Publication Abstract

Genotypic mutation analysis of the p53 gene of benzo(a)pyrene treated European flounder

R.A. Sueiro, G.J.S. Jenkins, B.P. Lyons, J.S. Harvey and J.M. Parry

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.

Reference:

R.A. Sueiro, G.J.S. Jenkins, B.P. Lyons, J.S. Harvey and J.M. Parry, 2000. Genotypic mutation analysis of the p53 gene of benzo(a)pyrene treated European flounder. Mutation Research - Genetic Toxicology and Environmental Mutagenesis, 468(1): 63-71