[Analysis of reporter gene expression at different segments of the vaccinia virus genome].

Two reporter genes: the firefly Photinus pyralis luciferase gene and the Escherichia coli beta-galactosidase gene were used for construction and characterization of the five unique recombinant vaccinia strain LIVP viruses expressing these genes in three nonessential regions of the virus genome. We give comparative characteristics of beta-galactosidase and luciferase activities in experiments of transient expression and expression dynamics of reporter genes by different stable recombinant viruses. Both genes are expressed with high efficiency independent on the sites of virus genome localization.

Transient expression assay in a baculovirus system using firefly luciferase gene as a reporter.

Transient gene expression assays were developed to assess the function of the regulatory sequences of baculoviruses Bombyx mori nuclear polyhedrosis virus (BmNPV) and Autographa californica nuclear polyhedrosis virus (AcNPV) in insect cells of Bombyx mori and Spodoptera frugiperda, respectively. DNA sequences encoding luciferase (luc) of the firefly Photinus pyralis was successfully employed in the expression assay as a reporter gene. Recombinant plasmids were constructed containing the luc gene under control of baculovirus-specific or heterologous promoters.

[Polymerase and immunologic activity of reverse transcriptase of the HIV-1 virus, isolated from Escherichia coli].

The recombinant reverse transcriptase of HIV-1 virus has been isolated from Escherichia coli cells transformed by the plasmid pRT40 DNA. The 103 Kd protein produced by these cells is shown to be processed to proteins with lower molecular masses by the reverse transcriptases own protease activity as well as Escherichia coli proteases. The resulting 103-66 Kd proteins possess the polymerase activity while 51 Kd and smaller proteins are lacking the activity.

[Expression of the glow worm luciferase gene in mammalian cells using vectors based on vaccinia viruses].

The transient expression of the two reporter genes, the genes for luciferase and bacterial beta-galactosidase, were used for comparative estimation of vaccinia viral promoters and for characterizing of the constructed plasmids. The recombinant clones of vaccinia virus expressing simultaneously and with high efficiency the luciferase and beta-galactosidase were used for studying the reproduction of vaccinia virus in mammalian cells. The advantages of the luciferase gene in using it as a reporter gene are discussed.

[Study of the stability of hybrid plasmids replicating in Saccharomyces cerevisiae due to DNA fragments from polyoma virus].

Hybrid plasmid pSP97 carrying the entire genome of polyoma virus (PY), inserted into bacterial vector psV3, transforms yeast cells with the frequency 1 x 10(-2). Plasmid pSP97 is capable of autonomous replication in S. cerevisiae, while its structure remains unaltered, the stability of hybrid plasmid in transformants is 44%--100%.

Synthesis of proteins coded by plasmid vectors of pCV series (Apr, Tcr) and their recombinant derivatives (pDm) in E. coli minicells.

Polypeptide synthesis directed by vector plasmids of pCV series conferring ampicillin and tetracycline resistance (Apr, Tcr) and by recombinant plasmids (pDm) have been analyzed using the minicell system. It has been found that a polypeptide of 34 000 daltons is responsible for the Tcr phenotype and regulated from the promoter near the HindIII site. Cloning of DNA fragments into HindIII site allowed to conclude that DNA from Drosophila melanogaster contains nucleotide sequences which may act as promoters for a 34 000 dalton polypeptide gene.

Effect of change in structure of cohesive ends on aggregating ability and biological activity of bacteriophage lambda DNA.

The effect of different types of buildup of the cohesive ends on the ability of phage lambda DNA molecules to form cyclic and concatemeric forms and on their biological activity in two infection systems--transfection and transformation--was investigated with the aid of E. coli DNA polymerase. A change in the structure of the cohesive ends leads to a change in the aggregating ability of the phage lambda DNA molecules up to an almost complete loss of this ability.

[Identification of partial hydrolysis products of lambda bacteriophage DNA by restriction endonuclease EcoRI].

The relationship between the electrophoretic mobility of double stranded DNA fragments electrophoresed in agarose gel and their molecular weights within the range from 1.10(6) to 8.10(7) daltons and agarose concentration 0.