Biological education in Belarusian State University for 100 years

The article is dedicated to the centenary of Belarusian State University and the centenary of biological university education in Belarus. The history of the faculty of biology is described, a retrospective of the development of its units since 1921 is presented. The most significant personalities and events are highlighted. The inseparable connection between the life of the faculty and the university as a whole is demonstrated.

Physiological and biochemical mechanisms of plants resistance to oxidative stress under peptide elicitor AtPep1

The effect of the peptide elicitor AtPep1 on the resistance of soybean and pea plants to oxidative stress was studied. The concentration of the peptide 10– 9 mol/L has the maximum elicitor effect on these plants. It was shown that treatment of the aerial part of seedlings with this peptide leads to an increase in the activity of peroxidase and superoxide dismutase and a decrease in the level of lipid peroxidation products in plants under oxidative stress. Revealed effects cause an increase in the plants resistance to stress.

The ability of the natural chemoprophylactic agent curcumin to function as an effective UV photosensitiser

It is known that some plant polyphenols and alkaloids can act as effective photosensitisers of UV radiation. This phenomenon can enhance both therapeutic and side effects. Since there is no information regarding curcuminoids on their ability to function as UV photosensitisers, this work investigated the effect of UV radiation on the cytotoxic effect of curcumin, as well as its nanostructured forms, against keratinocytes of the HaCaT line and cancer cells MDA-MB-231. The results obtained indicate that curcumin is an effective photosensitiser capable of initiating photochemical reactions under the influence of UV radiation of the A and B range, which lead to the formation of chemically active intermediates, disruption of membrane integrity and cell death. When curcumin is incorporated into nanostructures based on polyallylamine hydrochloride /polystyrene sulfate and chitosan /dextran sulfate, its ability to function as a UV photosensitiser is retained.

Seasonal dynamics of zooplankton in lakes of different trophic status

In the article, we present the data about the dominant complexes of zooplankton species in the pelagic zone of lakes Naroch, Myastro, Batorino (2014 –2019), Malye and Bolshie Shvakshty (2014 –2015), Svir (2018). The seasonal dynamics of zooplankton is analysed. The contribution of taxonomic groups and individual species in the abundance and biomass of zooplankton in lakes with different trophic status is studied. We noted two peaks in the seasonal dynamics of zooplankton. Rotifers prevailed in the spring, while Crustacea dominated in the summer-autumn period. The relative biomass of cladocerans increased and the proportion of copepods decreased with the increasing of trophic status of the lakes.

Restriction-modification systems and DNA methylation profile of Pectobacterium carotovorum 2A

The methylation profile of Pectobacterium carotovorum 2A genome was studied using the Oxford Nanopore sequencing technology. The specificity of the methylase subunits of the three restriction-modification systems of this strain was determined. Analysis of homologous systems showed the uniqueness of the type I restriction-modification system and the type IV restriction system specific to methylated DNA of this strain. The work confirms the applicability of Oxford Nanopore technology to the analysis of bacterial DNA modifications and is also the first example of such an analysis for Pectobacterium spp.

Population genetic structure of pedunculate oak (Quercus robur L.) in Belarus according to the analysis of chloroplast DNA

Pedunculate oak (Quercus robur L.) is one of the main forest forming species in the Republic of Belarus. Its population genetic structure was formed under the influence of various migration processes. Six chloroplast DNA loci (µdt1, µdt3, µdt4, µcd4, µcd5 and µkk4) were used for the genogeographic study. The material for the analysis was collected in 100 oak forest stands (2325 samples); 18 allelic variants were identified, which are grouped into 17 different combinations (haplotypes). Five of them are widespread (the proportion of occurrence varies from 7 to 48 %, totalling 85 %). The remaining 12 are rare (the proportion of occurrence varies from 1 to 3 %, totalling 15 %). Phylogenetic trees constructed using the nearest neighbour and maximum likelihood methods show the presence of two groups (branches) of haplotypes. One of it comprises 8 variants including 2 dominant haplotypes and the other comprises 9 variants including 3 dominant haplotypes. PCR-RFLP analysis of chloroplast DNA showed that the pedunculate oak in Belarus originates from the Balkan refugium. Haplotype No. 1 (µdt189, µdt3123, µdt4142, µcd494, µcd574, µkk4109) is found almost everywhere in Belarus with the exception of the southwest and northeast, while haplotype No. 8 (µdt189, µdt3121, µdt4142, µcd494, µcd574, µkk4109) is mainly localised in the southwest and northeast. Haplotypes No. 3 (µdt189, µdt3120, µdt4141, µcd494, µcd575, µkk4109) and No. 7 (µdt189, µdt3122, µdt4142, µcd494, µcd574, µkk4109) predominantly found in the west of the country. Haplotype No. 2 (µdt190, µdt3120, µdt4141, µcd495, µcd574, µkk4109) is typical for the southeast.

