Том 515, № 1 (2024)

Significant differences in the fatty acid composition of the muscle tissue of juvenile Arctic char Salvelinus alpinus [Linnaeus, 1758] from the natural habitat (Lake Sobachye) and aquaculture, as well as juveniles of the anadromous form of char (malma) Salvelinus malma [Walbaum, 1792] from the Avacha River. The observed differences between aquaculture and wild juvenile char were associated with different food sources. The muscle tissue of juvenile char from natural habitat was characterized by significantly higher levels of fatty acids – biomarkers of diatoms, as well as biomarkers of marine copepods in the anadromous form. In the fatty acid composition of juvenile char from aquaculture, significantly higher levels of linoleic acid were revealed, as well as long-chain monounsaturated acids, the source of which could be aquaculture feed. The identified differences did not have a significant effect on the content of eicosapentaenoic and docosahexaenoic acids in the muscle tissue of juvenile aquaculture and wild char. The content of biochemically valuable omega 3 polyunsaturated fatty acids in juvenile char from natural ecosystems and aquaculture was similar.

The presence of DNA damage can increase the likelihood of DNA replication errors and promote mutations. In particular, pauses of DNA polymerase at the site of damage can lead to polymerase slippage and the formation of 1–2 nucleotide bulges. Repair of such structures using an undamaged DNA template leads to small deletions. One of the most abundant oxidative DNA lesions, 8-oxoguanine (oxoG), has been shown to induce small deletions but the mechanism of this phenomenon is currently unknown. We have studied the aberrant repair of oxoG, located in one- and two-nucleotide bulges, by the Escherichia coli and human base excision repair systems. Our results indicate that the repair in such substrates can serve as a mechanism for fixing small deletions in bacteria but not in humans.

The heterochromatin position effect is manifested in the inactivation of euchromatin genes transferred to heterochromatin. In chromosomal rearrangements, genes located near the new eu-heterochromatin boundary in the rearrangement (cis-inactivation) and, in rare cases, genes of a region of the normal chromosome homologous to the region of the eu-heterochromatin boundary of the chromosome with the rearrangement (trans-inactivation) are subject to inactivation. The In(2)A4 inversion is able to trans-inactivate the UAS-eGFP reporter gene located on the normal chromosome. We knockdown a number of chromatin proteins using temperature-controlled RNA interference and investigated the effect of knockdown on trans-inactivation of the reporter. We found suppression of trans-inactivation by knockdowns of Su(var)2-HP2, a protein that binds to the key heterochromatin protein HP1a, SAYP, a subunit of the chromatin remodelling complex, and Eggless histone methyltransferase (SETDB1), which introduces a H3K9me3 histone mark, recognized by the HP1a protein. The method of studying the effects of gene knockdown on heterochromatin position effects presented in this work is of independent methodological interest.

High-throughput ribosome profiling demonstrated the translation of thousands small open reading frames located in the 5′ untranslated regions of messenger RNAs (upstream ORFs). Upstream ORF can both perform a regulatory function by influencing the translation of the downstream main ORF, and encode a small functional protein or microprotein. In this work, we showed that the 5′ untranslated region of the PRPF19 mRNA encodes an upstream ORF that is translated in human cells. Inactivation of this upstream ORF reduces the viability of human cells.

This article presents the results of studying the impact of recombinant spidroin hydrogel on posterior epithelial cells and human corneal keratocytes in an in vitro experiment. The World Health Organization in its studies has established a high prevalence of corneal injuries among the population of developing countries. In recent years, various technologies have been proposed to restore the damaged surface of the cornea. The use of biodegradable silk-based materials, such as spidroins is one of the main parts of scientific research of corneal regeneration. Spidroinsare well known for their optimal balance of strength and elasticity, which, given their biological compatibility, non-immunogenicity and biodegradability, allows them to be used as a biomaterial for tissue engineering and regenerative medicine. In this reason a detailed assessment of the cytotoxicity of hydrogels based on recombinant rS2/12-RGDS spidroinon the epithelial cells and keratocytes was performed here, taking into attention possible changes of the phenotype and migratory activity of these cells. This study demonstrates the promise and therapeutic potential of hydrogels based on recombinant spidroin.

