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A recombinagenic effect of strychnine in Salmonella typhimurium
Author(s) -
Hoffmann George R.,
Sprague Kathleen M.,
Wrobel John A.,
Wroblewski Diane H.
Publication year - 1987
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.2850100105
Subject(s) - strychnine , gene duplication , brucine , genetics , biology , allele , strain (injury) , mutagenesis , mutation , gene , biochemistry , anatomy
Abstract The aroC321 allele in Salmonella typhimurium permits a positive selection for genetic duplications. Bacteria that contain a large genetic duplication are detected as tryptophan prototrophs in aroC321 strains and occur at a spontaneous frequency greater than 1/10 4 cells plated on the selection medium. Duplications originate by a recombinational mechanism, and the induction of duplications by chemicals or radiation may therefore be considered to be a recombinagenic effect. We have found that strychnine is a potent recombinagen in this system; it causes a dose‐dependent increase in the frequency of genetic duplications, and very high frequencies of duplications are recovered at high doses. In contrast, brucine, the 2,3‐dimethoxy derivative of strychnine, caused no increase in duplication frequencies under the identical conditions.