title: Mutational spectra of benzo[a]pyrene and MeIQx in rpsL transgenic zebrafish embryos.
abstract: To evaluate the rpsL transgenic zebrafish (Brachydanio rerio) mutation assay, we treated the embryos with benzo[a]pyrene (B[a]P) (10 microg/ml) or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (300 microg/ml) for 16h and determined the mutation spectra. These treatments were previously reported to induce mutant frequencies that were 4.3 and 2.4 times the control value, respectively. In the B[a]P-treated group, half of the mutations were single base substitutions, 74% of which occurred at G:C base pairs. Among G:C base pair substitutions, G:C to T:A and G: C to C:G transversions were predominant, suggesting that B[a]P induced mutations in zebrafish embryos by mechanisms previously described in mammalian tissues. In the MeIQx-treated group, about 60% of the mutations were deletions. Some specific mutations were found, but the compound primarily amplified the background mutation level; improvement in the conditions of treatment may be required for elucidating MeIQx-mutagenesis in this system. This study showed that transgenic zebrafish may be a useful tool for detecting mutagens in aquatic environments and for elucidating mutagenic mechanisms.
authors.affiliation: Division of Environmental Health Sciences, National Institute for Environmental Studies, Onogawa, Tsukuba 305-0053, Japan. amanuma@nies.go.jp
authors.forename: Kimiko
authors.initials: K
authors.lastname: Amanuma
authors.forename: Suguru
authors.initials: S
authors.lastname: Tone
authors.forename: Hotaka
authors.initials: H
authors.lastname: Saito
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Shigeoka
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Aoki
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001564:Benzo(a)pyrene / Q000633:toxicity*; D009153:Mutagens / Q000633:toxicity*; D009154:Mutation; D011810:Quinoxalines / Q000633:toxicity*; D012269:Ribosomal Proteins / Q000235:genetics*; D015027:Zebrafish / Q000235:genetics*
chemical_list: D009153:Mutagens; D011810:Quinoxalines; D012269:Ribosomal Proteins; C034212:ribosomal protein S12; D001564:Benzo(a)pyrene; C036990:2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline