Chloroxylenol (para‑chloro-meta-xylenol, PCMX), is a widely used antimicrobial agent and can remain in the aquatic environment. Although toxicity studies related to PCMX on the aquatic animals like zebrafish and Brachionus koreanus have been reported, there are few reports in the ecological risk of amphibians. In this study, the toxicity of different concentration (143, 14.3, 1.43 μg/L) of PCMX treatments on the endochondral ossification and body condition of Rana chensiensis tadpoles was investigated at environmentally relevant concentrations during metamorphosis. The chronic exposure of PCMX decreased bone length and ossification of limbs, caused changes of thyroid gland structure and ossification related gene expression levels. Besides, we found that R. chensiensis developed rheumatoid arthritis. Therefore, these results provided valuable evidence that the ecological risk of PCMX that will negatively affect the body condition, thyroid hormones homeostasis and skeletal development of R. chensiensis tadpoles.

中文翻译：

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氯二甲酚暴露对 Rana chensinensis 的慢性毒性影响：来自软骨内骨化的见解


氯二甲酚（对氯间二甲酚，PCMX）是一种广泛使用的抗菌剂，可以残留在水生环境中。尽管已经报道了与 PCMX 相关的对斑马鱼和大韩腕鱼等水生动物的毒性研究，但关于两栖动物生态风险的报道很少。本研究以环境相关浓度 （143、14.3、1.43 μg/L） 的 PCMX 处理对陈氏蝌蚪过程中软骨内骨化和体况的毒性。PCMX 的长期暴露导致骨长度减少和四肢骨化，引起甲状腺结构和骨化相关基因表达水平的变化。此外，我们发现 R. chensiensis 发展为类风湿性关节炎。因此，这些结果提供了有价值的证据，证明 PCMX 的生态风险会对陈氏蝌蚪的身体状况、甲状腺激素稳态和骨骼发育产生负面影响。