In this work, we investigated the chromatosome stability under the influence of oncomutations and post-translational modifications. A chromatosome is formed during the interaction of a nucleosome with linker histone. This interaction may be characterized by the binding free energy. We hypothesized that oncomutations may be associated with changing of the binding free energy and subsequent changes in chromatin compaction state and gene expression levels. Calculations of the binding free energy were performed using the FoldX program algorithms. Screening of the positions of post-translational modifications for potential steric constraints was also performed. The analysis of the data allowed us to identify the oncomutations and post-translational modifications, which can significantly change the binding free energy of the linker histone with the nucleosome, thereby, possibly, affecting the structure of chromatin.

Leaf anatomical characteristics are considered as important diagnostic features for identifying grasses. Cross sections in the middle part of the leaf blades have been traditionally used for such purposes. The leaf anatomy has been of key interest in diagnostics of fescues Festuca L. because of great morphological similarity between the species, particular attention is paid to the arrangement of sclerenchyma in the middle part of the leaf blades of fescues.  The lack of knowledge regarding the spatial distribution of tissue throughout the leaf blades of grasses does not allow to evaluate the diagnostic significance of data obtained from the single two-dimensional cross section. The aim of the work is to make 3D models of sclerenchyma from serial sections of leaf blades of two narrow-leaved fescues Festuca valesiaca Gaud. and Festuca beckeri (Hack.) Trautv. We also attempted to find out the quantitative patterns of the distribution of sclerenchyma along the leaf blades of F. beckeri and F. valesiaca. Cross-sectional areas of sclerenchyma increase just above the blade/ sheath junction and then gradually decrease up to tips of the leaf blades in both species. Subepidermal sclerenchyma of the fescues arranges in uneven layer. The layer of F. beckeri is more or less solid, the layer of F. valesiaca is dissected by four long splits. Changes in the shape of sclerenchyma sections along the leaf blades are more pronounced in F. valesiaca than in F. beckeri. Variability of the sclerenchyma arrangements along the leaf blades should be considered when using 2D sections of the leaf for diagnostics of fescues.

Embryos and larvae of many amphibian species are widely used as experimental models in the areas of developmental biology, toxicology and fundamental medicine. However, there are almost no experimental approaches considering the biology of particular species. Moreover, experimental conditions are not standardized between different laboratories, and there are no examples of making efforts to minimize an influence of the researcher’s personality on the results of experiments. The worse thing is that many experimental methods designed for particular species are applied for other amphibians without an adaptation. In the presented paper, the results of long-term experimental investigations of environmental factors influencing embryonic development of the common toad Bufo bufo are summarized. These investigations are an example of establishing the methods and approaches considering the species biology, allowing minimizing heterogeneity of an influence of stochastic factors and standardizing experimental conditions. For this species, it is recommended to maintain the temperature at 15°C in the course of all experiments, to perform all measurements with 8 hr intervals, and to perform each test in at least two replicas, which differ in the initial density of embryos (clutch fragments containing 30 or 120 embryos per standardized aquarium). When designing experiments, it is suggested to consider not only volumetric density of embryos (the number of embryos per unit of volume), but also their surface density (the number per unit of area) and linear density (the number per unit of roe cord length). It was experimentally shown that it is necessary to keep the interactions between the researcher and the object at a minimal level, as all kinds of researcher actions, including removal of death embryos, severely affect the results of experiments.

We aimed to research the spectrum of the CSR strategies for subalpine tallgrass communities of the Northwest Caucasus (Teberda state natural biosphere reserve). The community is typical of the subalpine zone in the altitude range of 1850 to 2600 m (mean 2300 m). It occupies the lower portions of slopes, valley bottoms and depressions on slopes with significant winter snowpack accumulation. Stable water supply from the upper part of slopes is an important factor increasing its productivity. A few tall and highly productive species have established at such sites, since grazing was stopped. The community dominants are Rumex alpinus, Senecio platyphylloides, Cephalaria gigantea, Ligusticum alatum and other. Accomplish this we measured key functional traits of the leaves: leaf area, wet leaf mass, dry leaf mass. On the basis of these traits we calculated CSR-strategies for the 42 species of the tallgrass communities. We defined six types of CSR-strategies and confirmed that most of explored species has strongly pronounced traits of the competitive (C) and competitive-ruderal (CR) strategies. For the 11 species C-strategy was identified (for example, Angelica purpurascens, A. tatianae, Cirsium chlorocomos, Heracleum asperum, H. leskovii, H. sosnowskyi). The degree of C-selection has positive correlation with mean height of the species. CR-strategy was shown for the Aconitum nasutum, Cirsium simplex, Geranium sylvaticum, Hesperis voronovii, Rumex alpestris and other. Two species (Achillea millefolium, Dactylis glomerata) have competitive-stress-tolerant strategy (CS). Stress- tolerant (S) strategy has been identified for the three species Veronica filiformis, Lilium monadelphum, Millium effusum. Two species have CSR-strategy (Trifolium pratense, Astrantia maxima). Also, 70% species have the ruderal strategy features (on average, 26%). We assume it is result of the anthropogenic influence for many centuries. Our results contradict the popular point of view that highland species have stress-tolerant strategy. This can be explained by the ecological conditions in the lower portions of slopes, valley bottoms and depressions on slopes. In this conditions competitive species are most adaptive. Our hypotheses was supported; constant Caucasus species of the subalpine grass communities have significantly racteristics of competitive strategies (up to 95%) (except V. filiformis).

