Transcriptional Responses of Stress-Related Genes in Pale Chub (Zacco platypus) Inhabiting Different Aquatic Environments: Application for Biomonitoring Aquatic Ecosystems

Abstract

Pale chub (Zacco platypus) is a dominant species in urban rivers and reservoirs, and it is used as an indicator to monitor the effects of environmental contaminants. Gene responses at the molecular level can reflect the health of fish challenged with environmental stressors. The objective of this study was to identify correlations between water quality factors and the expression of stress-related genes in Z. platypus from different lake environments (Singal and Juam Lakes). To do so, transcriptional responses of genes involving cellular homeostasis (heat-shock protein 70, HSP70; heat-shock protein 90, HSP90), metal detoxification (metallothionein, MT), and antioxidation (superoxide dismutase, SOD; catalase, CAT) were analyzed in the gill and liver tissues of Z. platypus. HSP70, HSP90, and MT genes were overall upregulated in Z. platypus from Singal Lake, which suffered from poorer water quality than Juam Lake. In addition, gene responses were significantly higher in Singal Lake outflow. Upregulation of HSP70, HSP90, and MT was significantly higher in Z. platypus gills than in the liver tissue. In addition, integrated biomarker response and heatmap analysis determined correlations between expression of biomarker genes or water quality factors and sampling sites of both lakes. These results suggest that stress-related genes used as multiple biomarkers may reflect spatial characteristics and water quality of different lake environments, and they can be used for biomonitoring and ecological risk assessment.

Proposing Effective Ecotoxicity Test Species for Chemical Safety Assessment in East Asia: A Review

“…They have shown the potential as a promising test species in a sub-organism/organism level. Precisely by exposure of benzo( a )pyrene, cadmium, copper, wastewater contaminated with municipal chemicals (Cd, Co, Cr, Mn, Ni), Z. platypus showed oxidative stress occurrence (increase of MDA content, CAT and SOD activity), enhanced biotransformation (CYP1A and CPR activation), genetic toxicity (DNA adduct formation, nuclear abnormality), stress responses (metallothionine expression, heat-shock protein 79/90), endocrine disruption (E2 hormone level, GSI), neurotoxicity (AChE activty) [ 71 , 72 , 73 , 74 , 76 , 77 , 78 , 79 , 80 , 81 ]. In addition, Ammonia treatment caused decrease of a survival rate and a hatching rate as well as deformed alevins increase [ 75 ].…”

Advancements in Biomonitoring and Remediation Treatments of Pollutants in Aquatic Environments, 2nd Edition

“…Morphological and biochemical-based approaches are now supported using transcriptomic analysis and metabolomic studies, allowing us to identify the exact genetic or metabolic function altered by the pollutants. The appearance of genetic damages prolongs the negative impact of pollutants even after their removal [22,[28][29][30][31][32].…”