[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.
Sukhodolets
V V
VV
State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, Russia.
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.