Berkowitz D, Hushon J M, Whitfield H J, Roth J, Ames B N
J Bacteriol. 1968 Jul;96(1):215-20. doi: 10.1128/jb.96.1.215-220.1968.
A method has been devised for the rapid identification of nonsense mutations (UAG, UAA, UGA codons) in Salmonella. The mutations to be tested are reverted, and the revertants are replica-printed onto lactose plates spread with lawns of tester strains. These tester strains contain F' lac episomes with nonsense mutations in the episomal Z gene. The revertants are infected with the episome from the tester strain lawn. Because S. typhimurium is unable to ferment lactose, only those revertants which have nonsense suppressors are able to grow on lactose. If colonies appear on the lactose plate, it may be concluded that the original strain carries a nonsense mutation, since nonsense suppressors suppress the mutant phenotype.
已设计出一种用于快速鉴定沙门氏菌中无义突变（UAG、UAA、UGA密码子）的方法。将待测试的突变进行回复突变，然后将回复子影印接种到涂布有测试菌株菌苔的乳糖平板上。这些测试菌株含有F' lac附加体，其附加体Z基因中存在无义突变。回复子被来自测试菌株菌苔的附加体感染。由于鼠伤寒沙门氏菌不能发酵乳糖，只有那些具有无义抑制子的回复子才能在乳糖上生长。如果乳糖平板上出现菌落，则可以得出结论，原始菌株携带无义突变，因为无义抑制子抑制了突变表型。