 

 

Damage to the plasma membrane (PM) of cells in pea leaf epidermis, determined by its permeability to propidium iodide  (PI),  which  binds  to  DNA  of  cell  nuclei, and programmed cell death (PCD) detected by the destruction of cell nuclei was investigated. PM of the epidermal cells in the isolated epidermis was permeable to PI (it stained their nuclei). PM of the guard cells did not allow PI to pass through. KCN, an inducer of PCD, caused the destruction of the both epidermal and guard cell nuclei. KCN-Induced destruction of guard cell nuclei was accompanied by the penetration of PI into the cells. The polycation chitosan at a concentration of 0.1 mg/ ml caused the destruction of the epidermal cell nuclei, but at a concentration of 1 mg/ ml, the permeability of the guard cell PM for PI staining their nuclei was induced. Other polycations (cytochrome c, polylysine, polyethylenimine and protamine) also caused staining of the guard cell nuclei by PI. Polyanions (polyacrylic acid, dextran and heparin) initiated the destruction  of  cell  nuclei,  which  was  accompanied  by the penetration of PI into cells. Detergents Triton X-100 and lauryldimethylamine- N-oxide produced the permeability of the guard cell PM for PI and prevented the destruction of the nuclei that was induced by  KCN.  Treatment  of  the  epidermis with Triton X-100 (for 2 h with its subsequent washing) increased the destruction of the guard cell nuclei that  was  caused  by  KCN.  Polycations  polyethyleneimine and protamine were prevented, while  chitosan,  cytochrome  c,  and  polylysine,  on the contrary, enhanced KCN-induced destruction of the guard cell nuclei. The data obtained shows that the destruction of cell nuclei upon induction of cell death with KCN or polyanions is accompanied  by  damage  to  PM  (producing  its  permeability for PI). Damage to PM caused by detergents or polycations prior to cell treatm       by KCN, can prevent or, on the contrary, intensify the destruction of cell nuclei.

The 2,4,5-Trichlorophenoxyacetic acid   (2,4,5-T)-degrading strain Bacillus mobilis 34Т isolated from the soil sample of the largest producer of herbicides in Russia was described. The strain was identified as Bacillus mobilis 34Т according to the cultural, morphological, morphometric, physiological, biochemical, features as well as the results of the comparative analysis of the 16S rRNA gene sequence. The growth of B. mobilis 34Т in the batch culture with using 2,4,5-T as a sole source of carbon and energy was studied. It was showed that 2,4,5-T content was reduced from the initial level by 29% and 62% during the first and ninth day, respectively. The strain was used for the treatment of a soil contaminated with 2,4,5-T. The decontamination degree was 41%, 52%, 58% on the 5th, 10th and 15–20st days of cultivation, respectively.

DP-ribose)polymerase 1 (PARP1) is involved in the processes of DNA repair, replication, transcription, cell cycle regulation and apoptosis. Participation of PARP 1 in DNA repair is determined by the ability of the enzyme to interact with various defects and non-canonical structures of DNA with consequent polyADP- ribosylation of neighboring proteins. Earlier for mononucleosomes containing  a DNA end recapitulating double-strand DNA break near the nucleosome, we found that PARP1 induces nucleosome structural changes in the absence of NAD+. In the present work we report that PARP1 induces similar structural changes in nucleosomes containing either DNA ends extending from the core by 20 b.p. or containing hairpins at the DNA ends. In all the cases PARP1 caused changes in DNA wrapping on the surface of the histone octamer that are accompanied by an increase in the distance between adjacent DNA gyres. These PARP1-mediated changes in the nucleosome structure presumably contribute to  chromatin decondensation and facilitate access of repair enzymes to damaged DNA.

