Coronaviruses (CoVs) belong to the subfamily Orthocoronavirinae of the family Coronaviridae. CoVs are enveloped (+) RNA viruses with unusually long genomes. Severe acute respiratory syndrome CoV (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV), and the novel coronavirus (2019-nCoV, SARS-CoV-2) have been identif ied as causing global pandemics. Clinically tested vaccines are widely used to control rapidly spreading, acute, and often severe infections; however, effective drugs are still not available. The genomes of SARS-CoV-2 and SARS-CoV are approximately 80 % identical, while the genomes of SARS-CoV-2 and MERS-CoV are approximately 50 % identical. This indicates that there may be common mechanisms of coronavirus pathogenesis and, therefore, potential therapeutic targets for each virus may be the same. The enzymes and effector proteins that make up the replicationtranscription complex (RTC) of coronaviruses are encoded by a large replicase gene. These enzymes and effector proteins represent promising targets for potential therapeutic drugs. The enzyme targets include papain- and 3C-like cysteine proteinases that process two large viral polyproteins, RNA-dependent RNA polymerase, RNA helicase, viral genome-modifying enzymes, and enzymes with 3’–5’ exoribonuclease or uridylate-specif ic endonuclease activity. Currently, there are many studies investigating the complex molecular mechanisms involved in the assembly and function of the RTC. This review will encompass current, modern studies on the properties and complexes of individual non-structural subunits of the RTC, the structures of individual coronavirus RTC subunits, domain organization and functions of subunits, protein-protein interactions, properties and architectures of subunit complexes, the effect of mutations, and the identif ication of mutations affecting the viability of the virus in cell culture.

Mutant alleles of the Rht-B1 and Rht-D1 (Reduced height) genes are widely used in bread wheat breeding for the development of intensive-type cultivars. These genes and their f lanking regions have been sequenced and the point mutations leading to the nonsense codons (Rht-B1b, Rht-B1e, Rht-B1p and Rht-D1b alleles) and various insertions (Rht-B1c, Rht-B1h and Rht-B1i-1) associated with a change in plant height have been described. DNA-markers based on the allele-specif ic PCR have been developed to identify single-nucleotide changes. However, the use of such technique imposes stringent PCR conditions, and the resulting data are not always unambiguous. An alternative can be found in the CAPS technology: it detects differences in sequences by digesting PCR products. In the absence of restrictases capable of digesting DNA at the point mutation site, restriction sites can be introduced into the primer sequence (derived CAPS). The aim of this study was to propose a system of CAPS-, dCAPS- and STS-markers for identifying alleles of the reduced height genes frequently used in breeding programs. Three CAPS have been developed to identify the Rht-B1b, Rht-D1b, Rht-B1p alleles, as well as two dCAPS for Rht-B1b, Rht-B1e. STS-markers for the insertioncontaining alleles Rht-B1c, Rht-B1h and Rht-B1i-1 have been selected from publications. The proposed markers were tested during the genotyping of 11 bread wheat accessions from the VIR collection with the abovementioned mutant alleles and the wild-type Rht-B1a and Rht-D1a. The presence of nonsense mutations was also conf irmed by the results of allele-specif ic PCR. This marker system, along with the existing ones, can be used to identify dwarf ing alleles of the Rht-B1 and Rht-D1 genes in bread wheat for genetic screening of accessions from ex situ collections and/or for marker-assisted selection.

Wide hybridization in cereal crops is one of the most efficient tools for the enrichment of genetic variability and addressing a number of breeding problems related to resistance and tolerance to biotic and abiotic stresses. Therefore, a large number of amphidiploids between species possessing different morphological, genetic and physiological properties have been developed. One of the most valuable species with regard to the possibilities for introducing valuable traits and properties into wheat species is the wild Dasypyrum villosum. With the aim to study the androgenic response of the Triticum durum-D. villosum amphidiploids, two accessions and their parental forms – the durum wheat cultivars Gergana and Argonavt and a landrace of the D. villosum – were studied. The following parameters were determined: callus induction, plant regeneration, yield of albino and green regenerants. It was found that the callus induction of the two studied amphidiploids differed significantly from that of the parental forms (2.1–7.2 %), being significantly higher, 30.7 and 16.5 %, respectively. Regardless of the difference in callus induction, the amphidiploids did not significantly differ from the parental forms in their regeneration ability. The yield of albino plants exceeded the yield of green regenerants and followed the tendency observed in callus induction. Green plants were found only in the amphidiploid Gergana-D. villosum and in the parental form durum wheat Gergana. Plants were regenerated from the species D. villosum, although they were only albinos, showing its good responsiveness to anther culture. The established characteristics of the amphidiploids and their parental forms make their practical use highly valuable for the improvement of different types of cereal crops.

