Correlation between lethality and DNA single-strand breaks in Bacillus subtilis cells treated with N-methyl-N'-nitro-N-nitrosoguanidine |
| |
| Authors: | D L Dugle C E Campbell B E Meeker C J Gillespie |
| |
| Institution: | Medical Biophysics Branch, Atomic Energy of Canada Limited, Whiteshell Nuclear Research Establishment, Pinawa, Manitoba Canada |
| |
| Abstract: | The effects of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) treatment two Bacillus subtilis strains which exhibit different UV sensitivities were monitored at both the cellular (survival) and subcellular (DNA strand break) levels. The MNNG-induced single strand DNA breaks (SSB) in either strain, as measured by alkaline sucrose gradient centrifugation, were shown to be well correlated with lethality. These DNA lesions were shown by a computer simulation to be randomly induced. Cell survival after MNNG treatment is inversely related to the number of replication forks per cell which in turn depends upon the doubling time of the culture and the growth phase. The production of single-strand breaks and cell killing are proportional to the log of the initial MNNG concentration and may imply that decomposition of the mutagen is (pseudo) second order. |
| |
| Keywords: | BP breakage parameter MNNG MW molecular weight PEA β-phenethyl alcohol SMM Spizizen's minimal medium SSB single-strand DNA breaks Author to whom all correspondence should be sent |
| 本文献已被 ScienceDirect PubMed 等数据库收录！ |