Partial uncoupling of processes of oxidative phosphorylation and energy storage in the form of ATP («mild» uncoupling) helps reduce the production of reactive oxygen species and can also mimic the effect of calorie restriction. A number of studies have shown that uncouplers like 2,4-dinitrophenol (DNF) affect the lifespan of Drosophila, yeast, mice and rats, as well as the manifestation of «age-related» changes in replicative senescence mammalian and human cell cultures. This paper is devoted to studying the effect of DNF on the growth and death of «stationary phase aging» Chinese hamster cells. Using the method for determining the colony-forming efficiency of cells, the maximum permissible concentration was selected, 5•10-5 M, in which the substance potentially contributes to the manifestation of the effect of «mild» uncoupling and does not inhibit cell proliferation. At higher concentrations, DNP has a cytotoxic effect for the studied cell culture. Under the influence of DNP, the kinetics of cell growth and cell death does not change in the potentially «mild» uncoupling concentration (5.6•10-7 M), the lifespan of the cell culture does not increase. A similar effect may be due to the type of cells studied. In addition, there is a probability that the opt  l concentration lies in the range from 5•10-7 to 5•10-5 M, or lower than 5•10-7 M.

The bioelectric properties of various forming parts of the heart undergo significant changes during pre- and postnatal ontogenesis. Nevertheless, the early stages of embryogenesis determine not only the general scheme of the structure of the heart, but also the features of bioelectric activity in various parts of the mature heart. In particular, the presence of a myocardium with is similar to pacemaker was shown by histological methods in the interatrial septum (AS) of the mammalian heart. However, the electrical activity in this structure remains unexplored. The purpose of this work was to study the ability of AS to generate spontaneous action potentials (AP), as well as to study the effects of adrenergic effects on the bioelectric activity of heart AS. For this, the resting potential and AP were recorded using standard microelectrode techniques in multicellular perfused isolated AS and left atrium preparations obtained from the rat heart at the end of the first day of postnatal development, as well as on the 60th day of life. In our work, α1-adrenomimetic phenylephrine (PE affected the configuration of AP in both AS and atrial tissue obtained from animals of both age groups. In addition, in dormant preparations, PE caused spontaneous activity in AS, but not in atrium, which may be due to fluctuations in the level of cytoplasmic calcium. With the application of a blocker current, activated by hyperpolarization (If), ZD7288 against the background of PE, showed us a decrease in the rate of slow diastolic depolarization of AP in AS - pacemaker cells, a decrease in frequency and the appearance of burst activity, up to complete suppression of AP generation. Thus, the myocardium of the AS in newborn rats generates spontaneous electrical activity in the absence of adrenergic stimulation, which in adult rats is a necessary condition for the appearance of the AS-pacemaker activity. The ability for spontaneous activity is highly – likely to be associated with the presence of pacemaker current If in cardiomyocytes of AS.

The features of species, spatial and trophic structure of macrobenthic sublittoral communities in two coastal lagoon ecosystems of the White sea are studied. Ermolinskaya and Nikolskaya Lips belong to the heavily silted lagoons with simplified trophic community structure of macrobenthos and the predominance of collecting detritus feeders. In sublittoral of lagoons studied were found 24 species of invertebrates, as well as 4 types of sea grasses and algae (Zostera marina, Cladophora sericea, Fucus vesiculosus and Chorda tomentosa). The lagoon ecosystem of Ermolinskaya Lip is characterized by the highest species diversity, total density and biomass of macrobenthos, and the lower indicators – the ecosystem of Nikolskaya Lip. In the lagoon of Nikolskaya Lip, better protected from sea waves and currents, there was a greater development of littoral eurygaline marine and brackish species of macrobenthos, and in the lagoon of Ermolinskaya Lip, less fenced off from the sea, more marine sublittoral species were found.

18 healthy volunteers were involved and the effect of functional neuromuscular electrical stimulation, which causes flexion of the hand, on the corticospinal excitability during motor imagery and resting state was investigated in this study. It was shown that the combined action of functional electrical stimulation and the kinesthetic representation of movements leads to an increase in the amplitudes of motor evoked potentilals, caused by a single-pulse transcranial magnetic stimulation. At the same time, in the state of motor rest this effect was not obtained. Since a change in corticospinal excitability at the cortical level may affect the processes of plastic reorganization necessary for the restoration of motor functions after strokes and other neurotraumas, the results of this work have a direct practical potential. In particular, the possibility of creating effective training complexes for the restoration of motor functions based on brain-computer interfaces, based on the presentation of movements with functional neuromuscular stimulation as a sensor-motor feedback, is discussed. Rehabilitation with the use of such training complexes will help to shed light on the mechanisms of motor recovery, which are based on the phenomena of neuroplasticity, due to changes in the level of excitability of the neurons of the sensorimotor cortex.