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造成不利影响，包括改变基因表达。因此，本研究调查了栖息在甜菜工厂（受工业污染的栖息地）和尼罗河（参考栖息地）的排水渠中的尼罗罗非鱼中暴露和影响生物标志物的肝脏表达。与尼罗河相比，排水渠的重金属（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的含量显着升高。来自引流管的尼罗罗非鱼肝脏积累了显着更高浓度的重金属。尼罗罗非鱼从排水渠有与氧化应激（基因显著更高肝表达式GSTA，GPx的，和NRF2），金属毒性（MT），内分泌紊乱（Vtg的），和缺氧（HIF1A）和细胞凋亡的显著降低肝表达-相关的CAS基因。CYP1A（一种解毒生物标志物）表达没有表现出显着差异。这些结果提供了对O. niloticus对多种化学物质的复杂适应性反应的见解，并支持利用分子生物标志物作为水污染的警告信号。