Bioaccumulation and molecular effects of sediment-bound metals in zebrafish embryos.
Predicting the bioavailability and effects of metals in sediments is of major concern in context with sediment risk assessment. This study aimed to investigate the bioavailability and molecular effects of metals spiked into riverine sediments to zebrafish (Danio rerio) embryos. Embryos were exposed to a natural and an artificial sediment spiked with cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) individually or as a mixture at concentrations ranging from 150 to 3000 mg/kg dry weight (dw) over 48 h, and uptake of metals was determined. Furthermore, transcript abundances of the metallothioneins MT1 and MT2, the metal-responsive element-binding transcription factor (MTF) and the genes sod1, hsp70 and hsp90α1 were measured as indicators of metal-induced or general cellular stress. D. rerio embryos accumulated metals from sediments at concentrations up to 100 times greater than those spiked to the sediment with the greatest bioaccumulation factor (BAF) for Cu from artificial sediment (275.4 ± 41.9 (SD)). Embryos accumulated greater concentrations of all metals from artificial than from natural sediment, and accumulation was greater when embryos were exposed to individual metals than when they were exposed to the mixture. Exposure of embryos to Zn or the mixture exhibited up to 30-fold greater transcript abundances of MT1, MT2 and hsp70 compared to controls which is related to significant uptake of Zn from the sediment. Further changes in transcript abundances could not be related to a significant uptake of metals from sediments. These studies reveal that metals from spiked sediments are bioavailable to D. rerio embryos directly exposed to sediments and that the induction of specific genes can be used as biomarkers for the exposure of early life stages of zebrafish to metal-contaminated sediments.
Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
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Redelstein
Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
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Zielke
German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068, Koblenz, Germany.
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Spira
German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068, Koblenz, Germany.
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U
Feiler
Department of Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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Erdinger
Department of Internal Medicine and Clinical Chemistry I, University Hospital Heidelberg, Im Neuenheimer Feld 671, 69120, Heidelberg, Germany.
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Zimmer
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
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Wiseman
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.|School of the Environment & Sustainability, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
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M
Hecker
Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.|Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada.|Department of Zoology, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, 48895, USA.|Department of Biology & Chemistry, City University of Hong Kong, Kowloon, Hong Kong, SAR, People's Republic of China.
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Giesy
Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
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Seiler
Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany. henner.hollert@bio5.rwth-aachen.de.|Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai, 200092, People's Republic of China. henner.hollert@bio5.rwth-aachen.de.|College of Resources and Environmental Science, Chongqing University, Chongqing, 400030, People's Republic of China. henner.hollert@bio5.rwth-aachen.de.|State Key Laboratory of Pollution Control and Research Reuse, School of the Environment, Nanjing University, Nanjing, 210093, People's Republic of China. henner.hollert@bio5.rwth-aachen.de.
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Hollert
D000818:Animals; D002104:Cadmium / Q000493:pharmacokinetics / Q000633:toxicity; D003300:Copper / Q000493:pharmacokinetics / Q000633:toxicity; D015870:Gene Expression / Q000187:drug effects; D019015:Geologic Sediments / Q000737:chemistry; D009532:Nickel / Q000493:pharmacokinetics / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000633:toxicity; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism; D015032:Zinc / Q000493:pharmacokinetics / Q000633:toxicity
D014874:Water Pollutants, Chemical; D029961:Zebrafish Proteins; D002104:Cadmium; D003300:Copper; D009532:Nickel; D015032:Zinc
Bioaccumulation; Bioavailability; Metallothioneins; Metals; Sediment risk assessment; Zebrafish