Mutation spectrum of o-aminoazotoluene in the cII gene of lambda/lacZ transgenic mice (MutaMouse).
The o-aminoazotoluene (AAT) has been evaluated as a possible human carcinogen by the International Agency for Research on Cancer. In rodents, it is carcinogenic mainly in the liver, and also in lung following long term administration. We previously examined in lambda/lacZ transgenic mice for the induction of lacZ mutations in liver, lung, urinary bladder, colon, kidney, bone marrow, and testis. AAT induced gene mutations strongly in the liver and colon. In the present report, we reveal the molecular nature of mutations induced by AAT in the lambda cII gene (the cII gene, a phenotypically selectable marker in the lambda transgene, has 294bp, which makes it easier to sequence than the original target, the 3kb lacZ gene). The cII mutant frequency in liver and colon was five and nine times higher, respectively, in AAT-treated mice than in control mice. Sequence analysis revealed that AAT induced G:C to T:A transversions, whereas spontaneous mutations consisted primarily of G:C to A:T transitions at CpG sites.
Kohara
A
A
Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, 158-8501, Tokyo, Japan.
Suzuki
T
T
Honma
M
M
Hirano
N
N
Ohsawa
K
K
Ohwada
T
T
Hayashi
M
M
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D007763:Lac Operon; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009153:Mutagens / Q000633:toxicity*; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics*; D014764:Viral Proteins; D009762:o-Aminoazotoluene / Q000633:toxicity*
D017931:DNA Primers; D009153:Mutagens; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; D009762:o-Aminoazotoluene