[Phenol biodegradation by a Pseudomonas sp. strain tagged with the gfp gene].

Conjugal transfer of the pAG408 suicide vector from E. coli S 17.1 to Pseudomonas sp. cells able to consume phenol yielded transconjugates brightly luminescing under UV illumination. It was shown that tagging of the Pseudomonas sp. cells with the gfp gene did not affect their ability to consume phenol. The change of the population density of the tagged bacteria after their introduction to soil was studied. The potential of the resulting bacterial strain in remediation of phenol-polluted soils is discussed.

Transfection of insect cell lines using polyethylenimine.

Insect cell lines have been widely used in recombinant baculovirus expression systems and transient gene expression studies. Critical to these applications have been the transfection of foreign DNA. This has been frequently done using labor intensive and cytotoxic liposome-based transfection reagents. In the current study we have optimized a new kind of polyethylenimine-based DNA transfection reagent on the Spodoptera frugiperda Sf9 insect cell line. A plasmid vector that transiently expresses green fluorescent protein (GFP) was effectively delivered into Sf9 cells. A transfection efficiency of 54% and cell viability of 85-90% were obtained for Sf9 cells. The developed transfection protocol has now been successfully used to transfect eight insect cell lines derived from Bombyx mori, Trichoplusia ni, Helicoverpa zea, Heliothis virescens and S. frugiperda with GFP and GUS with transfection efficiencies of at least 45%. This method provides high heterologous protein expression levels, transfection efficacy and cell viability, and could be used for transient gene expression in other lepidopteran cell lines.

[Microorganisms--degraders of polychlorinated biphenyls]. / Mikroorganzimy--destruktory polikhlorirovannykh bifenilov.

Four strains belonging to the genus Bacillus, capable of degrading polychlorinated biphenyls (PCB), were isolated by screening the collection strains of soil bacteria, degrading a organochlorine pesticide, hexachlorocyclohexane (HCCH). A method for production of tritium-labeled PCB was developed. Consumption and degradation of PCB by the soil bacterial strains selected were studied using tritium-labeled PCB and GLC. It was demonstrated that PCB are degradable both in culture media and under in model soil samples.

[Nucleotide sequence of internal transcribed spacers and 5.8S rDNA for the ribosomal operon from alfalfa Medicago sativa and cotton Gossypium hirsutum L]. / Nukleotidnye posledovatel'nosti vnutrennikh transkribiruemykh speiserov i 5.8S rDNA ribosomnogo operona u liutserny Medicago sativa i khlopchatnika Gossypium hirsutum L.

The 708- and 769-bp fragments from alfalfa and cotton containing the 3'-end of the 18S gene, the internal transcribed spacer. 1 (ITS1) the 5.8S gene, ITS2, and the 5'-end of the 28S gene were obtained using primers to the 18S and 28S ends of rDNA from tomato by a polymerase chain reaction. These sequences were cloned into pTZ19R. The 5.8S rDNA, ITS1 and ITS2 nucleotide sequences of alfalfa and cotton were determined. Comparative analysis of nucleotide sequences of alfalfa and cotton showed large hypervariability of spacer regions and conservatism of 5.8S rDNA sequence.

[Cloning a species-specific DNA probe from Fusarium oxysporum fungus]. / Klonirovanie rodospetsificheskogo DNK-zonda iz griba Fusarium oxysporum.

A method to obtain genus-specific DNA probes is suggested. It consists of specific amplification of the intergenic spacer between the 18S and 5.8S ribosomal RNA genes, using primers deduced from conservative ribosomal DNA sequences. The utility of the method is demonstrated on isolation of the 209 b.p. spacer fragment from the genomic DNA of a plant pathogenic fungus Fusarium oxysporum.

[Organization of genes of ribosomal RNA from the mushroom Verticillium dahliae]. / Organizatsiia genov ribosomnykh RNK griba Verticillum dahliae.

Using yeast probe, a complete ribosomal DNA unit from a plant pathogenic fungus, Verticillium dahliae, was cloned into a plasmid vector pTZ19R. Partial DNA sequence of the clones, when compared to the yeast ribosomal DNA sequence, allowed to establish the physical map of the fungal rDNA. The overall organization was shown to be similar to other fungal rDNAs previously known.

[Effect of thyroid hormone receptors in normal and cancerous cells on the ionic conductivity of bilayer phospholipid membranes]. / Vliianie retseptorov tireoidnykh gormonov normal'nykh i rakovykh kletok na ionnuiu provodimost' bisloinykh fosfolipidnykh membran.

The effect of thyroid hormones receptors isolated from normal and cancer cells on bilayer phospholipid membranes (BPhLM) conductivity, has been studied. The receptor isolated from normal cells in complex X with the hormone selectively induces H+-conductivity of BPhLM generating transmembrane potential equal to 42 mV on the membrane at pH gradient equal to 1. In the presence of K+, Na+, Ca+, Mn2+, Sr2+, Mg2+ the changes of BPhLM are not observed. Neither hormones (T3, T4) nor receptor in free position affect the BPhLM conductivity. Thyroid hormone receptor isolated from mamalignantly transformed cells in a complex with T3 or T4 increases the BPhLM permeability for Ca2+. The transmembrane potential measured at 10fold Ca2+ ion concentration is equal to 16 mV. In the presence of H+, K+, Na+, Mn2+, Sr2+, Mg2+, Ba2+, the resistance of BPhLM doesn't change.