[Transmission and exchange of genetic information during bacterial conjugation in ground-based simulations of the factors of orbital flight].

Control laboratory experiments on bacterial conjugation under simulated spaceflight conditions were performed with the use of new equipment (bioreactor RECOMB-2 and container BIOMAGNISTAT) within the RSA-NASA science program. External parameters were selected and the plan of simulation of a space experiment was verified to ensure high efficiency of the conjugative transfer of chromosomal and plasmid DNA and storage of hybrids on the ground. Genetic analysis of conjugative hybrids E.

[Preparation and regeneration of protoplasts from Bacillus megaterium cells dried by sublimation].

Bacterial protoplasts are widely used in genetical research, for instance, in protoplasts fusion experiments and the transfer of heterologous DNA into bacterial cells. The usage of a new fresh grown culture of bacteria in every experiment restricts the reproducibility of the results preventing the technique becoming widespread. The use of antioxidants as components of stabilizing medium for sublimation drying of Bacillus megaterium cells supported cellular viability in bacterial culture.

[Liposomes as a carrier of genetic information].

Incorporation of genetic material into the bilayer lipid vesicles (liposomes) and the subsequent transfer of liposomal content into cells or protoplasts appear to be a promising technique for transfer of genetic information. The following three methods are most frequently used to incorporate DNA into liposomes lipid microinjection into aqueous phase, multistep treatment of the lipid suspension by ultrasonication, Ca2+ ions and EDTA, reverse phase evaporation. Viral particles, chromosomes, nuclei, viral nucleic acids, plasmids and chromosomal DNA can be successfully transferred into animal and plant protoplasts by the described technique.

[Incorporation of plasmid DNA into liposomes from the total lipid of E. coli and determination of their stability].

Large monolamellar liposomes were constructed from the total E. coli lipid by ultrasonication and consecutive treatment with Ca2+ and EDTA. Serum albumin and plasmid DNA were incorporated into the liposomes with the efficiency of 6.

[Changes in RNA biosynthesis in the liver of chicks with coccidiosis].

The RNA fraction and the intensity of their turnover in chick liver during experimental coccidiosis was studied. A marked (about 60%) increase of intensity of mRNA turnover with no changes in its amount was found. It was shown that pre-rRNA biosynthesis was significantly enhanced and, due to it, the amount of both pre-rRNA and mature 18S rRNA was increased while the level of 28S rRNA was unchanged.

[RNA biosynthesis and regulation of protein biosynthesis in the liver of chicks with experimental coccidiosis].

The aim of this work was to investigate the interrelationship between RNA biosynthesis and that of protein in chick liver during experimental coccidiosis induced by E. tenella. The peculiarity of this model is that in the course of this disease protein synthesis is significantly intensified inspite of the fact that the rate of the biosynthesis is rather high under normal conditions.

[Isolation of RNA containing a polyadenylic acid sequence by chromatography on unmodified cellulose].

A new modification of the procedure of the isolation of polyA-containing RNAs is worked out, which makes possible to isolate this RNA fraction free of considerable contamination with rRNA. The administration of 0.0001 M EDTA-Na2 provides the absence of RNA aggregation and prevents non-specific RNA binding on cellulose columns, which takes place when more high EDTA-Na2 concentrations in elution solutions are applied.

[Influence of fast electrons on the nucleic acid level and the biosynthsis of RNA in cells of the ascites tumor NK/Ly and the spleen of tumor-bearing mice].

The results of investigations on total nucleic acids content and RNA turnover in the cells of tumor NK/Ly and of the spleen in tumor-bearing mice after single exposure to fast electrons are described. In every case the irradiation results in reliable changes of parameters under study. The pattern of changes in nucleic acids content and turnover in the spleen after the exposure to fast electrons is in a good agreement with the available data concerning the influence of x- and y-radiation.