Correlations between the morphological features of f lower buds and the developmental stages of the male gametophyte are of great practical interest as a reliable marker that accelerates and simplif ies the selection of appropriate plant material for isolated microspore culture. Microspore culture enables one to quickly obtain many pure lines of different vegetable crops, but it has not yet been widely applied in the melon (Cucumis melo L.). To successfully apply this technique in a new culture, one has to optimize many of its elements: f irst, f ind the biological markers for selecting the f lower buds containing the microspores of certain development stages. The paper presents the results of research estimating the correlations between the length and diameter of the f lower buds, the length of the visual part of the corolla, the length of the anthers and the development stages of the male gametophyte in the F1 hybrid of the Kim Hong Ngoc melon. The strongest correlation (CC = 0.885) was found for the f lower bed diameter and a strong correlation (CC = 0.880), for the bud length. The corolla’s visual part was a less reliable morphological feature, and the anther’s length should not be used as a parameter to predict the developmental stages of the melon’s male gametophyte. It was also found that one anther could contain the microspores and pollen grains of different developmental stages. In the f lower buds less than 4 mm in length and 1.51 ± 0.02 mm in diameter prevailed tetrads, and in the buds 4.0–4.9 mm in length and 2.30 ± 0.02 mm in diameter, early microspores. The microspores of a middle stage of development prevailed in the f lower buds 5.0–5.9 mm in length and 2.32 ± 0.00 mm in diameter; mid and late vacuolated microspores, in the buds 6.0–8.9 mm in length and 2.96 ± 0.37 mm in diameter; and two-celled pollen, in the buds more than 9 mm in length and more than 3.97 ± 0.34 mm in diameter.

Ornithine aminotransferase (OAT) catalyzes transfer of the delta-amino group from L-ornithine to oxo-glutarate. In plants, this reaction biochemically connects urea cycle, proline cycle, and polyamine biosynthesis pathway. OAT activity is shown to be associated with biotic and abiotic stress responses and nitrogen metabolism, but its physiological role is still unclear. In our study, we decided to investigate transcriptional regulation of the OAT gene in Arabidopsis thaliana under normal conditions and in response to various growth regulators. In the present work, the reporter gene construct containing the Escherichia coli β-glucuronidase gene (gus) under control of the A. thaliana OAT gene promoter was introduced into the genome of A. thaliana ecotype Columbia plants using the floral dip method; GUS activity was assayed in different experimental conditions including hormone treatment, low and high nitrogen and salinity. The GUS activity was analyzed histochemically. Plants were incubated with staining solution containing X-Gluc. We show that under standard growth conditions, the promoter is active during germination and in developing floral organs. OAT promoter activity specifically activates in response to different forms of auxin (IAA, NAA, and 2,4D), cytokinin (6- BAP), ethylene precursor (ACC), high nitrogen and salinity. Analysis of the OAT expression by qRT-PCR confirmed the pattern observed using the GUS reporter system. The OAT gene showed a significantly elevated expression in fourday- old seedlings and in plant roots in response to auxins and cytokinins. The analysis of the OAT promoter structure reveals cis-acting regulatory DNA elements associated with auxin regulation and abiotic stresses. The results of the study indicate that the OAT gene is involved in developmental processes and is regulated by auxin and cytokinins.

