Department of Fisheries and Ocean Science, Chonnam National University, San 96-1, Dundeok-dong, Yeosu, Jeonnam 550-749, Republic of Korea.
Comp Biochem Physiol C Toxicol Pharmacol. 2010 May;151(4):439-46. doi: 10.1016/j.cbpc.2010.01.009. Epub 2010 Feb 4.
2,4-Dichlorophenoxyacetic acid (2,4-D) is an agricultural contaminant found in rural ground water. It remains to be determined whether neither 2,4-D poses environmental risks, nor is the mechanism of toxicity known at the molecular level. To evaluate the potential ecological risk of 2,4-D, we assessed the biological parameters including the survival rate, adult sex ratio of emerged adults, and mouthpart deformities in Chironomus riparius after long-term exposure to 2,4-D. The larvae were treated with 0.1, 1 or, 10microgL(-1) of 2,4-D for short- and long-term exposure periods. The sex ratio was changed in C. riparius exposed to only 10microgL(-1) of 2,4-D, whereas mouthpart deformities were observed as significantly higher in C. riparius exposed to 0.1microgL(-1) of 2,4-D. Survival rates were not significantly affected by 2,4-D. Furthermore, we evaluated the molecular and biochemical responses of biomarker genes such as gene expression of heat shock proteins (HSPs), ferritins and glutathione S-transferases (GSTs) in C. riparius exposed to 2,4-D for 24h. The expressions of HSP70, HSP40, HSP90 and GST levels in C. riparius were significantly increased after exposure to a 10microgL(-1) concentration of 2,4-D, whereas ferritin heavy and light chain gene expressions were significantly increased at all concentrations of 2,4-D exposure. Finally, these results may provide an important contribution to our understanding of the toxicology of 2,4-D herbicide in C. riparius. Moreover, the 2,4-D-mediated gene expressions may be generated by 2,4-D is the causative effects on most probable cause of the observed alterations. These biological, molecular and morphological parameters and the measured parameters can be used to monitor 2,4-D toxicity in an aquatic environment.
2,4-二氯苯氧乙酸（2,4-D）是一种在农村地下水环境中发现的农业污染物。目前尚不清楚 2,4-D 是否存在环境风险，也不清楚其毒性的分子机制。为了评估 2,4-D 的潜在生态风险，我们评估了包括存活率、成虫雌雄比和口器畸形在内的生物学参数，这些参数是在 2,4-D 长期暴露后在摇蚊幼虫中观察到的。幼虫用 0.1、1 或 10μg/L 的 2,4-D 进行短期和长期暴露处理。仅暴露于 10μg/L 的 2,4-D 会改变摇蚊的性别比例，而暴露于 0.1μg/L 的 2,4-D 会导致口器畸形显著增加。2,4-D 对存活率没有显著影响。此外，我们评估了 2,4-D 暴露 24 小时后生物标志物基因如热休克蛋白（HSPs）、铁蛋白和谷胱甘肽 S-转移酶（GSTs）的基因表达的分子和生化反应。暴露于 10μg/L 的 2,4-D 后，摇蚊的 HSP70、HSP40、HSP90 和 GST 水平的表达显著增加，而铁蛋白重链和轻链基因的表达在所有 2,4-D 暴露浓度下均显著增加。最后，这些结果可能为我们理解 2,4-D 除草剂对摇蚊的毒理学提供重要贡献。此外，2,4-D 介导的基因表达可能是由 2,4-D 是引起观察到的变化的最可能原因造成的。这些生物学、分子和形态学参数以及测量参数可用于监测水生环境中的 2,4-D 毒性。
