It was shown for the first time that preliminary deuteration of Esherichia coli bacteria with deuterium oxide (D 2 O) at concentrations from 5 to 10% in a medium leads to an enhancement of the SOS response in the biosensors E. coli MG1655 (pColD::lux) and E. coli MG1655 (pRecA::lux) induced by UV at a dose of 12 J/m 2 . The biosensors used in this work contain hybrid plasmids carrying the luxCDABE operon of the Photorhabdus luminescens photobacterium, placed under the control of the cda ( colD ) and recA gene promoters. The induction of genotoxic factors in biosensors indicates the activation of the corresponding E. coli SOS system of gene expression. A simultaneous study of the intensity of luminescence and the cell viability of the E. coli MG1655 biosensor (pCol-lux) bacteria showed that UV irradiation at a dose of 12 J/m 2 increases the intensity of luminescence from 2111.1 in a medium without D 2 O to 5030.3 RLU for 10 7 viable cells in a medium with D 2 O. The intensity of luminescence of the biosensor was 2.5 times higher in the medium with deuterium than without it.

BACKGROUND: A common non-selective systemic herbicide Roundup (Glyphosate, active ingredient N-phosphonomethylglycine, N-PMG) is used to control perennial weeds. It is necessary to assess the hazard of the products of photochemical decomposition of N-FMG formed under the influence of solar UV and ozone. AIM: Using lux-biosensors based on Escherichia coli, studying the ability of N-FMG photochemical degradation products to induce oxidative stress in bacterial cells. MATERIALS AND METHODS: The work used the active substance of the herbicide Roundup N-phosphonomethylglycine (N-PMG), biosensors E. coli (pSoxS-lux), E. coli (pKatG-lux). UV radiation, Mass spectrometry. RESULTS: Using biosensors, it was shown that the products of photochemical decomposition of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) cause an increase in the concentration of superoxide anion radical and H2O2 in E. coli cells, which induces oxidative stress in the bacterial cell. CONCLUSIONS: The photochemical decomposition product of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) induces the formation of superoxide anion radical and H2O2 in bacterial cells.

In connection with the requirements of international and national organizations to comply with ethical principles for experiments using animals, alternative test systems are being sought and tested to replace animals in ecological, toxicological, and genotoxicological studies. One such alternative may be the nematode Caenorhabditis elegans, which has a biotransformation system of chemical compounds similar to the mammalian system. The genotoxicity of the pesticide paraquat and the antibacterial agent furacilin was studied on C. elegans by horizontal gel electrophoresis of total DNA in order to assess its integrity. It has been shown that paraquat in concentrations of 0.01 to 0.05 mol/L and furacilin in concentrations of 0.0001 and 0.00025 mol/L caused DNA breaks in nematode cells. The antioxidant N-acetylcysteine at a concentration of 0.01 mol/L reduced the genotoxicity of both compounds.

The aim of this study was to assess the applicability of the bacterial lux biosensors for genotoxicological studies. Biosensors are the strains of E. coli MG1655 carrying a recombinant plasmid with the lux operon of the luminescent bacterium P. luminescens fused with the promoters of inducible genes: recA, colD, alkA, soxS, and katG. The genotoxicity of forty-seven chemical compounds was tested on a set of three biosensors pSoxS-lux, pKatG-lux and pColD-lux, which allowed us to estimate the oxidative and DNA-damaging activity of the analyzed drugs. The comparison of the results with the data on the mutagenic activity of these drugs from the Ames test showed a complete coincidence of the results for the 42 substances. First, using lux biosensors, we have described the enhancing effect of the heavy non-radioactive isotope of hydrogen deuterium (D2O) on the genotoxicity of chemical compounds as possible mechanisms of this effect. The study of the modifying effect of 29 antioxidants and radioprotectors on the genotoxic effects of chemical agents showed the applicability of a pair of biosensors pSoxS-lux and pKatG-lux for the primary assessment of the potential antioxidant and radioprotective activity of chemical compounds. Thus, the results obtained showed that lux biosensors can be successfully used to identify potential genotoxicants, radioprotectors, antioxidants, and comutagens among chemical compounds, as well as to study the probable mechanism of genotoxic action of test substance.

