Том 43, № 5 (2016)

The aim of this study was to establish the role of oxidative modification of proteins and redox status in the realization of apoptosis of MCF-7 breast adenocarcinoma cells during cultivation with the SH-group blocker N-ethylmaleimide (NEM) and the SH-group protector 1,4-dithioerythritol (DTE). The activation of apoptosis in MCF-7 breast adenocarcinoma cells was shown to be due to the irreversible modification of redox-sensitive protein molecules. The presence of DTE in the culture medium of cancer cells caused reversible glutathionylation of protein molecules and did not change the number of apoptotic MCF-7 cells.

It was found that ants significantly affect the physiological activity and functional diversity of soil microbial communities, and redistribution of biophilic elements (C and N) down through the profile occurs in anthills compared to the control soil, as well as their accumulation in the underground part of the ant nests. A high urease activity was revealed in ant nests and ants. Functional dissimilarities of bacterial communities in all studied objects were determined by the multisubstrate test.

The phylogenetic position of the genera Rossithidium and Psammothidium was studied using the plastid gene rbcL. The genus Rossithidium is not an independent taxon and should be transferred to Psammothidium. Taxa from Psammothidium genus formed a sister, but independent clade to taxa with Achnanthidium. Our data has shown that the order Achnathales was not the natural taxon and should be reduced, but the three families included in it were natural. Genera like Psammothidium (including Rossithidium) and Lemnicola should be included into the family Achnanthidiaceae. Therefore, raphe does not play an important role in diatom taxonomy and its loss occurred many times during the evolution of diatoms.

It was shown that tobacco leaf treatment with 100 mM H₂O₂ increased their content of endogenous H₂O₂ and activities of catalase and hydrolases (acid phosphatase, proteases, and RNase) and also caused various changes in the cell structure. In this case, programmed cell death (PCD) occurred in some cells, which was observed as chromatin condensation, cytoplasm collapse, etc. In the meantime, many cells displayed organelle activation rather than PCD. It is suggested that cells that undergo H₂O₂-dependent PCD release signaling molecules inducing protective mechanisms against oxidative stress in neighboring cells not exhibiting PCD.

Ontogenetic allometry of the cranium was studied in 580 individuals of the Eurasian beavers Castor fiber in two subspecies out of six autochthonous and reintroduced populations using the methods of multivariate nonparametric statistics. It was noted that the growth dynamics demonstrates a correspondence to trajectories of ontogenetic rodent models with the difference that intensive beaver growth finishes by the age of four years. Significant differences in the dynamics of age variability were detected in the beavers of two subspecies; with somewhat smaller initial postnatal sizes, C. fiber belorussicus grows faster than C. fiber orientoeuropaeus.

A study of the effect of a complex probiotic preparation with bacteria of the genus Bacillus and a microdose of larvae of the fly Hermetia illucens on the physiological parameters of fish has been carried out. It was established that introduction of the complex into artificial feeds for tilapia and Russian sturgeon juveniles during their incubation in recirculating aquaculture systems improves the digestion efficiency and increases the rate of fish growth and body mass accumulation. In tilapia, a decrease in the cholesterol level was revealed, while in sturgeon, an increase in the hemoglobin content was found. It was noted that a probiotic with biologically active agents H. illucens had a stimulating effect on the development of sexual gonads in female sturgeon fry, promoted an increase in the ovary mass, and provided for the development of eggs without morphological disturbances.

The composition and functional structure of the intestinal microflora of three wireworm species (Agriotes obscurus (L.), Selatosomus aeneus (L.), and Ampedus pomorum (Herbst)) with different dietary regimes were studied. The total abundance of the microorganisms was evaluated by fluorescent microscopy, the group composition was assessed by inoculation on a solid glucose-peptone-yeast medium, and the functional diversity was estimated by multisubstrate testing. It was noted that, in the intestine of the larvae, the total number of microorganisms was lower by 1–2 orders of magnitude than in the soil and decaying wood. It was found that the composition of the intestinal microbial communities of wireworms was radically different from that of the substrate: the Bray-Curtis coefficient did not exceed 0.25. It was found that native forms accounted for more than half of the total number of saprotrophic bacteria: in the larvae, Gram-positive cocci, enterobacteria, Vibrionaceae, Acinetobacter, and some genera of coryneform bacteria, which were absent in the soil and wood, prevailed. The micromycetes were either absent (Agriotes) or were found in insignificant quantities (Selatosomus, Ampedus). In Selatosomus, apart from the intestinal forms, representatives of Mezorhizobium, Nocardioides, and Erwinia, occurring on plant substrates, were observed.

The relations of different characteristics of soil nematode communities with the type of natural (forest and meadow) biocenoses and the main parameters of assessment of the state of soil ecosystems were determined in the course of monitoring. It was found that the number of nematodes and number of taxa in the fauna are highly variable. It was noted that meadow biocenoses stand apart by the diversity of nematodes and the proportion of plant parasites in the community structure. A significant functional contribution in the distinguishing of the main types of biocenoses was determined only for the index reflecting the organic matter decomposition in the soil using discriminant analysis. It was shown that the complex analysis of the parameters of nematode communities most informatively characterizes the state of the soil ecosystem.