Ammonia is a major pollutant in the water environment, which could cause severe harm to aquatic organisms. To explore the pathological and physiological effects of ammonia in Chinese striped-necked turtles (Mauremys sinensis), the individuals (body mass: 218.26 ± 12.65 g) were divided into two groups: control group and ammonia exposed group (6.25 mM total ammonia), then the expression levels of signaling factors involved in the endoplasmic reticulum stress and apoptotic pathways were determined. The results showed that ammonia exposure up-regulated the transcriptional and protein levels of endoplasmic reticulum stress marker gene Bip. Meanwhile, the relative mRNA levels of key genes (PERK, ATF6, eIF2α, ATF4, IRE1α and XBP1) involved in unfolded protein response up-regulated, and the phosphorylation levels of PERK, eIF2α and IRE1α increased correspondingly. In addition, the protein and transcriptional levels of CHOP and JNK related to apoptotic pathway induced by unfolded protein reaction increased under ammonia exposure. Moreover, Bcl-2 mRNA expression levels and protein levels decreased, whereas BAX and caspase-3 showed an opposite trend, and the cleaved protein of caspase-3 appeared when the turtles in the elevated ammonia. Furthermore, the apoptotic cells in liver increased after ammonia exposure. These results suggested ammonia exposure induced endoplasmic reticulum stress, then activated unfolded protein response, followed by apoptosis in M. sinensis. The results will contribute to a better understanding of the toxicity mechanism of ammonia to aquatic turtles.

氨是水环境中的主要污染物，会对水生生物造成严重危害。探讨氨对中华斑鳖（Mauremys sinensis）的病理生理影响)，将个体(体重：218.26±12.65 g)分为对照组和氨暴露组(总氨6.25 mM)，然后测定参与内质网应激和凋亡途径的信号因子的表达水平. 结果表明，氨暴露上调了内质网应激标记基因 Bip 的转录和蛋白质水平。同时，参与未折叠蛋白反应的关键基因（PERK、ATF6、eIF2α、ATF4、IRE1α和XBP1）的相对mRNA水平上调，PERK、eIF2α和IRE1α的磷酸化水平相应增加。此外，与未折叠蛋白反应诱导的凋亡途径相关的CHOP和JNK的蛋白质和转录水平在氨暴露下增加。此外，Bcl-2 mRNA表达水平和蛋白水平下降，而BAX和caspase-3呈相反趋势，当龟在氨升高时出现caspase-3裂解蛋白。此外，氨暴露后肝脏中的凋亡细胞增加。这些结果表明氨暴露诱导内质网应激，然后激活未折叠蛋白反应，随后细胞凋亡中华木耳。结果将有助于更好地了解氨对水龟的毒性机制。