Identification of toxic Cyanobacteria in Lake Baikal.

Cyanobacteria of the genera Anabaena and Microcystis, containing genes for the synthesis of-microcystins (hepatotoxic cyanotoxins) were found for the first time in the coastal zone of Lake Baikal near-the village of Turka, where a tourism and recreational complex were constructed. According to the enzyme-immunoassay, microcystin concentration in water was 0.17 ± 0.01 µg/L. Using 16S rRNA gene pyrosequencing, we found 3936 sequences in the eubacterial community of central basin of Lake Baikal. The summer bacterioplankton in both littoral and pelagic areas of the lake was dominated by the phylum Cyanobacteria, whereas a higher diversity of cyanobacteria was recorded in the plankton of the littoral zone. Moreover, the-potentially toxic Anabaena and Microcystis were detected in this area.

[Genetic diversity of cyanophages of the Myoviridae family as a constituent of the associated community of the Baikal sponge Lubomirskia baicalensis].

Molecular-genetic analysis of cyanophages of the family Myoviridae from the associated community of the endemic Baikal sponge Lubomirskia baicalensis was carried out based on the g20 gene fragment. A large cyanophage diversity according to the g20 marker gene was found in the sponge. The Baikal sponge cyanophages were shown to be similar to those inhabiting plankton. Moreover, specific cyanophage groups that are significantly different from all of the known groups inhabiting the Lake Baikal were revealed.

[Molecular-and-genetic diversity of cyanophages of the family Myoviridae in Lake Hovsgol (Mongolia)].

Cyanophages of the family Myoviridae were studied in Lake Hovsgol based on the analysis of g20 gene fragments. The analysis revealed the diversity of g20 cyanomyovirus sequences in Lake Hovsgol. It was found a great similarity of genes from the Lake Hovsgol and Lake Baikal. Distribution of closely related virus strains in these water bodies is attributed to close geographical location, direct water connection and similar hydrochemical parameters of the lakes.

[Molecular-genetic comparison of morbilliviruses which caused epizooty in Baikal (Phoca siberica) and Caspian (Phoca caspica) seals]. / Molekuliarno-geneticheskoe sravnenie morbillivirusov, vyzvavshikh épizootii baikal'skikh (Phoca sibirica) i kaspiiskikh (Phoca caspica) tiulenei.

The nucleotide sequences were determined for a phosphoprotein gene fragment of canine distemper virus (CDV) by using the RT-PCR method with the subsequent sequencing of amplicons from total RNA isolated from 2 samples of Caspian seals, 15 samples of Baikal seals and from samples of dog's and sea-lion's brains. The above materials were phylogenetically analyzed. The heterogeneity of the virus circulating in the Baikal-seal population was demonstrated. Morbillivirus, that caused epizooty in Caspian seals, was shown to be a CDV variant, whose phosphoprotein gene structure was not different, within the analyzed stretch, from the corresponding gene of the most widespread variant of the Baikal seal virus. The data obtained suggest that morbillivirus could be transmitted by birds during their seasonal migrations.

[Analysis of genetic variability of strains of tick-borne encephalitis virus by primary structure of a fragment of the membrane protein E gene]. / Analiz geneticheskoi éntsefalita po pervichnoi strukture fragmenta gena belka obolochki E.

Primary structures of gene fragments of E protein (160 n.b.) have been determined for 29 tick-borne encephalitis (TBE) strains isolated from different parts of a territory. Analysis of homology of nucleotide sequences of these strains and data on 6 TBE strains published by other authors showed that they can be divided into 6 groups (genotypes) by the following gene typing criteria: strain structure within the genotypes differing by no more than 9%, differences between strains of different genotypes are at least 12%. Based on these criteria, the prototype strains of the Far Eastern antigenic variant (Sofyin), Central European antigenic variant (Neudoerfle), and Vergina strain form different genotypes 1, 2, and 6, respectively. East Siberian strain Aina and Ural Siberian strain Lesopark-II belong to the same TBE virus genotype 3; two-thirds of analyzed strains belong to this genotype. Genotype 4 is represented by one strain 178-79, and genotype 5 by strain 886-84, both isolated in East Siberia.

[Genetic typing of tick-borne encephalitis virus based on an analysis of the levels of homology of a membrane protein gene fragment]. / Genticheskoe tipirovanie shtammov virusa kleshchevogo éntsefalita na osnove analiza urovnei gomologii fragmenta gena belka obolochki.

All heretofore known genomic structures of tick-borne encephalitis (TBE) virus are analyzed. The authors prove the adequacy of using short fragment of E protein gene for characterization of philogenetic relationships between TBE strains. Three main genotypes of the virus are distinguished, one corresponding to Far Eastern variant, one to West, and the third includes strains belonging to Ural Siberian and Central Siberian and Transbaikal variants. Results of genetic typing by nucleotide sequences are confirmed by analysis of amino acid sequences of E protein fragments, specific marker amino acids in definite positions being determined for each genotype.