Accession Number : AD0839573

Title :   SOME PECULIARITIES OF THE INDUCED VARIABILITY OF MICROORGANISMS,

Corporate Author : ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER CHARLOTTESVILLE VA

Personal Author(s) : Alikhanyan, S. I.

Report Date : 1968

Pagination or Media Count : 18

Abstract : A continuous utilization of mutagenes for the selection of highly active strains leads to a gradual activity decrease to be accomplished with a complete disappearance of the selection effect. This occurs with and without application of mutagenic factors. Two hypotheses are advanced to interpret the phenomenon of the extinction of the selection effect. According to the first hypothesis, a prolonged utilization of the mutagene results in an accumulation by highly active strains of plus mutations of all the genes controlling the antibiotic synthesis. A further treatment of these genomes with mutagenes increases the number of back mutations, i. e. treatment of active strains with mutagenes results in a more frequent development of minus variants at the expense of back mutations. The hypothesis can be well illustrated by the stable plateau on the selection curve. According to the second hypothesis, a repeated inefficient selection induced by the same mutagene is a result of an accumulation of mutations in the same site acting as a hot point with respect to the mutagene. In other words, a repeatedly applied mutagene involves the same group of genes or sites. (Author)

Descriptors :   *GENETICS), (*MICROORGANISMS, MUTATIONS, GROWTH(PHYSIOLOGY), ANTIBIOTICS, BIOSYNTHESIS, USSR.

Subject Categories : Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE