title: Long-term exposure to environmentally relevant doses of methyl-tert-butyl ether causes significant reproductive dysfunction in the zebrafish (Danio rerio).
abstract: Methyl-tert-butyl ether (MTBE), an anthropogenic chemical used as a gasoline additive, is being detected at an increasing frequency in the environment. The acute lethal concentration that kills 50% of the fish test population and the chronic effects of exposure to MTBE were investigated in the zebrafish (Danio rerio). Chronic exposure over three weeks to effective MTBE conceritrations as low as 0.11 mg/L induced a significant increase in the vitellogenin concentration of male fish. The impact of a chronic, eight-week exposure at effective concentrations ranging from 0.44 to 220 mg/L had no significant effect on fecundity, fertilization, or hatch rate but highly significant impacts on sperm motility. Spermatozoa of all MTBE-exposure groups showed a significantly lower straight-line velocity and lower average path velocity compared to those of the nonexposed group. These results suggest that chronic exposure to MTBE negatively affects fish sperm motility at concentrations that are environmentally relevant and several orders of magnitude lower than concentrations inducing acute effects.
authors.affiliation: Flemish Institute for Technological Research (Vito), Boeretang 200, B 2400 Mol, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Moreels
authors.forename: Karen
authors.initials: K
authors.lastname: Van Cauwenberghe
authors.forename: Bruno
authors.initials: B
authors.lastname: Debaere
authors.forename: Eugène
authors.initials: E
authors.lastname: Rurangwa
authors.forename: Nico
authors.initials: N
authors.lastname: Vromant
authors.forename: Leen
authors.initials: L
authors.lastname: Bastiaens
authors.forename: Ludo
authors.initials: L
authors.lastname: Diels
authors.forename: Dirk
authors.initials: D
authors.lastname: Springael
authors.forename: Roel
authors.initials: R
authors.lastname: Merckx
authors.forename: Frans
authors.initials: F
authors.lastname: Ollevier
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D007928:Lethal Dose 50; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage* / Q000378:metabolism / Q000633:toxicity*; D010063:Ovum / Q000187:drug effects; D012098:Reproduction / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects; D015027:Zebrafish
chemical_list: D008738:Methyl Ethers; C043243:methyl tert-butyl ether