Localization of chromosome breakpoints induced by AluI and BamHI in Chinese hamster ovary cells treated in the G1 phase of the cell cycle.
Intact Chinese hamster ovary cells were exposed to the restriction endonucleases (REs) AluI or BamHI. In metaphase spreads from these cells, 300 breakpoints per RE were localized in G-banded chromosome type aberrations (dicentrics, translocations, rings, terminal and interstitial deletions). The majority of breakpoints induced by both REs were localized in G-light bands and showed a similar distribution of breakpoint clusters. RE digestion of metaphase spreads with AluI induced C-banding, and with BamHI G-banding. The data indicate that nuclease sensitive sites associated with active genes are mainly responsible for the distribution of breakpoints.
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División de Citogenética Humana y Microscopía Cuantitativa, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
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D000818:Animals; D016466:CHO Cells; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D006224:Cricetinae; D015245:Deoxyribonuclease BamHI / Q000494:pharmacology*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000494:pharmacology*; D016193:G1 Phase
D015245:Deoxyribonuclease BamHI; C024669:endodeoxyribonuclease AluI; D015252:Deoxyribonucleases, Type II Site-Specific