Izvestiâ Akademii nauk. Rossijskaâ akademiâ nauk. Seriâ biologičeskaâ

The phylogenies of the plague microbe (Yersinia pestis), reconstructed on the basis of an advanced molecular genetic (MG) approach, are not congruent with the facts accumulated by classical scientific areas: ecology, biogeography, paleontology, epizootiology, and others. The MG approach cannot name the original host of the plague pathogen and reliably characterize the root of the phylogenetic tree. This deficiency is compensated by the ecologic in a broad sense (ECO) approach, which operates with such ecological, phylogeographic and biogeographic categories as geographical population, subspecies, range, ecological niche, direct kinship. Y. pestis, the “blood dweller” of warm-blooded rodent hosts, is transmitted through flea bites and is unique in the family of predominantly intestinal bacteria Yersiniaceae (Enterobacteriaceae). According to the ECO approach, its uniqueness is associated with the origin in the populations of its primary host – Mongolian marmot (Marmota sibirica) in unique circumstances – when the marmot population was infected with pseudotuberculosis not by the traditional alimentary way in grasslands, but in a traumatic way during hibernation. The identification of the original host of the plague pathogen opens up broad prospects for studying its evolutionary history (speciation and intraspecific diversification) and improving the methodology of ecologic, geographic, phylogeographic and phylogenetic studies of this especially dangerous pathogen.

The relative gene expression of enzymes – desaturases and elongases (fadsd5, fadsd6, elovl2, elovl5a, elovl4), which play a key role in the biosynthesis of long-chain polyunsaturated fatty acids, was studied in the liver of juvenile Atlantic salmon Salmo salar Linnaeus, 1758, reared under different lighting and feeding regimes in aquaculture conditions. The expression level of the fadsd5 desaturase gene was higher in Atlantic salmon smolts (0+), reared under round-the-clock lighting and feeding regime, compared to smolts from experimental group with natural photoperiod and daylight feeding. Changes in the level of gene expression (elovl2, elovl5a, fadsd5) in juvenile Salmo salar reflect adaptive processes at the molecular genetic level during the growth and development of fish and in response to changes in environmental conditions. The obtained results make it possible to assess the ability/requirement to the biosynthesis of PUFAs in juvenile salmon during its growth and development.

This paper presents the results of the analysis of mutations such as G:C>T:A, G:C>A:T and G:C>C:G in the TP53 gene in peripheral blood cells in women affected by chronic radiation exposure with breast cancer (24 persons) and without breast cancer (17 persons). 17 different variants representing single nucleotide substitutions were registered. The differences in the frequencies of carriers of the detected variants between the comparison and the main group were not statistically significant. All detected variants were present in the IARC TP53 database and had no clinical significance as “pathogenic.” Despite the absence of statistically significant differences, the question of the effect of chronic low dose rate exposure on the frequency of mutations in the TP53 gene remains open and requires further research involving a greater amount of data.

Data on the new localities of Lemna minor, L. trisulca, and hybrid between L. minor and L. turionifera (L. × japonica) (Lemnaceae) in the north-west of the Murmansk Region (north of 68.5° N), i.e., in the Pasvik State Nature Reserve and neighboring territories in the drainage basin of the Paz River, are presented. Lemna minor and L. trisulca were previously known for the region by several reports. In the north-west of the Murmansk Region, 2 new localities of Lemna minor, 1 locality of L. × japonica, and 10 localities of L. trisulca were found. In total, representatives of Lemna occurred in 18 studied sites: L. minor in 2, L. × japonica in 2, and L. trisulca in 16 (L. minor and L. trisulca grew together in 2 sites). In the studied rivers and lakes, the pH range of water varied from 6.0 to 7.6, i.e., was mainly neutral (the average value was 6.9). TDS varied in the range from 17 to 251 ppm (on average, 53 ppm). The localities of L. minor in the unnamed lake near Zapolyarnyi town and in Kuetsjarvi Lake are probably the northernmost in the world, while locality of L. trisulca in the Paz River in Klistervatn Lake is the northernmost in European Russia. In the north of the Murmansk Region, L. minor and L. × japonica were associated only with anthropogenic eutrophicated water bodies with increased TDS in comparison to the background value. These taxa can be considered an indicator of high trophicity in this region. The localities of L. trisulca are mainly anthropogenic transformed water bodies. The maximum abundance of this species is also recorded in the areas of increased trophic level.

