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dc.contributor.authorOckey, Charles H
dc.date.accessioned2011-06-22T09:10:47Z
dc.date.available2011-06-22T09:10:47Z
dc.date.issued1981
dc.identifier.citationMethyl methane-sulphonate (MMS) induced SCEs are reduced by the BrdU used to visualise them. 1981, 84 (2):243-56 Chromosomaen
dc.identifier.issn0009-5915
dc.identifier.pmid7035092
dc.identifier.urihttp://hdl.handle.net/10541/134137
dc.description.abstractSCE induction in synchronised CHO cells treated with methyl methane sulphonate (MMS) in G1 was studied over successive pairs of cell cycles by introducing bromodeoxyuridine (BrdU) at consecutive G1 stages. When individual cell cycle SCE values were calculated from the data, anomalous results were obtained with ratios of 1.0 : 1.8 : 2.1 for the first three cycles but a negative value for the fourth cycle. Further studies using different BrdU concentrations showed that MMS induced SCEs were reduced by values exceeding 50% in DNA containing high levels of incorporated BrdU. This reduction was dose dependent and accounted for the anomalous results obtained over successive cycles. Lesions leading to chromatid exchanges were also reduced by the same mechanism. SCEs induced by UV irradiation were also decreased but those induced by the cross-linking agent nitrogen mustard (HN2) remained unaffected. The results indicate that not only are SCE lesions induced by MMS, UV or HN2 expressed independently of the "spontaneous" SCEs induced by BrdU but that SCE lesions are multiple in nature. Mechanisms by which SCE lesions could be repaired in BrdU containing DNA are discussed. SCE lesions in MMS treated cells arrested in G1 with arginine deprived medium (ADM) are repaired without the presence of BrdU in the DNA. An opposite effect is seen however in the control cells, where SCEs are increased with time spent in ADM arrest. These interactions between the effects of MMS, BrdU and ADM arrest are discussed.
dc.language.isoenen
dc.subject.meshAnimals
dc.subject.meshBromodeoxyuridine
dc.subject.meshCell Line
dc.subject.meshCricetinae
dc.subject.meshCricetulus
dc.subject.meshCrossing Over, Genetic
dc.subject.meshCytological Techniques
dc.subject.meshFemale
dc.subject.meshMethyl Methanesulfonate
dc.subject.meshOvary
dc.subject.meshSister Chromatid Exchange
dc.titleMethyl methane-sulphonate (MMS) induced SCEs are reduced by the BrdU used to visualise them.en
dc.typeArticleen
dc.contributor.departmentPaterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester M20 9BX, Englanden
dc.identifier.journalChromosomaen
html.description.abstractSCE induction in synchronised CHO cells treated with methyl methane sulphonate (MMS) in G1 was studied over successive pairs of cell cycles by introducing bromodeoxyuridine (BrdU) at consecutive G1 stages. When individual cell cycle SCE values were calculated from the data, anomalous results were obtained with ratios of 1.0 : 1.8 : 2.1 for the first three cycles but a negative value for the fourth cycle. Further studies using different BrdU concentrations showed that MMS induced SCEs were reduced by values exceeding 50% in DNA containing high levels of incorporated BrdU. This reduction was dose dependent and accounted for the anomalous results obtained over successive cycles. Lesions leading to chromatid exchanges were also reduced by the same mechanism. SCEs induced by UV irradiation were also decreased but those induced by the cross-linking agent nitrogen mustard (HN2) remained unaffected. The results indicate that not only are SCE lesions induced by MMS, UV or HN2 expressed independently of the "spontaneous" SCEs induced by BrdU but that SCE lesions are multiple in nature. Mechanisms by which SCE lesions could be repaired in BrdU containing DNA are discussed. SCE lesions in MMS treated cells arrested in G1 with arginine deprived medium (ADM) are repaired without the presence of BrdU in the DNA. An opposite effect is seen however in the control cells, where SCEs are increased with time spent in ADM arrest. These interactions between the effects of MMS, BrdU and ADM arrest are discussed.


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