The active ingredient of pesticide roundup (glyphosate), N-(phosphonomethyl)glycine (NPMG), was exposed to UV radiation at lambda = 250-600 nm. Ozone with the 2.5% oxygen content was bubbled through the NPMG reaction solution at a rate of 3.35 mmol h-1 (or 160.8 mg of ozone per hour). The decomposition NPMG is a complicated multistep process. It is practically impossible to identify NPMG in the solution after 14.3 h. The toxicological effect of both NPMG aqueous solutions and its phototransformation products were analyzed using the following assays: preparation of luminescent bacteria of the Ecolum series and infusoria Tetrahymena pyriformis. The cells of the latter were counted on a BioLat automated device with computer processing of the results. The toxicity of NPMG is retained until its 1000-fold dilution with pure water, while the 100-fold dilution of the irradiated sample was enough to eliminate its toxicity. It means that UV irradiation of NPMG together with its ozone treatment results in a 10-fold decrease in toxicity both in the case of Ecolum test system and that of T. pyriformis. The comparative study of the genetic effects for two genetic bacterial test systems shows that the phototransformation products contain substances with weak mutagenic and genotoxic activity. The obtained data indicate a high potential of the NPMG toxicity elimination method involving the UV irradiation of NPMG combined with the ozone treatment.

For the first time, lux biosensors of E. coli and the nematode Caenorhabditis elegans were used to study the genotoxicity of beta-propiolactone (BPL) used in the production of inactivated viral vaccines as an inactivator. It has been shown that the DNA-damaging activity of BPL is due not only to its ability to bind to bacterial DNA, but also to the ability to generate in the cell reactive oxygen species such as superoxide anions and peroxide, which have genotoxic activity. It was found that BPL in a dose-dependent manner, starting from a concentration of 0.001 mol/L, reduces the survival of bacteria. However, the intensity of expression of the antioxidant defense gene of superoxide dismutase soxS and the DNA repair gene colD increased. BPL-induced DNA breaks in nematode cells were detected by electrophoresis. The antioxidant acetylcysteine reduced the genotoxic effects of BPL on both bacteria and the nematode.

Paraquat at a concentration of 0.01 mol/L induces intense luminescence of E. coli pSoxS-lux and E. coli pKatG-lux biosensors, which indicates the formation of the superoxide radical anion (О 2– ) and hydrogen peroxide (Н 2 О 2 ), respectively, in bacterial cells. At a paraquat concentration of 0.1 mol/L, the luminescence intensity of biosensors decreases, as does bacteria viability from 4 × 10 7 colony-forming units (CFU) in the control to 1 × 10 5 CFU in the experiment. When recalculating the luminescence intensity index per 1000 CFU, the expression of the superoxide dismutase gene increases sharply from 0.13 in the control to 4.36 and 119 conventional units at paraquat concentrations of 0.01 and 0.1 mol/L, respectively. The antioxidants (glutathione and N-acetylcysteine) reduce the concentration of free radicals generated by paraquat in cells and increase the bacterial viability. The method of gel electrophoresis reveals the DNA-damaging ability of paraquat at a concentration of 0.1 mol/L, reduced by antioxidants.

Results of expression studies can be useful to clarify the genotype-phenotype relationship. However, according to data from recent literature, there is a large group of genes that are revealed as differentially expressed (DE) in many studies, regardless of the biological context. Additional analyses could shed more light on the relationships between genes, their differential expression, and diseases. We generated a set of 9972 disease genes from five gene-phenotype databases (OMIM, ORPHANET, DDG2P, DisGeNet and MalaCards) and a report of the International Union of Immunological Societies. To study transcriptomics of disease and non-disease genes in healthy tissues, we obtained data from the Human Protein Atlas (HPA) website. We analyzed the dependency between expression in healthy tissues and gene occurrence in Gene Expression Omnibus series using tools within the Enrichr libraries. The results of expression studies were annotated with Gene Ontology (GO) and Human Phenotype Ontology (HPO) terms. Using transcriptomics analysis of healthy tissues, we validated the previous findings of higher expression levels of disease genes in pathologically linked tissues compared to other tissues. Preferentially DE genes were generally highly expressed in one or multiple tissues and were enriched for disease genes. According to the results of GO enrichment analyses, both down- and up-regulated DE genes most often took part in immune response, translation and tissue-specific processes. A connection between DE-related pathology and the diversity of HPO terms was found. Investigating a link between expression and phenotype contributes to understanding the mode of development and progression of human diseases.

