Zoology Department, Faculty of Sciences, Mansoura University, 35516, Mansoura, Egypt.
Bull Environ Contam Toxicol. 2021 Nov;107(5):889-894. doi: 10.1007/s00128-021-03341-1. Epub 2021 Aug 9.
Chemical pollution poses adverse effects on aquatic organisms, including altered gene expression. This study, therefore, investigated the hepatic expression of biomarkers of exposure and effect in Oreochromis niloticus inhabiting the drainage canal of a sugarbeet factory (an industrially polluted habitat) and the Nile River (a reference habitat). Compared to the Nile River, the drainage canal contained significantly elevated levels of heavy metals (Cd, Fe, Mn, Co, and Pb), nitrate, ammonia, nitrite, chemical oxygen demand, and biological oxygen demand. The liver of O. niloticus from the drainage canal accumulated significantly higher concentrations of the heavy metals. O. niloticus from the drainage canal had significantly higher hepatic expressions of genes related to oxidative stress (GSTa, GPx, and NRF2), metal toxicity (MT), endocrine disruption (Vtg), and hypoxia (HIF1a) and a significantly lower hepatic expression of the apoptosis-associated CAS gene. CYP1A (a detoxification biomarker) expression did not exhibit significant differences. These results provide insights into complex adaptive responses of O. niloticus to multiple chemicals and support the utilization of molecular biomarkers as warning signals for water pollution.
化学污染对水生生物产生不良影响，包括改变基因表达。因此，本研究调查了栖息在甜菜厂排水渠（工业污染生境）和尼罗河（参考生境）中的尼罗罗非鱼的暴露和效应生物标志物的肝表达。与尼罗河相比，排水渠中含有显著更高水平的重金属（Cd、Fe、Mn、Co 和 Pb）、硝酸盐、氨、亚硝酸盐、化学需氧量和生物需氧量。来自排水渠的奥尼罗非鱼肝脏中积累了显著更高浓度的重金属。来自排水渠的奥尼罗非鱼的肝脏中与氧化应激（GSTa、GPx 和 NRF2）、金属毒性（MT）、内分泌干扰（Vtg）和缺氧（HIF1a）相关的基因表达显著升高，而与细胞凋亡相关的 CAS 基因的肝表达显著降低。CYP1A（解毒生物标志物）的表达没有表现出显著差异。这些结果深入了解了奥尼罗非鱼对多种化学物质的复杂适应反应，并支持将分子生物标志物用作水污染的预警信号。
