Alkylpurine-DNA-N-glycosylase knockout mice show increased susceptibility to induction of mutations by methyl methanesulfonate.
dc.contributor.author | Elder, Rhoderick H | |
dc.contributor.author | Jansen, J G | |
dc.contributor.author | Weeks, Robert J | |
dc.contributor.author | Willington, Mark | |
dc.contributor.author | Deans, Bryan | |
dc.contributor.author | Watson, Amanda J | |
dc.contributor.author | Mynett, Kurt J | |
dc.contributor.author | Bailey, John | |
dc.contributor.author | Cooper, Donald P | |
dc.contributor.author | Rafferty, Joseph A | |
dc.contributor.author | Heeran, Mel C | |
dc.contributor.author | Wijnhoven, S W | |
dc.contributor.author | Van Zeeland, A A | |
dc.contributor.author | Margison, Geoffrey P | |
dc.date.accessioned | 2010-02-25T10:52:41Z | |
dc.date.available | 2010-02-25T10:52:41Z | |
dc.date.issued | 1998-10 | |
dc.identifier.citation | Alkylpurine-DNA-N-glycosylase knockout mice show increased susceptibility to induction of mutations by methyl methanesulfonate. 1998, 18 (10):5828-37 Mol. Cell. Biol. | en |
dc.identifier.issn | 0270-7306 | |
dc.identifier.pmid | 9742100 | |
dc.identifier.uri | http://hdl.handle.net/10541/93018 | |
dc.description.abstract | Alkylpurine-DNA-N-glycosylase (APNG) null mice have been generated by homologous recombination in embryonic stem cells. The null status of the animals was confirmed at the mRNA level by reverse transcription-PCR and by the inability of cell extracts of tissues from the knockout (ko) animals to release 3-methyladenine (3-meA) or 7-methylguanine (7-meG) from 3H-methylated calf thymus DNA in vitro. Following treatment with DNA-methylating agents, increased persistence of 7-meG was found in liver sections of APNG ko mice in comparison with wild-type (wt) mice, demonstrating an in vivo phenotype for the APNG null animals. Unlike other null mutants of the base excision repair pathway, the APNG ko mice exhibit a very mild phenotype, show no outward abnormalities, are fertile, and have an apparently normal life span. Neither a difference in the number of leukocytes in peripheral blood nor a difference in the number of bone marrow polychromatic erythrocytes was found when ko and wt mice were exposed to methylating or chloroethylating agents. These agents also showed similar growth-inhibitory effects in primary embryonic fibroblasts isolated from ko and wt mice. However, treatment with methyl methanesulfonate resulted in three- to fourfold more hprt mutations in splenic T lymphocytes from APNG ko mice than in those from wt mice. These mutations were predominantly single-base-pair changes; in the ko mice, they consisted primarily of AT-->TA and GC-->TA transversions, which most likely are caused by 3-meA and 3- or 7-meG, respectively. These results clearly show an important role for APNG in attenuating the mutagenic effects of N-alkylpurines in vivo. | |
dc.language.iso | en | en |
dc.subject.mesh | Animals | |
dc.subject.mesh | Bone Marrow Cells | |
dc.subject.mesh | Cells, Cultured | |
dc.subject.mesh | DNA Glycosylases | |
dc.subject.mesh | Dacarbazine | |
dc.subject.mesh | Erythrocytes | |
dc.subject.mesh | Ethylnitrosourea | |
dc.subject.mesh | Female | |
dc.subject.mesh | Fibroblasts | |
dc.subject.mesh | Guanine | |
dc.subject.mesh | Hypoxanthine Phosphoribosyltransferase | |
dc.subject.mesh | Leukocyte Count | |
dc.subject.mesh | Liver | |
dc.subject.mesh | Male | |
dc.subject.mesh | Methyl Methanesulfonate | |
dc.subject.mesh | Mice | |
dc.subject.mesh | Mice, Inbred C57BL | |
dc.subject.mesh | Mice, Inbred DBA | |
dc.subject.mesh | Mice, Knockout | |
dc.subject.mesh | Mutagens | |
dc.subject.mesh | Mutation | |
dc.subject.mesh | N-Glycosyl Hydrolases | |
dc.title | Alkylpurine-DNA-N-glycosylase knockout mice show increased susceptibility to induction of mutations by methyl methanesulfonate. | en |
dc.type | Article | en |
dc.contributor.department | CRC Section of Genome Damage and Repair, Paterson Institute for Cancer Research, Christie Hospital (NHS) Trust, Manchester M20 4BX, United Kingdom. RElder@picr.man.ac.uk | en |
dc.identifier.journal | Molecular and Cellular Biology | en |
html.description.abstract | Alkylpurine-DNA-N-glycosylase (APNG) null mice have been generated by homologous recombination in embryonic stem cells. The null status of the animals was confirmed at the mRNA level by reverse transcription-PCR and by the inability of cell extracts of tissues from the knockout (ko) animals to release 3-methyladenine (3-meA) or 7-methylguanine (7-meG) from 3H-methylated calf thymus DNA in vitro. Following treatment with DNA-methylating agents, increased persistence of 7-meG was found in liver sections of APNG ko mice in comparison with wild-type (wt) mice, demonstrating an in vivo phenotype for the APNG null animals. Unlike other null mutants of the base excision repair pathway, the APNG ko mice exhibit a very mild phenotype, show no outward abnormalities, are fertile, and have an apparently normal life span. Neither a difference in the number of leukocytes in peripheral blood nor a difference in the number of bone marrow polychromatic erythrocytes was found when ko and wt mice were exposed to methylating or chloroethylating agents. These agents also showed similar growth-inhibitory effects in primary embryonic fibroblasts isolated from ko and wt mice. However, treatment with methyl methanesulfonate resulted in three- to fourfold more hprt mutations in splenic T lymphocytes from APNG ko mice than in those from wt mice. These mutations were predominantly single-base-pair changes; in the ko mice, they consisted primarily of AT-->TA and GC-->TA transversions, which most likely are caused by 3-meA and 3- or 7-meG, respectively. These results clearly show an important role for APNG in attenuating the mutagenic effects of N-alkylpurines in vivo. |