The global pollution of environment urges the screening of effective natural protectors for the correc-tion of toxic and genotoxic action of xenobiotics. Medicinal herbs contain a complex of biologically ac-tive compounds that are the potential sources of such a protective agent. In current study the mutagenic and antimutagenic activity of alcoholic extracts of peppermint (Mentha piperita L.) and thyme (Thymus vulgaris L.), family Lamiaceae, was studied using the chromosome aberration assay (metaphase cytoge-netics) in barley. The ability of extracts to significantly reduces methyl methanesulfonate-induced mu-tagenesis under preliminary or subsequent tinctures exposure was established (p<0.05). The modifying effect of peppermint and thyme tinctures was also studied under the exposure to rocket fuel unsymmetri-cal dimethylhydrazine (UDMH, 1,1-dimethylhydrazine) which possess mutagenic and genotoxic activ-ity. Subsequent test-object treatment with tinctures and UDMH significantly decrease the frequency of induced aberrant cells and number of chromosomal aberrations (p<0.05). In case of both mutagens, the rate of mutagenesis inhibition depended both on the order of tinctures and mutagen treatment and extracts concentration. The efficacy of antimutagenic activity of Mentha piperita L. and Thymus vulgaris L. tinctures was assessed with reduction factor (RF) which in both experiments exceeded 40% testifying to inhibition of MMS and UDMH induced mutagenesis. Data obtained indicate the antimutagenic ac-tivity of extracts of peppermint (Mentha piperita L.) and thyme (Thymus vulgaris L.) conditioned on the presence of biologically active compounds of various nature.Key words: medicinal herbs, biologically active compounds, induced mutagenesis, antimutagenic activity, chromosomal aberrations.

We have studied the expression of the E. coli ada and alkA genes and the luxA lux-operon gene in the plasmid and under the control of the alkA gene promoter methyl methanesulfonate (MMS) in the cells of deuterated and non-deuterated bacteria of the E. coli K12 MG1655 biosensor (pAlkA–lux) using the RT‑PCR method. The constitutively expressed rrsA 16S ribosome RNA gene was used as a reference. Deuteration of the bacterial culture was carried out in a medium containing 7.5% deuterium oxide (D2O). The numbers of PCR cycles in the cells of deuterated and non-deuterated bacteria were different; exponential emergence of the curve of dependence of the expression level of the studied genes on the number of PCR cycles occurred earlier during deuteration than in non-deuterated bacteria. This difference in the number of cycles (Сt) was 4, 6, and 9 for the luxA, alkA, and ada genes, respectively.

— The ability of the antibacterial agent dioxidine to generate the superoxide anion radical in E. coli cells, induce an SOS response, or cause DNA fragmentation or death of bacteria, as well as the effect of antioxidants on the processes listed, were studied using E. coli luminescent biosensors. Dioxidine induced the SOS response in the pColD-lux biosensor in concentrations typical for the most efficient induction of luminescence in a pSoxS-lux biosensor, the intensity of which depends on the amount of superoxide in the cell. Dioxidine in concentrations of more than 0.001 mol/L caused a decrease in the survival of bacterial cells, which is accompanied by the degradation of their DNA (as demonstrated by electrophoretic analysis). DNA degradation increased with an increase in the dioxidine concentration and decreased in the presence of the antioxidants glutathione and acetylcysteine. Antioxidants weakened the induction of the SOS response by dioxidine, as well as generation of superoxide radicals. Likely mechanisms of the formation of the hydroxyl radical during the reduction of the dioxidine NO group by bacterial reductases are discussed.

Ecological monitoring, including water resources, is included in a set of measures for the rational use and protection of the environment. Currently, the assessment of water resources' genotoxicity and mutagenicity is an essential component of ecological monitoring.This research aimed to investigate water's genotoxicity from the Esentai and Ulken Almaty rivers flowing in Almaty. It was established that the content of Fe, Cu, Co, Ni, Pb, and Cd in the Almaty rivers water does not exceed the maximum permissible concentration (MPC). In contrast, zinc content in the Esentai and Ulken Almaty rivers' water exceeded the MPC, respectively, by 1.1 and 7.7-folds, manganese – 2.1, and 1.9-folds. It was found that water samples from the Esentai and Ulken Almaty rivers showed a DNA-damaging effect on the studied cells (bone marrow, liver, kidneys, and spleen) of laboratory mice. In the cells of the studied organs in the experimental groups, the frequency of single-strand DNA breaks a statistically significant increase compared to the control group's animal. The genotoxic action's organospecificity of the studied river waters on laboratory mice was established. According to their sensitivity to water's genotoxic effect, experimental mice's organs can arrange in the following order: spleen and bone marrow> liver> kidneys. An increase in lipid peroxidation products was found in the laboratory mice' liver that drank water from the Esentai and Ulken Almaty rivers. Thus, the results of the physicochemical, molecular-genetic, and biochemical analysis of water on animal test objects indicate the presence in the investigated natural surface waters of chemicals with genotoxic and toxic activity. Keywords:surface waters; heavy metals; DNA comet assay, organ specificity, lipid peroxidation