The influence of the stereotypic forms of activity in mice behaviour in standard behavioural tests

Laboratory animals often develop abnormal repetitive (stereotypic) behaviour that can influence both physiology and behavioural test results. Such abnormal behaviours usually develop in suboptimal environment and increase over time. To explore the development of stereotypic forms of activity night home-cage behaviour of laboratory mice was analysed and collated with the behaviour in open field (OFT), hole-board (HBT) and tail suspension (TST) tests twice within 16 weeks. Mice expressed few stereotypies and their duration lessened over time from median 8.2 to 1.0 %. In contrast, grooming behaviour increased significantly from 29.5 to 49.6 %. Home-cage grooming correlated with the latency of locomotion start in OFT and with the immobility time in TST. Intensity and stability of stereotypic activity and grooming inf­luenced the duration of grooming in OFT: the mice with unstable stereotypies groomed more than others, and mice with the lowes home-cage grooming level also groomed in OFT the most. Intensity and stability of night grooming influenced the behaviour in TST: the mice with unstable level of grooming were the most mobile in this test. Abnormal home-cage activity may indicate impaired welfare, and that, in turn, may affect test activity, so researchers need to keep it in mind when planning animal behaviour experiments.

Characteristics of cryoprotectors used for long-term storage of donor dendritic cells

Monocyte-derived donor dendritic cells are promising for use in the treatment of cancer. However, there are some problems that currently limit their clinical use. One of which is the cryopreservation of cells followed by restoration on demand. А cryoprotector must be added to the nutrient medium in order to reduce or completely eliminate the damaging factors acting on cells during freezing. Cryoprotectors refer to a wide range of sugars, diols and amino acids that stabilise biomolecules in various ways, depending on their molecular weight and mechanism of action on cells. The work describes groups of cryoprotectors (endo- and exocellular, mixed and combined cryoprotectors), as well as presents techniques of cryopreservation of dendritic cells.

Phytopathogenic micromycetes on alien plants from the publication «Black book of the flora of Belarus: alien harmful plants»

The 228 species of phytopathogenic micromycetes parasitising alien plants included in the publication «Black book of the flora of Belarus: alien harmful plants» (Minsk, 2020) were identified in the course of the conducted research. It was found that out of 322 plant species listed in this edition phytopathogenic micromycetes were found on 182 species (56.5 %). It is noted that among the phytopathogenic micromycetes only 92 species and intraspecific taxon (40.4 %) belong to the alien species of the Republic of Belarus. Obviously, these phytopathogens are highly specialised and currently parasitise only on these invasive plant species. The remaining 136 species and intraspecific taxon (59.6 %) affect both native and alien plant species.

ATP synthase in rat brain neurons

Mitochondrial ATP synthase is the main enzyme of ATP synthesis. A large number of diseases, including neurodegenerative ones, are associated with disorders of its assembly and functioning. The aim of the work is to reveal the patterns and features of the regional distribution of ATP synthase in the neurons of the rat brain structures, with a quantitative assessment of its content at the cellular level. The study was carried out on material from 5 outbred white male rats. Paraffin sections were stained by the Nissl method to identify structures of the brain and cervical segments of the spinal cord, and for ATP synthase by immunohistochemical method; 102 structures of the rat brain were studied cytophotometrically. Immunoreactivity of ATP synthase was found in all structures of the rat brain with high heterogeneity, while most structures are characterised with a moderate content of ATP synthase. A high content of ATP synthase was found in large neurons and in neurons of structures of phylogenetically older brain divisions. The content of ATP synthase also depends on the layer of the cortex and the position of neurons in the reflex arc. In the spinal cord the content of ATP synthase depends not only on the size of neurons, but also on the gray matter layer.