Specific Effects of Dietary Methylmercury and Inorganic Mercury in Zebrafish (Danio rerio) Determined by Genetic, Histological, and Metallothionein Responses.
A multidisciplinary approach is proposed here to compare toxicity mechanisms of methylmercury (MeHg) and inorganic mercury (iHg) in muscle, liver, and brain from zebrafish (Danio rerio). Animals were dietary exposed to (1) 50 ng Hg g(-1), 80% as MeHg; (2) diet enriched in MeHg 10000 ng Hg g(-1), 95% as MeHg; (3) diet enriched in iHg 10000 ng Hg g(-1), 99% as iHg, for two months. Hg species specific bioaccumulation pathways were highlighted, with a preferential bioaccumulation of MeHg in brain and iHg in liver. In the same way, differences in genetic pattern were observed for both Hg species, (an early genetic response (7 days) for both species in the three organs and a late genetic response (62 days) for iHg) and revealed a dissimilar metabolization of both Hg species. Among the 18 studied genes involved in key metabolic pathways of the cell, major genetic responses were observed in muscle. Electron microscopy revealed damage mainly because of MeHg in muscle and also in liver tissue. In brain, high MeHg and iHg concentrations induced metallothionein production. Finally, the importance of the fish origin in ecotoxicological studies, here the seventh descent of a zebrafish line, is discussed.
Université de Bordeaux, EPOC, UMR CNRS 5805 , Place du Dr B. Peyneau, F-33120 Arcachon, France.
Sophie
S
Gentès
Université de Bordeaux, EPOC, UMR CNRS 5805 , Place du Dr B. Peyneau, F-33120 Arcachon, France.
Régine
R
Maury-Brachet
Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, F-64053 Pau, France.
Caiyan
C
Feng
Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, F-64053 Pau, France.
Zoyne
Z
Pedrero
Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, F-64053 Pau, France.
Emmanuel
E
Tessier
Université de Bordeaux, EPOC, UMR CNRS 5805 , Place du Dr B. Peyneau, F-33120 Arcachon, France.
Alexia
A
Legeay
Université de Bordeaux, EPOC, UMR CNRS 5805 , Place du Dr B. Peyneau, F-33120 Arcachon, France.
Nathalie
N
Mesmer-Dudons
Université de Bordeaux, EPOC, UMR CNRS 5805 , Place du Dr B. Peyneau, F-33120 Arcachon, France.
Magalie
M
Baudrimont
Observatoire Midi-Pyrénées, Laboratoire de Geosciences Environnement Toulouse, Université Paul Sabatier Toulouse III , 14 avenue Edouard Belin, 31400 Toulouse, France.|GET, IRD , F-31400 Toulouse, France.
Laurence
L
Maurice
Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, F-64053 Pau, France.
David
D
Amouroux
CNRS, EPOC, UMR 5805, F-33120 Arcachon, France.
Patrice
P
Gonzalez
D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D054750:Ecotoxicology / Q000379:methods; D004781:Environmental Exposure / Q000009:adverse effects; D005786:Gene Expression Regulation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008628:Mercury / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity*; D008668:Metallothionein / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000493:pharmacokinetics / Q000633:toxicity*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*
D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D008628:Mercury