Gairola C C, Griffith R B
Cancer Detect Prev. 1981;4(1-4):53-7.
A procedure for determining the effect of fresh cigarette smoke on gene conversion in yeast. Saccharomyces cerevisiae D7, is described. Cigarette smoke, generated by a 2-sec, 40-ml puff, once per minute, was puffed into an open-end tube. The smoke was drawn through an exposure vessel containing a continuously stirred, stationary-phase yeast cell suspension, 1-58 sec after generation. Frequency of gene conversion was estimated in samples taken at intervals after the start of exposure. Under these conditions, a five-fold increase in mitotic gene conversion in yeast strain D7 was obtained from exposure to 20 puffs of fresh whole smoke from University of Kentucky Reference Cigarettes (2R1), to 75 puffs from the gas phase of these cigarettes, and to 45 puffs from an acetate filter version (2R1F). Selective removal of genetically active components by acetate filters is suggested since the reduction in recombinogenic activity (55%) is greater than the reduction in total particulate matter yield (25%) of the cigarette. The results indicate that 1) the procedure provides a practical bioassay for determining the effects of fresh smoke on gene conversion in yeast, without external metabolic activation; 2) the gas phase of smoke has recombinogenic activity; and 3) standard acetate filters may selectively remove genetically active components of cigarette smoke.
描述了一种测定新鲜香烟烟雾对酵母（酿酒酵母D7）基因转换影响的方法。由每分钟抽吸一次、每次2秒、40毫升的抽吸产生的香烟烟雾被吹入开口管中。烟雾在产生后1至58秒被抽吸通过一个装有持续搅拌的静止期酵母细胞悬浮液的暴露容器。在暴露开始后的不同时间间隔采集样本，估计基因转换频率。在这些条件下，酵母菌株D7的有丝分裂基因转换频率因暴露于肯塔基大学参考香烟（2R1）的20口新鲜全烟雾、这些香烟气相的75口烟雾以及醋酸纤维过滤嘴版本（2R1F）的45口烟雾而增加了五倍。由于醋酸纤维过滤嘴对重组活性的降低（55%）大于香烟总颗粒物产量的降低（25%），表明醋酸纤维过滤嘴可选择性去除具有遗传活性的成分。结果表明：1）该方法提供了一种实用的生物测定法，用于测定新鲜烟雾对酵母基因转换的影响，无需外部代谢激活；2）烟雾气相具有重组活性；3）标准醋酸纤维过滤嘴可选择性去除香烟烟雾中的遗传活性成分。
