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DNA sequence analysis of hprt mutations in lymphocytes from Sprague‐Dawley rats treated with 7,12‐dimethylbenz[a]anthracene
Author(s) -
Heflich Robert H.,
Mittelstaedt Roberta A.,
Manjanatha Mugimane G.,
LynCook Lascelles E.,
Aidoo Anane
Publication year - 1996
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/(sici)1098-2280(1996)28:1<5::aid-em3>3.0.co;2-g
Subject(s) - heteroduplex , 7,12 dimethylbenz[a]anthracene , microbiology and biotechnology , exon , dmba , hypoxanthine guanine phosphoribosyltransferase , biology , mutation , dna , mutant , point mutation , transversion , gene , genetics , carcinogenesis
Treatment of female Sprague‐Dawley rats with the potent mammary gland carcinogen 7,12‐dimethylbenz[a]anthracene (DMBA) results in the formation of DNA adducts with dG and dA and in the induction of 6‐thioguanine‐resistant (TG′) lymphocyte mutants. In this study, we have examined the types of mutations induced in TG′ lymphocytes from DMBA‐treated rats. DNA from 263 TG′ lymphocyte clones was screened for mutations in exons 2, 3, and 8 of the hprt gene by polymerase chain reaction (PCR) amplification of the exons followed by heteroduplex analysis using denaturing gradient‐gel electrophoresis. Twenty‐five of the clones produced heteroduplexes in exon 2, 35 produced heteroduplexes in exon 3, and 36 produced heteroduplexes in exon 8. Direct sequence analysis of the heteroduplexes revealed 96 mutations, and at least 74 of these mutations were produced independently. Eighty‐five of the total mutations were simple base pair (bp) substitutions, with A → T and G → T transversions being the predominant types. Seven mutations were deletions, three were complex bp substitutions, and one was an insertion. The results suggest that the types of mutations produced by DMBA in rat lymphocytes are specific to the DNA adducts produced by this compound. © 1996 Wiley‐Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.