The highly conserved MTG gene family includes three homologs in vertebrates (MTG8, MTGR1, MTG16) encoding transcriptional corepressors, which are important in haemopoiesis, neurogenesis and epithelial stem cell differentiation. These genes are of particular interest because they are involved in translocations, associated with different types of cancer. Looking at how this gene family evolved might provide insights into history of its structural and functional diversification. We have performed a phylogenetic analysis of MTG nucleotide and protein sequences to examine the evolutionary events. The domain organization of MTG gene products was clarified, the mechanism of appearance of the first MTG gene was revealed and the ancestor taxon was determined. Also the mechanism of MTG gene family emergence was established. In addition, analysis of the rates of evolution acting on individual domains was made, and conservative positions within each gene of MTG family were determined.

The article describes results of a comparative study of variability of 14 quantitative characteristics of biochemical composition of fruits in sort rows of 4 species of introduced varieties of Ericaceae (Oxycoccus macrocarpus, Vaccinium corymbosum) and Actinidiaceae (Actinidia arguta, Actinidia kolomikta) families, which has shown its lowest dependence on genotype in O. macrocarpus and the greatest dependence in A. arguta while the species studied have similarities in the level of genetic determinancy of a number of characteristics of fruits biochemical composition. It has been shown that the lowest stability in sort rows of both species of Ericaceae fam. is typical of parameters of accumulating anthocyanins proper and leucoanthocyanins while the greatest stability – that of ascorbic acid, which is characterized by high variability in both species of Actinidiaceae family. Most species of introduced plants studied have the lowest variability in sort rows in content of soluble sugars and total amount of bioflavonoids in fruits, while the greatest one – in sugar-acid index and tannins content. It has been found out that V. corymbosum and A. arguta have little dependence of flavonols content in fruits on genotype while V. corymbosum and A. kolomikta – that of pectin substances with a strong dependence of parameters of accumulating the latter in O. macrocarpus and A. arguta.

The article presents the results of determining the activity of lipid peroxidation (LPO) in biological membranes of the reed fescue Festuca arundinacea Schreb. plants in an experiment on the processing of leaf blades with different amounts of volatile organic compounds (pentane, hexane, benzene, o-xylol, benz(a)pyrene, butylacetate and their mixtures). Taking into account the dynamics of the content of malonic dialdehyde – of a stable product of LPO, it was established during the experiment that the effect of benzene, o-xylol, butyl acetate and all mixtures caused a more significant increase LPO in 1 day after treatment compared to 3 days of the experiment. At the same time, o-xylene and a mixture of pentane, hexane, and benz(a)pyrene exerted the most intense effect on the processes of LPO in comparison with other compounds. After 3 days, the amount of malonic dialdehyde changed more intensively compared to 1 day after treatment with pentane, hexane and benz(a)pyrene, and pentane and hexane caused more pronounced differences compared to benz(a)pyrene.

Molecular diagnostic tests based on PCR preceded by reverse transcription (RT-PCR) are now used commonly for the detection of viral pathogens with RNA genomes. The application of internal controls to validate the entire process of these assays is necessary to prevent false-negative results caused by inhibition or inefficient extraction. In the present study a strategy to produce a new type of internal control for RT-PCR based on recombinant retroviral particles is described. Cell clones stably producing retroviral particles were established by transfecting GP+env-AM12 packaging cells with constructed MoMuLV-derived retroviral vector pLneo/gfp and subsequent cultivation on selective medium with G418. The egfp gene was used as a target for primers and hybridization probe design for real-time RT-PCR assay and as a marker for flow cytometry analysis of eGFP expression by transfected cells. The developed internal control is stable and ribonuclease resistant, economical to produce, noninfectious and safe for routine use. It closely mimics the natural virus and could be successfully used to monitor all the stages of RT-PCR, including nucleic acid extraction, RNA reverse transcription and amplification.

The steam distillation method was used to obtain samples of essential oil of Pseudotsuga menziesii introduced in Republic of Belarus. More than 20 components have been identified and determined in the essential oil of Pseudotsuga menziesii by gas liquid chromatography. The dominant components are bornylacetate (~25–30 %), camphene (~14–15 %), α-pinene (~7–8 %), β-pinene (~8–10 %). Distribution of the enantiomers of the main components of Pseudotsuga menziesii essential oil are shown. It was determined the optical purity of oil to (–)-bornylacetate. The antimicrobial activity of Pseudotsuga menziesii essential oil was detected in relation to test cultures of gram-positive and gram-negative bacteria. Gram-positive bacterial cultures were more sensitive to the inhibitory effect of essential oil. The effect of the optical activity of essential oil dominant components on antimicrobial properties is shown.

