Cu accumulation, detoxification and tolerance in the red swamp crayfish Procambarus clarkii

• Published in: Ecotoxicology and environmental safety 2019-07, Vol.175, p.201-207
• Main Authors: Dan Zhao, Zhang, Xiaona, Liu, Dasheng, Ru, Shaoguo
• Format: Article
• Language: English
• Subjects: Antioxidative system; Copper; Cu detoxification; Cu homeostasis; Procambarus clarkii
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.03.031

Copper is an essential metal but potentially toxic to aquatic animals at high levels. The present study investigated physiologically adaptive responses to waterborne Cu2+ exposure (0, 0.03, 0.30, 3.00 mg/L) in a representative species of crustaceans, the red swamp crayfish (Procambarus clarkii) for 7 d, followed by a 7-d depuration period. The tissue-specific distribution of Cu showed that crayfish hepatopancreas was the primary accumulating site among internal tissues. During Cu2+ exposure, crayfish repressed the expression level of Cu homeostasis genes (Ctr1, Atox1, copper-transporting ATPase 2, MTF-1/2, and MT) in hepatopancreas to inhibit intracellular Cu transporting. Cu2+-exposed crayfish increased activities of GPx and GST, GSH contents, and mRNA expression of antioxidative enzyme genes (Cu/Zn-sod, cat, gpx, gst) to cope with the Cu2+-induced oxidative stress which accompanied by an increased MDA content. Additionally, after a 7-d depuration, crayfish effectively eliminated excess Cu from hepatopancreas by up-regulating expression level of Cu homeostasis genes, and recovered from oxidative damage by enhancing antioxidative enzyme gene expression (Cu/Zn-sod, cat, gpx, gst) and consuming more GSH, which thereby caused a return of the MDA level to the control value. Overall, our study provided new insights into the regulatory mechanisms of cellular Cu homeostasis system and antioxidative system, contributing to Cu detoxification and tolerance ability exhibited by crayfish under Cu2+ stress and after withdrawal of Cu2+ stress. •Crayfish hepatopancreas was the primary accumulating site among internal tissues.•Excessive Cu was completely eliminated from hepatopancreas after a 7-d depuration.•Crayfish regulated Cu homeostasis system to detoxify Cu during exposure and depuration.•Crayfish activated antioxidant system to tolerate and recover from oxidative stress.