[Formation of the heterozygous tandem duplication in the process of conjugation recombination in Escherichia coli: study of the effect of mutations for the recQ, uvrD, and recJ genes].
Stable tandem duplications were shown to originate from conjugational recombination between Escherichia coli HfrH strains carrying mutations for the deo operon. The duplications deoC deoD/deoA deoB::Tn5 usually constitute approximately 5% of the Deo+ offspring. The effect of mutations for the recQ, uvrD, and recJ genes on the frequency of duplications was studied. The CM1563 strain carrying the recQ mutation was shown to give, as a recipient, 20% of duplications in the Deo+ offspring. However, this property of CM1563 seems to depend on the presence of a spontaneous mutation of unknown nature, which also increased UV sensitivity of bacteria. The recQ mutation itself increased the frequency of duplications by less than 50%. The recJ mutation did not virtually affect the frequency of duplications. The uvrD mutation possessing the recombinogenic effect was shown to increase the frequency of deo+ recombinants and simultaneously decrease the frequency of duplications. Tandem duplications are assumed to be normal intermediates of multi-stage conjugational recombination initiated by the integration of the proximal region of the Hfr chromosome into different nonhomologous regions of the recipient chromosome.
State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, Russia.
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Sukhodolets
D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005819:Genetic Markers; D006579:Heterozygote; D009154:Mutation; D009876:Operon; D020080:Tandem Repeat Sequences
D005819:Genetic Markers
Obrazovanie geterozigotnykh tandemnykh duplikatsiĭ v protsesse kon"iugatsionnoĭ rekombinatsii u Escherichia coli: izuchenie éffekta mutatsiĭ po genam recQ, uvrD, recJ.