title: Decreased accumulation of cadmium in Drosophila selected for resistance suggests a mechanism independent of metallothionein.
abstract: Heavy metals, including cadmium, are common contaminants in environments subject to human activity. Responses to exposure in the fruit fly, Drosophila melanogaster, are dosage-dependent and resistance is selectable. While metallothionein-mediated sequestration has been extensively studied as a mechanism of cadmium resistance, a link between selection for resistance and an increased accumulation of cadmium has yet to be demonstrated. To address this need, we have selected wild-type flies for cadmium resistance for 20 generations and tested metal content using mass spectrometry. Resistant flies were observed to contain lower levels of cadmium, arguing for a mechanism of cadmium resistance that is not mediated by increased sequestration. This, coupled with genetic evidence suggesting the involvement of factors located on the X chromosome, suggests a gene other than metallothionein may be involved in resistance in this line.
authors.affiliation: Department of Biology, Loyola Marymount University, 1 LMU Dr, Los Angeles, CA, 90045, USA.
authors.forename: Austin H
authors.initials: AH
authors.lastname: Nguyen
authors.forename: Laura E
authors.initials: LE
authors.lastname: Altomare
authors.forename: M Catharine
authors.initials: MC
authors.lastname: McElwain
mesh_terms: D000818:Animals; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D019256:Cadmium Chloride / Q000378:metabolism / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics; D006801:Humans; D013058:Mass Spectrometry; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D012641:Selection, Genetic
chemical_list: D029721:Drosophila Proteins; D002104:Cadmium; D008668:Metallothionein; D019256:Cadmium Chloride