The K -ratio between diadducts ( D ) and monoadducts ( M ) induced by 8-methoxypsoralen (8-MOP) in the DNA packed in the head of bacteriophage λ and in the DNA of pBR322 plasmid under UV irradiation (λ ≥ 320 nm) was measured. The probabilities of UVR excision repair of 8-MOP monoadducts ( P ) and of SOS repair of 8-MOP diadducts and monoadducts ( S and S m ) were determined. P was measured using an angular derivative of angelicin. It was demonstrated that P = 0.86. S and S m were determined using bacteriophage λ 11 treated with 8-MOP + UV (λ ≥ 320 nm) or 8-MOP + UV (λ ≥ 380 nm) and inoculated either onto bacteria pre-irradiated with short-wave UV light (λ = 254 nm) or onto bacteria with constitutive synthesis of the SOS regulon genes, as well as onto bacteria containing the pKM101 plasmid. In bacteriophage λ 11 , the level of W-reactivation (α) and the frequency of W-mutagenesis of clear mutations ( m ) were determined. It was demonstrated that 8-MOP diadducts (“crosslinks”) were repaired by the bacterial SOS system with the probability S = 0.28–0.29, and 8-MOP monoadducts were repaired by the bacterial SOS system with the probability S m = 0.41 only with the participation of the MucA’ 2 B enzyme, the genes for which were located in the conjugative plasmid pKM101.

Introduction: In this study, physicochemical, genotoxic, and mutagenic properties of water samples from 10 rivers of the Almaty region (Kazakhstan) were evaluated.Results: The results of the study demonstrated an increased level of mineralization and electrical conductivity that might be caused by the high concentration of dissolved mineral salts and ions such as Na+, K+, Ca2 +, Cl-, SO42-, HCO3-. The excess of Maximum Allowable Concentrations (MACs) for various heavy metals was revealed. The results of tests using the pXen7-lux biosensor showed toxic effects of river waters. At the same time, the studies involved lux biosensors pRecA-lux, pColD-lux, pSoxS-lux, pKatG-lux did not find any genotoxic and oxida-tive effects. However, toxicity and mutagenicity of the studied water samples was detected by using plant test (Allium cepa and Hordeum vulgare). Phytotoxic, cytotoxic (decrease in the mitotic index) and mutagenic (in-crease in the frequency of chromosomal aberrations) activity of the water samples was observed. The data of in vivo tests (Danio rerio) showed the high toxicity and teratogenicity of river waters for fish embryos at all stages of development.Conclusions: The results of this comprehensive study indicate that the contamination of the surface natural waters poses a threat to rivers dwellers and the human population in the rivers areas.(c) 2021 Ecological Society of China. Published by Elsevier B.V. All rights reserved.

Primary immunodeficiencies (PID) are a diverse group of genetic disorders caused by inadequate development and function of immune system. Identifying genetic etiology is important for genetic counselling and treatment decisions. Clinical relevance of genetic variants is a complex problem depending on gene-specific and variant specific genotype–phenotype interactions. To address this challenge, we aimed to characterize the pathogenic landscape of PID genes by combining the analysis of germline variations reported in ClinVar and HGMD® and identification of damaging variations available in dbSNP. We generated a joint ClinVar/HGMD database, which included 111,940 variants, among them 32,452 were classified as pathogenic/likely pathogenic. From a total of 5,415,794 bi- or multiallelic variants in PID genes recorded in dbSNP, we retrieved 38,291 high impact (HI) biallelic variants with presumably disruptive impact in the protein, of them 25,500 variants were not present in ClinVar/HGMD. Using a functional prediction algorithm, we additionally identified 28,507 deleterious and 56,016 neutral missense variants among dbSNP variants and created a collection of damaging and neutral variations in PID genes, not currently present in ClinVar/HGMD, with their allele frequencies and mappings to protein domains. The distribution of pathogenic variants from ClinVar/HGMD, HI variants and deleterious missense variants from dbSNP was analyzed in the context of hereditary pattern and gene specific metrics, such as pLI and haploinsufficiency. Our report summarized data on complex gene-specific variability in PID genes and might be useful for the identification of the most promising variants and gene regions for further study.

A comparative study of the genotoxic effects of methylmethanesulfonate (MMS) and epichlorohydrin (ECH) was performed using bacterial E. coli biosensors and the comet assay method in mice. ECH was shown to induce weaker SOS response and expression of the alk A gene in bacterial cells compared to MMS. In vivo experiments on mice using the comet assay method showed DNA-damaging activity of ECH in cells of the liver, kidneys, and lungs after 3 h of exposure, same as of MMS. The levels of DNA damage caused by ECH in these organs after exposure for 3 h were lower than for MMS. The genotoxic effect of ECH after 18 h of exposure was statistically significant only in a dose of 20 mg/kg in kidney cells.