It has been shown that the studied variants of bread wheat plants are resistant to zinc deficiency in substrate. Various ways of adaptation to these conditions by the antioxidant system have been discovered in plants that have a functional allele of the GPC-B1 gene. Thus, in plants of line 15-7-1, the maintain of the redox balance of cells is associated with an increase in the expression of the Cu/ZnSOD gene and a decrease in the expression of the FeSOD and CAT1 genes, whereas in plants of line 13-3, in addition to an increase in the transcripts content of the Cu/ZnSOD gene, with a high constitutive activity of superoxide dismutase (SOD) and catalase (CAT). The data obtained can be used to create wheat varieties (lines) capable of producing seeds with a relatively high content of zinc under zinc deficiency in the soil.

In the present work, the influence of water temperature on the size-age structure and size of the population of Hydrobia acuta molluscs and their invasion with parthenites of the microphallid trematode Gynaecotyla adunca in Kazachya Bay (Black Sea) was studied. A positive correlation between the indicators of invasion extensity and the size, abundance of molluscs and water temperature was revealed. It was found that the seasonal dynamics of G. adunca parthenites abundance clearly distinguishes the periods of mass infesction of molluscs, which are graphically displayed by two peaks – in July and November. It was confirmed that the life cycle of the Black Sea molluscs Hydrobia acuta proceeds similarly to that of Mediterranean individuals

For the first time, two-year seasonal studies of phytoplankton production were carried out in the rocky-sandy littoral zone of the northern deep and cold-water Lake Onego. The research results showed that photosynthesis is characterized by two or three seasonal maxima, the values of which are within the limits of oligotrophic ecosystems. The main primary producers, the concentration of phosphorus in water, and water temperature during the growing season are considered. Differences in the seasonal dynamics of photosynthesis and a similar level of seasonal average and maximum values were revealed in comparison with the deep-water region of the lake. The small contribution of littoral phytoplankton production to the primary productivity of the ecosystem is shown.

The growing impact of human activities on the biosphere requires research into the effects of exposure to hazardous toxic substances on aquatic ecosystems. Ecophysiological parameters of the amphipod Gammarus oceanicus Segerstråle, 1947, such as rates of food consumption, oxygen consumption and phosphate excretion (excreted in the body’s urine), were studied in order to determine the responses of these crustaceans to the influence of a little-studied micropollutant of anthropogenic origin, xenoextrogen, 4-tert-octylphenol (4t-OP). After 28 days of exposure to the lowest concentrations of 4t-OP (0.25 μg/l), a decrease in the feeding and excretory activity of crustaceans was detected, and the level of oxygen consumption was similar to the values in control individuals. All studied parameters of the tested animals changed significantly after the same time of exposure to 2.5 μg/l 4t-OP, showing an adverse effect on the functioning of the crustacean organism. The data obtained can be used to develop criteria for the quality control of the aquatic environment.

We studied the content of immunocompetent blood cells, phagocytic activity of neutrophils, concentrations of cytokines, circulating immune complexes and levels of cyclic nucleotides (cAMP and cGMP) of serum with different levels of soluble adhesion molecules NCAM (CD56) and immunoglobulin Fc-receptor III (CD16) in practically healthy people living in the Arctic territory. It was found that the increase in serum concentration of sCD56 and sCD16 in practically healthy adults of working age is associated with an increase in the content of cells with the corresponding membrane receptors. The increase in sCD56 concentration occurs with an increase in the content of NK cells (CD3-CD16+CD56+) and T-NK cells (CD3+CD16+CD56+). The increase in sCD16 level is accompanied by a decrease in the content of circulating in the blood lymphocytes predominantly T-helper cells (CD3+CD4+), cytotoxic T-lymphocytes (CD3+CD8+) and activated T-lymphocytes (CD3+HLADR+). Increased sCD56 concentrations were associated with increases in pro-inflammatory IL-1β, IL-6, TNF-α and anti-inflammatory IL-10. Concentrations of circulating immune complexes increased with increasing sCD16 and sCD56 content. The signal conduction activity increases with increasing content of CD16+ and CD56+ leukocytes of peripheral blood and sCD56+ leukocytes and shedding of these molecules occurs against the background of decreasing concentrations of cAMP and cGMP.