Abstract
The effects of nitrosoguanidine on Bacillus subtilis were studied. Lethal damage produced by nitrosoguanidine was repairable in the sense that the repair was inhibited by acriflavine. Mutation was induced more efficiently at the initial period of the treatment when the killing effect was not high. The repairable damage seems to have little connection to the potent mutagenic action of nitrosoguanidine. It was also found that less amount of DNA could be isolated from nitrosoguanidine-treated cells, and the genetic linkage was lowered in the DNA isolated from treated cells, as compared with DNA isolated from untreated cells. It was postulated from these results that nitrosoguanidine would produce some unknown damage on DNA or on some other cellular components which would then act to induce mutation at very high efficiency.
