Ultraviolet light, mitomycin C and nitrous acid induce genetic instability in Streptomyces ambofaciens ATCC23877.
In Streptomyces ambofaciens ATCC23877, pigment-negative (Pig-) mutants occur at high frequency (about 0.7 x 10(-2)) in the progenies of wild-type colonies. Furthermore, the offspring of these Pig- mutants can either be phenotypically homogeneous or hypervariable (with no preponderant phenotype). Pig- mutants can also lack antibiotic production and present aerial mycelium deficiency, auxotrophy for arginine, oversensitivity to either ultraviolet (UV) light or mitomycin C and resistance to either novobiocin or nosiheptide. This genetic instability is related to both amplified DNA sequences and deletions. Mutagens such as UV light, mitomycin C and nitrous acid induced genetic instability and increased the Pig- mutant frequency to almost 30% even at a high survival rate. Induced Pig- mutants exhibited the same features as the spontaneous ones at both phenotypic and molecular levels. The frequency of detected genomic rearrangements after treatment was higher than 10%. We postulate that an SOS-like system is involved in the induction of genetic instability in S. ambofaciens.
Volff
J N
JN
Laboratoire de Génétique et Microbiologie, Faculté des Sciences, Université de Nancy I, Vandoeuvre-lès-Nancy, France.
Vandewiele
D
D
Simonet
J M
JM
Decaris
B
B
D015321:Gene Rearrangement; D005798:Genes, Bacterial / Q000187:drug effects / Q000528:radiation effects; D016685:Mitomycin / Q000494:pharmacology*; D009154:Mutation; D009608:Nitrous Acid / Q000494:pharmacology*; D013014:SOS Response, Genetics; D013302:Streptomyces / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
D016685:Mitomycin; D009608:Nitrous Acid