[Inhibition of RNA synthesis in vitro by antibodies against mononucleotides].

Antibodies against purine nucleotides were obtained from rabbits immunized with conjugates of bovine serum albumine with AMP or GMP. The antibodies purified by affinity chromatography on nucleoside monophosphate-human serum albumine-Sepharose columns inhibited RNA synthesis on native T4 phage DNA by E. coli RNA polymerase.

[Effect of plasmid F'Col+trp+ on the transfer of plasmid RP4].

Interaction of conjugative plasmids F'colV colB trp and PR4 in Escherichia coli host was studied during the transfer of the plasmids from cell to cell. The plasmid F'colV colB trp is found to stimulate the transfer of RP4 from the diplasmid strain. This seems to be due to stabilization of the conjugating pairs which require normal pili coded by the plasmid F'colV colB trp.

[Expression of the gene for tetracycline resistance of plasmids R6 and RP4 in bacteria of the family Enterobacteriaceae].

It was found that manifestation of the tetracycline resistance gene depended on the type of the plasmid containing the gene. The tetracycline resistance gene was subject to less repression in plasmid R6 than in plasmid RP4. Sensitivity of the initial plasmid-free bacteria varied within lower dose ranges than that of the plasmid-carrying strains.

[Transmission of plasmid Rldrd19 from E. coli to Hafnia].

Investigations carried out demonstrated a possibility of transmission of plasmid Rldrd19 from E. coli to Hafnia. The incidence of the plasmid transmission varied from 10(-7) to 10(-9) and depended on the properfies of Hafnia strains.

[Immunogenic DNA of Shigella sonnei bacteriophage].

Immunogenic and some other properties of Sh, sonnei "Ufa" phage DNA were investigated. This DNA has been shown to possess high immunogenic activity indicating the presence of an unusual base. The base is distinct from 5-OmC, glucosylated 5-OmC, 5-OmU or dihydroxypentyluracil.