Abstract
Transgenic B6C3F1 mice carrying a lacI target gene were exposed to acute and multiple doses of ethylnitrosourea (ENU), and germ cells from the seminiferous tubules were assayed for mutation 3 and 90 days after treatment. Relative to untreated controls, the mutation frequency increased 3.2- and 19.9-fold at 3 and 90 days after treatment, respectively. Mutant lacI genes recovered from untreated and treated groups were sequenced, and the spectra of mutations were determined. Eighty-five percent (11/13) of the spontaneous mutations resulted in G.C-->A.T transitions, all of which occurred at CpG dinucleotides. Fifteen of 22 sites (68%) found mutated 3 days after ENU treatment occurred at G.C base pairs, although some of these are expected to be spontaneous mutations. Ninety days after treatment, 13 of 19 sites (68%) found mutated occurred at A.T base pairs. The mutation spectra seen are consistent with proposed mechanisms of ENU mutagenesis and correlate with the in vivo spectra seen in ENU studies by using transmissibility assays and the hprt gene. These findings represent significant progress toward defining the in vivo spectra of ENU mutagenesis in mammalian germ cells.
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- Ariel M., McCarrey J., Cedar H. Methylation patterns of testis-specific genes. Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2317–2321. doi: 10.1073/pnas.88.6.2317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bhanot O. S., Grevatt P. C., Donahue J. M., Gabrielides C. N., Solomon J. J. In vitro DNA replication implicates O2-ethyldeoxythymidine in transversion mutagenesis by ethylating agents. Nucleic Acids Res. 1992 Feb 11;20(3):587–594. doi: 10.1093/nar/20.3.587. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bronstein S. M., Skopek T. R., Swenberg J. A. Efficient repair of O6-ethylguanine, but not O4-ethylthymine or O2-ethylthymine, is dependent upon O6-alkylguanine-DNA alkyltransferase and nucleotide excision repair activities in human cells. Cancer Res. 1992 Apr 1;52(7):2008–2011. [PubMed] [Google Scholar]
- Duncan B. K., Miller J. H. Mutagenic deamination of cytosine residues in DNA. Nature. 1980 Oct 9;287(5782):560–561. doi: 10.1038/287560a0. [DOI] [PubMed] [Google Scholar]
- Ehling U. H., Favor J., Kratochvilova J., Neuhäuser-Klaus A. Dominant cataract mutations and specific-locus mutations in mice induced by radiation or ethylnitrosourea. Mutat Res. 1982 Feb 22;92(1-2):181–192. doi: 10.1016/0027-5107(82)90222-6. [DOI] [PubMed] [Google Scholar]
- Ehling U. H. Genetic risk assessment. Annu Rev Genet. 1991;25:255–280. doi: 10.1146/annurev.ge.25.120191.001351. [DOI] [PubMed] [Google Scholar]
- Farabaugh P. J. Sequence of the lacI gene. Nature. 1978 Aug 24;274(5673):765–769. doi: 10.1038/274765a0. [DOI] [PubMed] [Google Scholar]
- Favor J. A comparison of the dominant cataract and recessive specific-locus mutation rates induced by treatment of male mice with ethylnitrosourea. Mutat Res. 1983 Aug;110(2):367–382. doi: 10.1016/0027-5107(83)90153-7. [DOI] [PubMed] [Google Scholar]
- Favor J. A comparison of the mutation rates to dominant and recessive alleles in germ cells of the mouse. Prog Clin Biol Res. 1986;209B:519–526. [PubMed] [Google Scholar]
- Favor J. Risk estimation based on germ-cell mutations in animals. Genome. 1989;31(2):844–852. doi: 10.1139/g89-149. [DOI] [PubMed] [Google Scholar]
- Favor J., Sund M., Neuhäuser-Klaus A., Ehling U. H. A dose-response analysis of ethylnitrosourea-induced recessive specific-locus mutations in treated spermatogonia of the mouse. Mutat Res. 1990 Jul;231(1):47–54. doi: 10.1016/0027-5107(90)90175-4. [DOI] [PubMed] [Google Scholar]
- Hanawalt P. C. Heterogeneity of DNA repair at the gene level. Mutat Res. 1991 Apr;247(2):203–211. doi: 10.1016/0027-5107(91)90016-h. [DOI] [PubMed] [Google Scholar]