The f ibroblast growth factor 21 (FGF21) synthesized in the liver, acting as a hormone, increases insulin sensitivity and energy expenditure. FGF21 administration has potent benef icial effects on obesity and diabetes in humans, cynomolgus monkey, and rodents. The therapeutic effects of FGF21 have been studied mainly in males. They are not always manifested in females, and they are accompanied by sex-specif ic activation of gene expression in tissues. We have suggested that one of the causes of sexual dimorphism in response to FGF21 is the effect of estradiol (E2). Currently, it is not known how estradiol modif ies the pharmacological effects of FGF21. The objective of this study was to study the inf luence of FGF21 on metabolic characteristics, food intake, and the expression of carbohydrate and fat metabolism genes in the liver, adipose tissue, and hypothalamus in female mice with alimentary obesity and low (ovariectomy) or high (ovariectomy + E2) blood estradiol level. In ovariectomized (OVX) females, the development of obesity was induced by the consumption of a high sweet-fat diet (standard chow, lard, and cookies) for 8 weeks. We investigated the effects of FGF21 on body weight, blood levels, food preferences and gene expression in tissues when FGF21 was administered separately or in combination with E2 for 13 days. In OVX obese females, FGF21, regardless of E2-treatment, did not affect body weight, and adipose tissue weight, or glucose tolerance but increased the consumption of standard chow, reduced blood glucose levels, and suppressed its own expression in the liver (Fgf21), as well as the expression of the G6pc and Acacα genes. This study is the f irst to show the modif ication of FGF21 effects by estradiol: inhibition of FGF21-inf luence on the expression of Irs2 and Pklr in the liver and potentiation of the FGF21-stimulated expression of Lepr and Klb in the hypothalamus. In addition, when administered together with estradiol, FGF21 exerted an inhibitory effect on the expression of Cpt1α in subcutaneous white adipose tissue (scWAT), whereas no stimulating FGF21 effects on the expression of Insr and Acacβ in scWAT or inhibitory FGF21 effect on the plasma insulin level were observed. The results suggest that the absence of FGF21 effects on body and adipose tissue weights in OVX obese females and its benef icial effect on food intake and blood glucose levels are not associated with the action of estradiol. However, estradiol affects the transcriptional effects of FGF21 in the liver, white adipose tissue, and hypothalamus, which may underlie sex differences in the FGF21 effect on the expression of metabolic genes and, possibly, in pharmacological FGF21 effects.

Drosophila melanogaster Hsp67Bc is a heat- and cold-inducible small heat shock protein that participates in the prevention of aggregation of misfolded proteins and in macroautophagy regulation. Overexpression of the Hsp67Bc gene has been shown to enhance macroautophagy in Drosophila S2 cells, and the deletion of this gene leads to the formation of a slightly increased number of autophagic vacuoles in the fruit f ly brain neurons. Recently, we found that Hsp67Bc-null D. melanogaster f lies have poor tolerance to cold stress (0 °C) of various durations. In the present work, we investigated how the Hsp67Bc gene deletion affects the f itness of fruit f lies under normal conditions and their tolerance to elevated temperatures at different developmental stages. Larvae and pupae were not adversely affected by the Hsp67Bc gene deletion, and adult Hsp67Bc-null f lies showed an extended lifespan in comparison with the control at normal (24–25 °C) and elevated temperature (29 °C), and after acute heat stress (37 °C, 2 h). At the same time, the fecundity of the mutant females was lower by 6–13 % in all tested environments, except for permanent maintenance at 29 °C, where the mean numbers of eggs laid by the mutant and control f lies were equal. We explain this phenomenon by a reduced number of ovarioles in Hsp67Bc-null females and enhanced macroautophagy in their germaria, which promotes the death of forming egg chambers. In addition, short heat stress (37 °C, 2 h), which increased the control line’s longevity (an effect common for a wide range of organisms), had a negative impact on the lifespan of Hsp67Bc-null f lies. Therefore, Hsp67Bc-null D. melanogaster have an extended lifespan under normal and elevated temperature conditions, and reduced fecundity and thermal stress tolerance.