It was revealed that the main component of the studied samples composition of the essential oil of Nigella is monoterpene p-cymene, the content of which is ~ 60 %. According to the results of the study of the fatty acid composition of the seed lipids of the studied samples, the prevalence of omega-6 (linoleic) and omega-9 (oleic) unsaturated fatty acids was found (75.11–76.91 % of the total fatty acid content). Samples of NP-13/2 (sum of omega-acids 77.56 %, linoleic acid content – 60.16 %) and NP-4 (sum of omega-acids 77.55 %, oleic acid content – 18.12 %) are promising. In the process of studying the amino acid composition in seed extracts, four essential (leucine, methionine, valine, threonine) and four essential (arginine, proline, serine, glycine) amino acids were identified. A promising sample was NP-13/4 (the sum of amino acids is 62.23 %, the arginine content is 17.56 mg/kg, the leucine is 4.95 mg/kg, and threonine is 4.12 mg/kg). The obtained data testify to the value of using not only ecologically and geographically distant forms, but also samples of hybrid origin of nigella sown, selected and adapted to the conditions of Belarus, as source material in breeding work when creating varieties of medicinal purpose.

Relationship between the diel leaf growth of capsicum and proliferative activity of cells has been investigated using a computer-aided image analysis. It has been established the leaf growth pattern observed in this species allows to refer it to the second type of growth of dicotyledons, which is characterized by the maximum growth rate in the evening or at the beginning of the night. A DNA cytometry study of leaf cells shows that their proliferative activity is also higher at night than during the day. This suggests that the diel rhythm of capsicum leaf growth is due to the synchronization of cell cycle with a lighting.

The peculiarities of the influence of LED-lighting of different spectral composition with varying ratios of physiologically significant spectral ranges on biometric parameters and the pigment composition of the leaf plate of microclonally propagated aspen (Populus tremula L.) and birch (Betula pendula Roth.) plants were identified during the adaptation ex vitro, which indicate the species specificity of plants response to the illumination spectrum.

The primary purification of the proteolytic enzyme preparation from the Pleurotus ostreatus culture fluid was carried out. Methods of salting out, dialysis, ion-exchange chromatography on DEAEand KM-sepharose were used. It was shown that during the chromatography on KM-sepharose, the enzyme preparation from the culture liquid was divided into three fractions, one of which possessed milk-clotting activity (МСА). Chromatography on DEAE-sepharose allowed us to reach the significant purity of the enzyme with МСА.

The results of White Stork Ciconia ciconia study on monitoring plot (area of 100 km2, Volozhin district, Minsk Region) in 2004–2018 are analyzed: numbers, spatial distribution, breeding success and location of nests on different supports. Decrease of numbers, significant reduction of breeding success and grow the rate of using electric pylons for nesting are allowed to make an unfavourable prognosis for population.

The paper presents the results of studies of the number and spatial distribution of 17 species of waterbirds on the territory of the “Dokudovskoye” peat development in the Lida district of the Grodno region. in 2012–2018. Based on the analysis of the dynamics of population indicators and changes in the structure of the habitat, three main factors affecting the bird community of the flooded peatland were identified: hydrological, biotopic, and disturbance factors.

It was identified the species composition of beetles (Coleoptera) on the fields of spring rape was revealed in different months of the summer periods of 2016 and 2017. A conclusion is made about the dependence of the species diversity of coleopterans on the collection time of the samples. In 2016 and 2017 years on the experimental fields, representatives of 9 families of Coleoptera were found: sap beetles (Nitidulidae), ladybird beetles (Coccinellidae), antlike flower beetles (Anthicidae), minute scavenger beetles (Latridiidae), silken fungus beetles (Cryptophagidae), soldier beetles (Cantharidae), burying beetles (Silphidae), clown beetles (Histeridae) and click beetles (Elateridae). A total of them were 27 species of beetles.

The sociological analysis of the briocomponent of deciduous forests within Belarus is presented in the article. There are 270 species of bryophytes (Bryobionta), 63 of which are liverworts (Marchantiophyta) and 207 mosses (Bryophyta). 94 species are at present to some extent rare or have long been not found, including 13 rare species, and 13 – species in need of preventive protection.

Stellate tabpole-goby Benthophilus stellatus (Sauvage, 1874) is one of 5 representatives of the goby family (Gobiidae) in Belarus, discovered in 2011 in the Dnieper River. Until now, this species within Belarus is practically haven’t been studied and is of interest for the study as a new species in the freshwater watercourses. Standard ichthyological methods of trapping and methods of processing the material have been used in the study. A total of 39 morphometric characteristics are investigated, however, the comparison with the specimens from the natural habitat was carried out by individual indicators using a two-sample t-test for independent samples (tst). The analysis of stellate tabpole-goby plastic characteristics from the Belarusian section of the Dnieper River is presented for a first time and the meristic characteristics data of the species on this section of the river is supplemented. There were significant differences on 3 meristic and 11 plastic features from the individuals of the stellate tabpole-goby from the Kakhovka reservoir (Ukraine, the lower reaches of the Dnieper River).

The analysis of literature data on one of the actual problem of modern cell biophysics and biotechnology dealing with mesenchimal stem cells and cordial progenitor cells taking part in reparation of myocardium after its injury and first of all after myocardial infarction was done. Biological properties and potential ability of these cells in reparation processes of myocardium are considered. The recent data on experiments using experimental animals and patients are given. The approaches to increase the efficacy of сell technologies in treatment of injured cardiomyocytes are discussed.