targets of ammonia. However, it is not clear whether ammonia shows toxic effects on the intestines of turtles. Therefore, the worldwide species red-eared slider (Trachemys scripta elegans) was selected, to investigate the effects of ammonia on intestinal health and the composition of microbiota. Results showed that ammonia significantly changed the structure of intestines by decreasing the thickness of intestinal wall, shortening the length of intestinal villus, extending lamina proprias, and inducing inflammatory cells appearance when the turtles were exposed to ammonia (1.418 mg NH L) for 30 d. In addition, the downregulation of epithelial tight junction genes indicated that ammonia increased selective paracellular permeability. Simultaneously, the upregulation of cytokines suggested that ammonia induced intestinal immune and inflammatory responses. Furthermore, ammonia altered the dominant bacterial composition, and decreased the abundance of beneficial intestinal bacteria in the host. Our results demonstrated that ammonia impaired the intestinal health and changed the composition of residential microbiota in T. s. elegans. This study provides a new insight to evaluate the toxic effects of ammonia on aquatic turtles and helps to build a framework for the effective conservation of turtles.
氨是一种重要的环境污染物，可对水生动物的器官造成严重损害，尤其是肠道，因为肠道大部分暴露于外部环境中。作为水生生态系统的重要物种，龟类可能是氨的潜在风险目标。然而，氨是否对龟类的肠道产生毒性作用尚不清楚。因此，本研究选择了世界范围内分布的红耳滑龟（Trachemys scripta elegans），以研究氨对肠道健康和微生物群落组成的影响。结果表明，当龟类暴露于氨（1.418 mg NH L）30 d 时，氨通过降低肠壁厚度、缩短肠绒毛长度、延伸固有层，以及诱导炎症细胞出现，显著改变了肠道结构。此外，上皮紧密连接基因的下调表明氨增加了选择性细胞旁通透性。同时，细胞因子的上调表明氨诱导了肠道免疫和炎症反应。此外，氨改变了主要细菌组成，降低了宿主中有益肠道细菌的丰度。我们的研究结果表明，氨损害了 T. s. elegans 的肠道健康，并改变了其居住微生物群落的组成。本研究为评估氨对水生龟类的毒性作用提供了新的视角，并有助于为龟类的有效保护建立框架。