- Hitotsumachi S., Carpenter D. A., Russell W. L. Dose-repetition increases the mutagenic effectiveness of N-ethyl-N-nitrosourea in mouse spermatogonia. Proc Natl Acad Sci U S A. 1985 Oct;82(19):6619–6621. doi: 10.1073/pnas.82.19.6619. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Impellizzeri K. J., Anderson B., Burgers P. M. The spectrum of spontaneous mutations in a Saccharomyces cerevisiae uracil-DNA-glycosylase mutant limits the function of this enzyme to cytosine deamination repair. J Bacteriol. 1991 Nov;173(21):6807–6810. doi: 10.1128/jb.173.21.6807-6810.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klein J. C., Bleeker M. J., Lutgerink J. T., van Dijk W. J., Brugghe H. F., van den Elst H., van der Marel G. A., van Boom J. H., Westra J. G., Berns A. J. Use of shuttle vectors to study the molecular processing of defined carcinogen-induced DNA damage: mutagenicity of single O4-ethylthymine adducts in HeLa cells. Nucleic Acids Res. 1990 Jul 25;18(14):4131–4137. doi: 10.1093/nar/18.14.4131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kohler S. W., Provost G. S., Fieck A., Kretz P. L., Bullock W. O., Putman D. L., Sorge J. A., Short J. M. Analysis of spontaneous and induced mutations in transgenic mice using a lambda ZAP/lacI shuttle vector. Environ Mol Mutagen. 1991;18(4):316–321. doi: 10.1002/em.2850180421. [DOI] [PubMed] [Google Scholar]
- Kohler S. W., Provost G. S., Fieck A., Kretz P. L., Bullock W. O., Sorge J. A., Putman D. L., Short J. M. Spectra of spontaneous and mutagen-induced mutations in the lacI gene in transgenic mice. Proc Natl Acad Sci U S A. 1991 Sep 15;88(18):7958–7962. doi: 10.1073/pnas.88.18.7958. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewis S. E., Johnson F. M., Skow L. C., Popp D., Barnett L. B., Popp R. A. A mutation in the beta-globin gene detected in the progeny of a female mouse treated with ethylnitrosourea. Proc Natl Acad Sci U S A. 1985 Sep;82(17):5829–5831. doi: 10.1073/pnas.82.17.5829. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller J. H., Schmeissner U. Genetic studies of the lac repressor. X. Analysis of missense mutations in the lacI gene. J Mol Biol. 1979 Jun 25;131(2):223–248. doi: 10.1016/0022-2836(79)90074-3. [DOI] [PubMed] [Google Scholar]
- Mirsalis J. C., Provost G. S., Matthews C. D., Hamner R. T., Schindler J. E., O'Loughlin K. G., MacGregor J. T., Short J. M. Induction of hepatic mutations in lacI transgenic mice. Mutagenesis. 1993 May;8(3):265–271. doi: 10.1093/mutage/8.3.265. [DOI] [PubMed] [Google Scholar]
- Montesano R. Alkylation of DNA and tissue specificity in nitrosamine carcinogenesis. J Supramol Struct Cell Biochem. 1981;17(3):259–273. doi: 10.1002/jsscb.380170307. [DOI] [PubMed] [Google Scholar]
- OAKBERG E. F. Duration of spermatogenesis in the mouse and timing of stages of the cycle of the seminiferous epithelium. Am J Anat. 1956 Nov;99(3):507–516. doi: 10.1002/aja.1000990307. [DOI] [PubMed] [Google Scholar]
- Peters J., Andrews S. J., Loutit J. F., Clegg J. B. A mouse beta-globin mutant that is an exact model of hemoglobin Rainier in man. Genetics. 1985 Aug;110(4):709–721. doi: 10.1093/genetics/110.4.709. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Popp R. A., Bailiff E. G., Skow L. C., Johnson F. M., Lewis S. E. Analysis of a mouse alpha-globin gene mutation induced by ethylnitrosourea. Genetics. 1983 Sep;105(1):157–167. doi: 10.1093/genetics/105.1.157. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Provost G. S., Kretz P. L., Hamner R. T., Matthews C. D., Rogers B. J., Lundberg K. S., Dycaico M. J., Short J. M. Transgenic systems for in vivo mutation analysis. Mutat Res. 1993 Jul;288(1):133–149. doi: 10.1016/0027-5107(93)90215-2. [DOI] [PubMed] [Google Scholar]
