title: Genotypic mutation analysis in the p53 gene of benzo[a]pyrene-treated European flounder (Platichthys flesus).
abstract: We have applied a genotypic mutation detection system (the Restriction Site Mutation (RSM) assay) to detect mutations in the marine teleost flounder (Platichthys flesus). The aim of this study was to evaluate this species as an environmental indicator of genotoxic exposure. We have used the model genotoxin benzo[a]pyrene (B[a]P) to determine the limits of mutation detection in the p53 gene of flounder liver DNA. This study has revealed two important findings. Firstly, we were able to demonstrate that a polymorphism exists in the TaqI restriction site of exon 8 of the flounder p53 gene at codon 243. This polymorphic allele was present as a heterozygote at a mean frequency of 15%, whereas 85% carried the homozygous wild type sequence. Secondly, we established that B[a]P treatment resulted in specific mutational events at the adenine base of the same TaqI site, contrasting previous reports stating that there was a guanine preference for this chemical in mammalian DNA. This difference in mutation specificity may possibly be accounted for by sequence specific factors or by species differences in metabolic activation and/or DNA repair and are worthy of further study.
authors.affiliation: Institute of Food Analysis and Research (IIAA), University of Santiago, Santiago de Compostela, Spain.
authors.forename: R A
authors.initials: RA
authors.lastname: Sueiro
authors.forename: G J
authors.initials: GJ
authors.lastname: Jenkins
authors.forename: B P
authors.initials: BP
authors.lastname: Lyons
authors.forename: J S
authors.initials: JS
authors.lastname: Harvey
authors.forename: J M
authors.initials: JM
authors.lastname: Parry
mesh_terms: D000225:Adenine; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D001564:Benzo(a)pyrene / Q000633:toxicity*; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005432:Flounder / Q000235:genetics*; D005838:Genotype; D006579:Heterozygote; D016297:Mutagenesis, Site-Directed; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity; D009154:Mutation / Q000187:drug effects; D017354:Point Mutation; D011110:Polymorphism, Genetic; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D009153:Mutagens; D016159:Tumor Suppressor Protein p53; D001564:Benzo(a)pyrene; D004247:DNA; D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases; D000225:Adenine