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B F Iarovoĭ

Publications and source records attributed to B F Iarovoĭ.

10 recordsLinked to original sources
PubMed2001

[Lysine overproduction mutations in the yeast Saccharomyces cerevisiae and its transfection into industrial Yeast strains ].

Yeast mutants resistant to a toxic lysine analog, thialysine were obtained by a method described in the literature. A strain excreting the maximum amount of lysine (0.45 g/l) was selected from these mutants. The intracellular content of lysine was also increased by 30%. The genetic nature of lysine overproduction was studied in this strain. An increase in the amount of excreted lysine was shown to be determined by at least two genes, one of which carries a mutation of thialysine resistance manifesting the pleiotropic effect of lysine overproduction (Th1R) and the other is involved in the regulation of lysine production (PRL). Linkage groups of these genes were determined: the first gene was mapped to the IV chromosome and the second, to the XV chromosome. Both genetic characters were introduced into industrial baker's yeast strains via a series of backcrosses. The stabilization of the genome in the newly derived strains was confirmed by electrokaryotyping.

Chromosome Mapping↗
PubMed1991

[Rearrangements of yeast chromosomes revealed by pulsed field gel electrophoresis].

Electrophoretic karyotypes of yeast Saccharomyces cerevisiae integrant strains containing the pYF91 plasmid integrated into the chromosomes I, III, VI, IX, XI were studied. A possibility was demonstrated of visual identification of the chimaeric chromosomes via the molecular weight increase by 13200 bp (the plasmid size) determined by pulsed field gel electrophoresis. Several gamma-rays induced rearrangements of the yeast chimaeric chromosome I causing instability in hybrids were also studied. The deletions induced in the I chromosome were analysed and their size estimated. The technique of pulsed field gel electrophoresis is recommended for determination of insertions and deletions in the chromosomes of yeast Saccharomyces cerevisiae.

Chromosome Deletion↗
PubMed1990

[Chromosome polymorphism in the yeast Saccharomyces].

The variability of chromosomal band patterns was determined by pulse electrophoresis. The natural strains differed by the quantity and electrophoretic mobility of chromosomal DNA bands. The strains of independent genetic stocks originated from the XII race of Saccharomyces cerevisiae showed less significant difference in band patterns than the strains of different species of the Saccharomyces genus. The progeny of among strains with different karyotypes hybrid showed non-regular segregation of parental bands, the occurrence of new bands and the bands with altered mobility. Reverse crosses of hybrid progeny with strains of Peterhoff genetic stocks of S. cerevisiae led to decrease in chromosomal polymorphism. Homozygotization for ski5 allele and selection for increasing the copy number of killer plasmids was accompanied with repeated splash of polymorphism in 1-2 generations of intratetrad and intrafamily crossed hybrid progeny. Subsequent stabilization of electrophoretic karyotype took place, excluding the mendelian dimorphism of chromosome III, with was a stable trait of the last 6 generations of that progeny.

Chromosomes, Fungal↗
PubMed1987

[Radiation-induced instability of yeast chimeric chromosomes].

Instability of the I chimeric chromosome of the yeast Saccharomyces induced by gamma-irradiation has been studied. The chimeric chromosome analysed contained an integrated pYF91 plasmid. Cells of the integrant were irradiated and then mated with non-irradiated cells of the proper tester strain marked by ade1 mutation (red colour of colonies). We isolated 10 hybrids with pink colonies on selective medium. They displayed high degree of mitotic instability during growth on nonselective medium, segregating red colonies (15 to 90% of the total). Tetrad analysis showed that some of the unstable chromosomes exhibited lethal effect in haploids, while others were viable and could pass through meiosis retaining their instability.

Chimera↗
PubMed1987

[Genetic study of plasmid integration into yeast chromosomes. V. Mapping of integration sites for the plasmid pYF91].

The data on mapping the episomal plasmid integration sites in yeast chromosomes I, III, IV, V, VII, XV are presented. In addition to the integration site at leu2 of chromosome III localized earlier, 6 more loci containing apparently the homologous yeast transposons, with a copy in a plasmid, were defined. The fact of plasmid integration was proved by colony hybridization technique with the pBR322 probe. The plasmid DNA segregation (the ratio 2:2) and its linkage to pLEU2 plasmid marker gene were observed in hybrids of all integrants studied.

Chromosome Mapping↗
PubMed1987

[Genetic study of plasmid integration into yeast chromosomes. IV. Integration of the plasmid pYF91 into different yeast chromosomes].

Integration of the episomic chimeric plasmid pYF91 into yeast chromosomes has been studied. Plasmid insertion into the chromosomes was observed to occur with the frequency of 4 X 10(-8). 379 integrants were selected from the highly unstable (cir0) transformants. The fact of plasmid integration into particular chromosomes was confirmed for 318 integrants. Genetic analysis showed that the plasmid can integrate into the region of LEU2 gene or into another arm of chromosome III (227 integrants), and also into other chromosomes: I, II, IV, V, VI, VII, VIII, IX, XII, XV (91 integrants). It is suggested that integration is the result of recombination between yeast chromosomes and homologous plasmid regions carrying LEU2 gene or Ty element and "delta" sequence.

DNA, Fungal↗
PubMedDate not supplied

[Isolation and investigation of natural yeast strains resistant to heavy metal salts and radionuclides].

The collection of yeasts (more than 2000 strains) from extreme natural environment of Kamchatka peninsular and Kuril Islands was created. 448 strains were selected for their resistance to salts of such heavy metals as Cu, Cd, Co and to high temperature (37-52 degrees C). 72% of strains appeared to be resistant to one or more selective factors. We obtained several strains able to grow on medium with 0.1 M/L nonradioactive strontium and (or) cesium. Four of this strains accumulated radioactive isotope 90Sr with 45-80% efficiency. Thus, we demonstrated that yeast strains from nature could be used for bioremediation of industrial waste solutions, polluted by radionuclides and salts of heavy metals.

Drug Resistance, Microbial↗