Nonverbal intelligence represents one of the components of brain cognitive functions, which uses visual images and nonverbal approaches for solving required tasks. Interaction between the nervous and immune systems plays a specif ic role in individual differences in brain cognitive functions. Therefore, the genes encoding pro- and antiinf lammatory cytokines are prospective candidate genes in the study of nonverbal intelligence. Within the framework of the present study, we conducted the association analysis of six SNPs in the genes that encode proteins involved in inf lammatory response regulation in the central nervous system (CRP rs3093077, IL1А rs1800587, IL1B rs16944, TNF/ LTA rs1041981, rs1800629, and P2RX7 rs2230912), with nonverbal intelligence in mentally healthy young adults aged 18– 25 years without cognitive decline with inclusion of sex, ethnicity and the presence of the “risky” APOE ε4 allele as covariates. Considering an important role of environmental factors in the development of brain cognitive functions in general and nonverbal intelligence in particular, we conducted an analysis of gene-by-environment (G × E) interactions. As a result of a statistical analysis, rs1041981 and rs1800629 in the tumor necrosis factor gene (TNF) were shown to be associated with a phenotypic variance in nonverbal intelligence at the haplotype level (for АА-haplotype: βST = 1.19; p = 0.033; pperm = 0.047) in carriers of the “risky” APOE ε4 allele. Gene-by-environment interaction models, which determined interindividual differences in nonverbal intelligence, have been constructed: sibship size (number of children in a family) and smoking demonstrated a modulating effect on association of the TNF/LTA (rs1041981) (β = 2.08; βST = 0.16; p = 0.001) and P2RX7 (rs2230912) (β = –1.70; βST = –0.10; p = 0.022) gene polymorphisms with nonverbal intelligence. The data obtained indicate that the effect of TNF/LTA on the development of cognitive functions is evident only in the presence of the “unfavorable” APOE ε4 variant and/or certain environmental conditions.

Investigation of the frequencies of functionally signif icant gene variants in the context of medical biology and gene geography is a relevant issue for studying the genetic structure of human populations. The transition from a traditional to an urbanized lifestyle leads to a higher incidence of civilizational diseases associated with metabolic disorders, including type 2 diabetes mellitus. The goal of the present paper is to analyze the frequencies of functionally signif icant gene alleles in the metabolic prof iles of indigenous Siberian peoples to identify the gene pool resilience, evaluate the susceptibility of various ethnic groups to metabolic disorders under changing environmental conditions, and predict the epidemiological situation that may occur in the near future. The study was performed in the monoethnic samples of eastern and western Buryats, Teleuts, Dolgans, and two territorial groups of Yakuts. A real-time PCR was used to determine the frequencies of single nucleotide polymorphisms (SNPs) G103894T, rs12255372, and C53341T, rs7903146 in the TCF7L2 gene. The results obtained were compared to the frequencies identif ied for Russians from Eastern Siberia and the values available in the literature. The frequencies of the polymorphic variants studied in the samples from the indigenous Siberian peoples place them in between Caucasian and East Asian populations, following the geographic gradient of polymorphism distribution. A signif icantly lower occurrence of type 2 diabetes risk alleles TCF7L2 (103894T) and TCF7L2 (53341T) in the samples of indigenous Siberian peoples compared to Russians was observed, which agrees with their lower susceptibility to metabolic disorders compared to the newcomer Caucasian population. Taking into account urbanization, a reduced growth in type 2 diabetes incidence may be predicted in indigenous Siberian peoples, i. e. Buryats, Yakuts, Dolgans, and Teleuts, compared to the newcomer Caucasian population. A further study of population structure with respect to different metabolic prof ile genes is required to better understand the molecular genetic foundations of the adaptive potential of indigenous Siberian peoples.

An infrared thermometer was first used to assess drought and heat tolerance in plant breeding more than 40 years ago. Soon afterward, this method became widely used throughout the world. However, Russia has not yet applied the described method for evaluating stress tolerance. This paper presents an overview of using infrared thermometry in plant breeding. Taking wheat as an example, it shows major advantages and disadvantages of canopy temperature depression (CTD) values measured by the infrared thermometer. The paper also demonstrates that genotypes with higher CTD values, and therefore with a lower canopy temperature, use more available soil moisture under drought stress to cool the canopy by transpiration. It refers to CTD as an integrative trait that reflects an overall plant water status. Its coefficient of variation lies in the interval of 10 to 43 %. A large number of publications illustrate a close relation between CTD values and yield and indicate a high heritability of the former. Meanwhile, the same works show that yield has a higher heritability. Moreover, some researchers doubt that CTD should be used in applied wheat breeding as there are many factors that influence it. CTD has a high correlation with other traits that reflect plant water status or their adaptation to drought or heat stress. Quantitative trait loci (QTLs) associated with CTD are localized in all chromosomes, except for 3D. These QTLs often explain a small part of phenotypic variance (10–20 %, more likely less than 10 %), which complicates the pyramiding of canopy temperature genes through marker-assisted selection. The paper concludes that the evaluation of CTD appears to be a reliable, relatively simple, labor-saving, objective, and non-invasive method that sets it apart from other methods as well as shows the best results under terminal drought and heat stress conditions.

