College of Life Science, Shaanxi Normal University, Xi'an, 710119, China.
Basic Experimental Teaching Center, Shaanxi Normal University, Xi'an, 710119, China.
Environ Pollut. 2023 Oct 15;335:122333. doi: 10.1016/j.envpol.2023.122333. Epub 2023 Aug 7.
Endocrine disruptors have been demonstrated to exert adverse effects on growth and development of amphibians by disrupting hormone levels. Tail resorption, which is one of the most remarkable events during amphibian metamorphosis, is closely associated with thyroid hormones levels. However, limited research has been conducted on the effects of endocrine disruptors on tail resorption in amphibians. This study explored the effects of NaClO and T4 on the growth, development and tail resorption during the metamorphosis of Rana Chensinensis. The results demonstrated that exposure to NaClO led to an increase in body size and a delay in metamorphosis of R. Chensinensis tadpoles. Histological analysis revealed that both NaClO and exogenous T4 exposure resulted in thyroid gland injury, and NaClO treatment delayed the degradation of notochord and muscles, thereby delaying tail resorption. Moreover, transcriptome sequencing results showed that apoptosis-related genes (APAF1, BAX and CASP6) and cell component degradation-related genes (MMP9 and MMP13) were highly expressed in the T4 exposure group, and the expression of oxidative stress-related genes (SOD and CAT) was higher in the NaClO exposure group. Taken together, both NaClO and exogenous T4 affect tail resorption in R. Chensinensis, thereby affecting their adaptation to terrestrial life. The present study will not only provide a reference for future experimental research on the effects of other endocrine disruptors on the growth, development and tail resorption of amphibians but will also provide insights into environmental protection and ecological risk assessment.
内分泌干扰物已被证明通过干扰激素水平对两栖动物的生长和发育产生不良影响。尾巴吸收是两栖动物变态过程中最显著的事件之一，与甲状腺激素水平密切相关。然而，关于内分泌干扰物对两栖动物尾巴吸收的影响的研究有限。本研究探讨了次氯酸钠（NaClO）和 T4 对中华蟾蜍（Rana Chensinensis）变态过程中生长、发育和尾巴吸收的影响。结果表明，暴露于次氯酸钠（NaClO）会导致中华蟾蜍（R. Chensinensis）蝌蚪的体型增大和变态延迟。组织学分析表明，NaClO 和外源性 T4 暴露均导致甲状腺损伤，NaClO 处理延迟了脊索和肌肉的降解，从而延迟了尾巴吸收。此外，转录组测序结果表明，凋亡相关基因（APAF1、BAX 和 CASP6）和细胞成分降解相关基因（MMP9 和 MMP13）在 T4 暴露组中高度表达，而氧化应激相关基因（SOD 和 CAT）在 NaClO 暴露组中的表达更高。综上所述，NaClO 和外源性 T4 均影响中华蟾蜍的尾巴吸收，从而影响它们对陆地生活的适应。本研究不仅为未来关于其他内分泌干扰物对两栖动物生长、发育和尾巴吸收影响的实验研究提供参考，也为环境保护和生态风险评估提供了思路。