Delivery of ribonucleoprotein complexes of Cas9 nuclease and guide RNA into target cells with virus-like particles (VLP) is one of the novel methods of genome editing, suitable for gene therapy of human diseases in the future. Efficiency of genome editing with VLPs depends on the packaging of Cas9 into VLPs, that is mediated by viral Gag protein. To increase the packaging of Cas9 into NanoMEDIC system VLPs plasmid constructs for expression of Cas9 and Gag were modified by the addition of HIV RRE (Rev response element), that is expected to increase the nuclear export of RRE-containing transcripts to cytosol via accessory protein Rev, as described for Vpr-Cas9-based VLP system. Here we found that Cas9 and Gag protein levels in the cell lysates are increased upon cotransfection of either Rev-expressing plasmid or empty control plasmid. Moreover, this effect does not depend on the presence of RRE in the transcript. On the top of that, we showed that AP21967-induced dimerization of FRB and FKBP12, but not the modification of plasmids with RRE and/or cotransfection of Rev-expressing plasmid, plays the major role in packaging of Cas9 into NanoMEDIC system VLPs. These data suggest that it is impractical to use the RRE-Rev module to enhance the packing of Cas9 nuclease into VLPs.

The presented data on the study of the functional activity of the blood system of migratory species of the fauna of the Urals: Vespertilio murinus [Linnaeus, 1758], and Pipistrellus nathusii Keyserling et [Blasius, 1839]. Multivariate nonparametric analysis of variance of red blood parameters (p < 0.05) of migrating bats and the sedentary pond bat showed significant species differences. In bats, a certain genetically determined multidirectionality in the mobilization of emergency regulation mechanisms of the lymphoid blood system of sedentary and migratory species has been noted.

The effect of wheat seeds treatment with salicylic acid (SA) on the expression of the TaCu/ZnSOD, TaFeSOD and TaCAT2 genes and the activity of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) in leaves at the optimal content of zinc (2 µM) and copper (0.3 µM) in root environment or there deficiencies has been studied. It was shown for the first time that seeds treatment with SA leads to an increase of the number of genes transcripts compared to untreated plants, both under optimal conditions of mineral nutrition and under zinc or copper deficiency. The activity of enzymes, especially catalase, also increases. Judging by the MDA content, this allows one to avoid increasing the intensity of lipid peroxidation (LPO) and, accordingly, the development of oxidative stress. It is concluded that the discovered positive effect of seed treatment with SA on the activity of the main enzymes of antioxidant system may underlie the stimulating effect of this phytohormone on physiological processes in plants under microelements deficiency.

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease leading to inevitable disability and primarily affecting the young and middle-aged population. Recent studies have shown a direct correlation between the risk of MS development and Epstein-Barr virus (EBV) infection. Analysis of the titer of EBV-specific antibodies among patients with MS and healthy donors among Russian population confirmed that MS is characterized by an increased level of serum IgG binding EBNA-1 (EBV nuclear antigen 1). The number of patients with elevated levels of EBNA-1-specific antibodies does not differ statistically significantly between two groups with diametrically opposite courses of MS: benign MS or highly active MS. It can be assumed that the primary link between EBV and the development of MS is restricted to the initiation of the disease and does not impact its severity.

The study of swirling flows in channels corresponding to the static approximation of flow channels of the heart and major vessels with a longitudinal-radial profile zR² = const and a concave streamlined surface at the beginning of the longitudinal coordinate has been carried out. A comparative analysis of the flow structure in channel configurations zR^N = const, where N = –1; 1; 2; 3, in the absence and presence of a concave surface was carried out. The numerical modelling was compared with the results of hydrodynamic experiments on the flow characteristics and the shape of the flow lines. The numerical model was used to determine the velocity structure, viscous friction losses and shear stresses. Numerical modelling of steady-state flows for channels without a concave surface showed that in the channel zR² = const there is a stable vortex flow structure with the lowest viscous friction losses. The presence of a concave surface of sufficient size significantly reduces viscous friction losses and shear stresses in both steady state and pulsed modes.

During a study of morphological variation in bent-wing bats (Miniopterus), we found that specimens originating from the Cao Bang province of Vietnam, identified as M. fuliginosus, were closer in size to the larger species, M. magnater. Mitochondrial gene analysis clearly places these specimens in the former species. At the same time, morphometric analysis of 21 cranial measurements definitely puts these specimens closer to M. magnater and shows their differences from M. fuliginosus samples from different parts of the species range. We assume that in the low mountains of northern Vietnam and southern China, M. fuliginosus, due to as yet unknown circumstances, occupies the niche of a larger species. However insufficient data on nuclear markers also assume a hybrid origin of this population, which borrowed the mtDNA of another species..