Plant diseases cause signif icant economic losses in agriculture around the world. Early detection, quantif ication and identif ication of plant diseases are crucial for targeted application of plant protection measures in crop production. Recently, intensive research has been conducted to develop innovative methods for diagnosing plant diseases based on hyperspectral technologies. The analysis of the ref lection spectrum of plant tissue makes it possible to classify healthy and diseased plants, assess the severity of the disease, differentiate the types of pathogens, and identify the symptoms of biotic stresses at early stages, including during the incubation period, when the symptoms are not visible to the human eye. This review describes the basic principles of hyperspectral measurements and different types of available hyperspectral sensors. Possible applications of hyperspectral sensors and platforms on different scales for diseases diagnosis are discussed and evaluated. Hyperspectral analysis is a new subject that combines optical spectroscopy and image analysis methods, which make it possible to simultaneously evaluate both physiological and morphological parameters. The review describes the main steps of the hyperspectral data analysis process: image acquisition and preprocessing; data extraction and processing; modeling and analysis of data. The algorithms and methods applied at each step are mainly summarized. Further, the main areas of application of hyperspectral sensors in the diagnosis of plant diseases are considered, such as detection, differentiation and identif ication of diseases, estimation of disease severity, phenotyping of disease resistance of genotypes. A comprehensive review of scientif ic publications on the diagnosis of plant diseases highlights the benef its of hyperspectral technologies in investigating interactions between plants and pathogens at various measurement scales. Despite the encouraging progress made over the past few decades in monitoring plant diseases based on hyperspectral technologies, some technical problems that make these methods diff icult to apply in practice remain unresolved. The review is concluded with an overview of problems and prospects of using new technologies in agricultural production.

HIV infection still remains a major challenge for healthcare systems of the world. There are several aspects on counteracting the HIV/AIDS epidemic. The f irst aspect covers preventive measures including educational campaigns on HIV/AIDS and promotion of a healthy lifestyle, protected sex, and pre-exposure prophylaxis of vulnerable groups. The second aspect is timely HIV testing and the use of antiretroviral therapy when test results come back positive. The third aspect is the scientif ic research associated with discovering new pharmaceutical agents and developing HIV-1 vaccines. Selecting an adequate tool for quick and accurate in vitro eff icacy assessment is the key aspect for eff icacy assessment of vaccines and chemotherapy drugs. The classical method of virology, which makes it possible to evaluate the neutralizing activity of the sera of animals immunized with experimental vaccines and the eff icacy of chemotherapy agents is the method of neutralization using viral isolates and infectious molecular clones, i. e. infectious viral particles obtained via cell transfection with a plasmid vector including the full-length HIV-1 genome coding structural, regulatory, and accessory proteins of the virus required for the cultivation of replication-competent viral particles in cell culture. However, neutralization assessment using viral isolates and infectious molecular clones is demanding in terms of time, effort, and biosafety measures. An alternative eliminating these disadvantages and allowing for rapid screening is the use of pseudoviruses, which are recombinant viral particles, for the analysis of neutralizing activity. Pseudotyped viruses have defective genomes restricting their replication to a single cycle, which renders them harmless compared to infectious viruses. The present review focuses on describing viral model systems for in vitro eff icacy assessment of vaccines and drugs against HIV-1, which include primary HIV-1 isolates, laboratoryadapted strains, infectious molecular clones, and env-pseudoviruses. A brief comparison of the listed models is presented. The HIV-1 env-pseudoviruses approach is described in more detail.