Hypervariability, a new phenomenon of genetic instability, related to DNA amplification in Streptomyces ambofaciens.
The wild-type strain Streptomyces ambofaciens DSM 40697 exhibits a high degree of genetic instability. Pigment-defective colonies were observed in the progeny of wild-type colonies at a frequency of about 0.01. While only 13% of these pigment-defective colonies gave rise to homogeneous progeny exhibiting the mutant parental phenotype, 87% of the mutant colonies gave rise to hetergeneous progeny without a preponderant phenotype. This new phenomenon of instability was called hypervariability. In addition, 21% of the mutant strains arising in hypervariable progeny contained highly reiterated DNA sequences, while amplified DNA sequences could be detected in neither stable pigment-defective mutant clones nor in wild-type clones. These results indicate a frequent association between genetic instability and hypervariability and a frequent association between hypervariability and amplification of DNA sequences.
Leblond
P
P
Laboratoire de Génétique et Microbiologie, Faculté des Sciences de l'Université de Nancy I, France.
Demuyter
P
P
Moutier
L
L
Laakel
M
M
Decaris
B
B
Simonet
J M
JM
D004269:DNA, Bacterial / Q000235:genetics*; D005784:Gene Amplification; D005798:Genes, Bacterial; D014644:Genetic Variation; D009154:Mutation; D015183:Restriction Mapping; D013045:Species Specificity; D013302:Streptomyces / Q000235:genetics*
D004269:DNA, Bacterial