Spontaneous mutation at codon 61 of the Ha-ras gene in the nascent liver of B6C3F1, C3H/He and C57BL/6 mice.
DNA was isolated from the liver of young B6C3F1, C3H/He and C57BL/6 mice, 6-9 weeks old. A portion of exon 2 of Ha-ras was amplified by PCR allele-specific amplification. The PCR product was identified by (a) size, (b) presence of a diagnostic restriction site, and (c) direct sequencing. Our results indicate that nascent mouse liver bears a subpopulation of cells which contain a mutation in codon 61 of Ha-ras, specifically an A to G transition at position 2. Therefore, the detection of this mutation in chemically induced mouse liver tumors does not demonstrate that the chemical in question acts as a mutagen. It might act by a nongenotoxic mechanism, i.e., by facilitating a clonal expression of cells bearing this spontaneous mutation.
Moulds
B A
BA
Department of Pharmacology and Toxicology, Michigan State University, East Lansing 48824-1317.
Goodman
J I
JI
D000818:Animals; D001483:Base Sequence; D003062:Codon; D004247:DNA; D005260:Female; D011905:Genes, ras; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009154:Mutation
D003062:Codon; D004247:DNA