- RUSSELL W. L. X-ray-induced mutations in mice. Cold Spring Harb Symp Quant Biol. 1951;16:327–336. doi: 10.1101/sqb.1951.016.01.024. [DOI] [PubMed] [Google Scholar]
- Richardson K. K., Richardson F. C., Crosby R. M., Swenberg J. A., Skopek T. R. DNA base changes and alkylation following in vivo exposure of Escherichia coli to N-methyl-N-nitrosourea or N-ethyl-N-nitrosourea. Proc Natl Acad Sci U S A. 1987 Jan;84(2):344–348. doi: 10.1073/pnas.84.2.344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rideout W. M., 3rd, Coetzee G. A., Olumi A. F., Jones P. A. 5-Methylcytosine as an endogenous mutagen in the human LDL receptor and p53 genes. Science. 1990 Sep 14;249(4974):1288–1290. doi: 10.1126/science.1697983. [DOI] [PubMed] [Google Scholar]
- Russell W. L., Kelly E. M., Hunsicker P. R., Bangham J. W., Maddux S. C., Phipps E. L. Specific-locus test shows ethylnitrosourea to be the most potent mutagen in the mouse. Proc Natl Acad Sci U S A. 1979 Nov;76(11):5818–5819. doi: 10.1073/pnas.76.11.5818. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schaaper R. M., Danforth B. N., Glickman B. W. Mechanisms of spontaneous mutagenesis: an analysis of the spectrum of spontaneous mutation in the Escherichia coli lacI gene. J Mol Biol. 1986 May 20;189(2):273–284. doi: 10.1016/0022-2836(86)90509-7. [DOI] [PubMed] [Google Scholar]
- Schaaper R. M., Dunn R. L. Spontaneous mutation in the Escherichia coli lacI gene. Genetics. 1991 Oct;129(2):317–326. doi: 10.1093/genetics/129.2.317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sega G. A., Rohrer C. R., Harvey H. R., Jetton A. E. Chemical dosimetry of ethyl nitrosourea in the mouse testis. Mutat Res. 1986 Jan-Feb;159(1-2):65–74. doi: 10.1016/0027-5107(86)90113-2. [DOI] [PubMed] [Google Scholar]
- Singer B., Fraenkel-Conrat H., Kuśmierek J. T. Preparation and template activities of polynucleotides containing O2- and O4-alkyluridine. Proc Natl Acad Sci U S A. 1978 Apr;75(4):1722–1726. doi: 10.1073/pnas.75.4.1722. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Skopek T. R., Walker V. E., Cochrane J. E., Craft T. R., Cariello N. F. Mutational spectrum at the Hprt locus in splenic T cells of B6C3F1 mice exposed to N-ethyl-N-nitrosourea. Proc Natl Acad Sci U S A. 1992 Sep 1;89(17):7866–7870. doi: 10.1073/pnas.89.17.7866. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Su L. K., Kinzler K. W., Vogelstein B., Preisinger A. C., Moser A. R., Luongo C., Gould K. A., Dove W. F. Multiple intestinal neoplasia caused by a mutation in the murine homolog of the APC gene. Science. 1992 May 1;256(5057):668–670. doi: 10.1126/science.1350108. [DOI] [PubMed] [Google Scholar]
- Tao K. S., Urlando C., Heddle J. A. Comparison of somatic mutation in a transgenic versus host locus. Proc Natl Acad Sci U S A. 1993 Nov 15;90(22):10681–10685. doi: 10.1073/pnas.90.22.10681. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang X. Y., Loflin P. T., Gehrke C. W., Andrews P. A., Ehrlich M. Hypermethylation of human DNA sequences in embryonal carcinoma cells and somatic tissues but not in sperm. Nucleic Acids Res. 1987 Nov 25;15(22):9429–9449. doi: 10.1093/nar/15.22.9429. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang X. Y., Wang R. Y., Ehrlich M. Human DNA sequences exhibiting gamete-specific hypomethylation. Nucleic Acids Res. 1985 Jul 11;13(13):4837–4851. doi: 10.1093/nar/13.13.4837. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van Zeeland A. A., Mohn G. R., Neuhäuser-Klaus A., Ehling U. H. Quantitative comparison of genetic effects of ethylating agents on the basis of DNA adduct formation. Use of O6-ethylguanine as molecular dosimeter for extrapolation from cells in culture to the mouse. Environ Health Perspect. 1985 Oct;62:163–169. doi: 10.1289/ehp.8562163. [DOI] [PMC free article] [PubMed] [Google Scholar]