title: Mutation induction in Haemophilus influenzae by ICR-191. I. Development of a detection system for frameshift mutations.
abstract: The investigation of mutagenic mechanisms in Haemophilus influenzae has been confined until now to mutagens that normally produce mainly base pair substitutions. This paper describes the development of a system suitable for detecting frameshift mutations induced by ICR-191. The system involves reversions from thymidine dependence to thymidine independence. Evidence is presented from a comparison of the responses to ICR-191 and to N-methyl-N'-nitro-N-nitrosoguanidine that the system is specific for frameshift mutations. The genetic recombination involved in transformation leads to a marked increase in "spontaneous" reversion of the frameshift mutations but not of the base substitution mutations. Presumably, this is a consequence of mispairing, with consequent change in the number of bases, during the recombination.
mesh_terms: D000585:Aminacrine / Q000031:analogs & derivatives / Q000494:pharmacology*; D000609:Aminoacridines / Q000494:pharmacology*; D001431:Bacteriological Techniques; D005815:Genetic Code; D005821:Genetic Techniques; D006193:Haemophilus influenzae / Q000235:genetics*; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009152:Mutagenicity Tests / Q000379:methods*; D009153:Mutagens; D009154:Mutation; D009588:Nitrogen Mustard Compounds / Q000494:pharmacology*; D014176:Protein Biosynthesis
chemical_list: D000609:Aminoacridines; D009153:Mutagens; D009588:Nitrogen Mustard Compounds; D008769:Methylnitronitrosoguanidine; D000585:Aminacrine; C004294:acridine half-mustard