title: Interaction of mercury and selenium in the larval stage zebrafish vertebrate model.
abstract: The compounds of mercury can be more toxic than those of any other non-radioactive heavy element. Despite this, environmental mercury pollution and human exposure to mercury are widespread, and are increasing. While the unusual ability of selenium to cancel the toxicity of mercury compounds has been known for nearly five decades, only recently have some aspects of the molecular mechanisms begun to be understood. We report herein a study of the interaction of mercury and selenium in the larval stage zebrafish, a model vertebrate system, using X-ray fluorescence imaging. Exposure of larval zebrafish to inorganic mercury shows nano-scale structures containing co-localized mercury and selenium. No such co-localization is seen with methylmercury exposure under similar conditions. Micro X-ray absorption spectra support the hypothesis that the co-localized deposits are most likely comprised of highly insoluble mixed chalcogenide HgSxSe(1-x) where x is 0.4-0.9, probably with the cubic zincblende structure.
authors.affiliation: Molecular and Environmental Science Research Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada. g.george@usask.ca.
authors.forename: Tracy C
authors.initials: TC
authors.lastname: MacDonald
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Korbas
authors.forename: Ashley K
authors.initials: AK
authors.lastname: James
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Sylvain
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Hackett
authors.forename: Susan
authors.initials: S
authors.lastname: Nehzati
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Krone
authors.forename: Graham N
authors.initials: GN
authors.lastname: George
authors.forename: Ingrid J
authors.initials: IJ
authors.lastname: Pickering
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism*; D007814:Larva / Q000378:metabolism / Q000648:ultrastructure; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000032:analysis / Q000378:metabolism*; D008958:Models, Molecular; D061848:Optical Imaging; D012643:Selenium / Q000032:analysis / Q000378:metabolism*; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D008628:Mercury; D012643:Selenium