title: Restriction site mutation (RSM) analysis of 2-acetylaminofluorene (2-AAF)-induced mouse liver mutations and comparison with the measurement of in vivo micronucleus induction in the bone marrows of (2-AAF)-treated mice.
abstract: We report here the successful application of the restriction site mutation (RSM) assay in detecting 2-acetylaminofluorene (2-AAF)-induced mouse liver mutations. A total of seven 2-AAF-induced liver mutations were detected out of a total of 304 analyses performed on 2-AAF-treated liver tissue. No mutations were detected in the 190 RSM analyses performed on untreated liver tissue. The 2-AAF-induced point mutations comprised 60% GC-->TA transversions, 30% GC-->AT transitions, 10% GC-->CG transversions, and 1 insertional event was also detected. All seven mutations were detected in intron 6 of the mouse p53 gene, with no mutations detectable in exons 4 or 5, supporting our previous data on the greater mutability of intron regions. In addition to the RSM analysis, we also report the application of the in vivo bone marrow micronucleus assay in detecting the clastogenicity of 2-AAF. We detected a small, but statistically significant, increase in the number of micronuclei induced by 2-AAF, but only after 2,000 cells were scored. This also confirms previous data showing that 2-AAF is a weak clastogen. Finally, we attempted to compare the sensitivity of the two assays to 2-AAF-induced genotoxicity, as had been previously undertaken with ENU. Both assays detected genotoxicity in their respective tissues; however, different endpoints were analysed. The RSM assay appears to be more adaptable than the micronucleus assay, due to its tissue and organism independence and has the potential to provide more molecular information on genotoxicity. Teratogenesis Carcinog. Mutagen. 20:107-117, 2000.
authors.affiliation: University of Wales Swansea, Singleton Park, Swansea, UK. g.j.jenkins@swansea.ac.uk
authors.forename: G J
authors.initials: GJ
authors.lastname: Jenkins
authors.forename: J M
authors.initials: JM
authors.lastname: Parry
mesh_terms: D015073:2-Acetylaminofluorene / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D001711:Biotransformation; D001853:Bone Marrow / Q000187:drug effects*; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D015252:Deoxyribonucleases, Type II Site-Specific; D005091:Exons / Q000235:genetics; D016368:Frameshift Mutation; D016158:Genes, p53 / Q000187:drug effects; D007438:Introns / Q000235:genetics; D008099:Liver / Q000187:drug effects*; D008297:Male; D051379:Mice; D015162:Micronucleus Tests; D015394:Molecular Structure; D016296:Mutagenesis; D016254:Mutagenesis, Insertional; D009152:Mutagenicity Tests; D009153:Mutagens / Q000737:chemistry / Q000633:toxicity*; D009928:Organ Specificity; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011355:Prodrugs / Q000633:toxicity*; D015183:Restriction Mapping; D012680:Sensitivity and Specificity
chemical_list: D009153:Mutagens; D011355:Prodrugs; D004247:DNA; D015073:2-Acetylaminofluorene; D015252:Deoxyribonucleases, Type II Site-Specific; C024403:GGCC-specific type II deoxyribonucleases; C051481:GRGCYC-specific type II deoxyribonucleases