Background/Objectives: New anti-tuberculosis compounds are needed to treat patients infected with multi- or extensively drug-resistant Mycobacterium tuberculosis strains. Studies based on spontaneous in vitro mutagenesis can provide insights into the possible modes of action and resistance mechanisms of such new compounds. We evaluated the primary response of M. tuberculosis in vitro to the action of new aroylhydrazones and nitrofuroylamides. Methods: The reference strain H37Rv was cultured on solid media with compounds at increased concentrations relative to MIC. Resistant clones were investigated using whole-genome sequencing and bioinformatics tools to assess the role and potential impact of identified mutations. Results: Some of the mutations are significant (based on in silico analysis), located in essential genes, and therefore of particular interest. Frameshift mutations were observed in (i) Rv2702/ppgK, which is associated with starvation-induced drug tolerance and persistence in mice, and (ii) Rv3696c/glpK, which has been described as a switch on/off mutation associated with drug tolerance. Nonsynonymous substitutions were found in Rv0506/mmpS2, which belongs to the Mmp protein family involved in transport and drug efflux, and in infB, encoding the translation initiation factor IF-2. Conclusions: The primary adaptation of M. tuberculosis to the selective pressure of the tested compounds is complex and multifaceted. It involves multiple unrelated genes and pathways linked to non-specific drug tolerance, efflux systems, or mechanisms counteracting oxidative stress.
Introduction. Helicobacter pylori infection, however, data on the mechanisms of metronidazole (MTZ) and levofloxacin (LVX) resistance in Russia remain scarce. and levofloxacin (LVX) in Russia. The aim of the study is to identify the determinants of resistance in clinical isolates of H. pylori to MTZ and LVX using whole-genome sequencing data. Materials and methods. A retrospective analysis of 43 H. pylori isolates obtained from adult patients (2014–2022) was conducted. Susceptibility to antibiotics was determined using the bacteriological disk diffusion method. Whole-genome sequencing of 43 H. pylori strains was performed using a DNBSEQ-G50 sequencer. Results. The evaluation of the phenotypic drug susceptibility test results showed that 11 isolates were susceptible to MTZ (MTZ-S), 31 were susceptible to LVX (LVX-S), while 32 isolates were resistant to MTZ (MTZ-R), and 12 were resistant to LVX (LVX-R). To identify the association between phenotypic and genotypic resistance, an analysis of nucleotide substitutions in the gyrA, gyrB, rdxA, frxA, fdxB and fur genes was conducted. Of all the mutations identified in the gyrA and gyrB genes, only D91/GNY in the gyrA gene was associated with phenotypic resistance to LVX and was found in 4/12 (33.3%) of the isolates (p 0.05). The combined mutation D91G/N/Y+N87K in the gyrA gene was detected in 6/12 (50.0%) of LVX-R isolates (p 0.001). Point mutations in the rdxA gene were detected in 21.9% (7/32) of MTZ-R isolates, leading to a frameshift or premature termination of protein synthesis. None of the mutations in the frxA, fur and fdxB genes were associated with H. pylori resistance to MTZ. Conclusion. Based on the results of whole-genome sequencing of Russian clinical isolates of H. pylori, the detection of the combined mutation D91G/N/Y+N87K in the gyrA gene can serve as a predictor of the phenotypic resistance of H. pylori to levofloxacin.
Type 2 diabetes (T2D) is a chronic metabolic disorder with an estimated prevalence of over 422 million individuals affected globally. Since the advent of genomics, numerous studies have been conducted to elucidate T2D pathogenetic mechanisms and define genetic loci affecting T2D susceptibility. Transcriptomic studies, including bulk and single-cell RNA sequencing, play an important role both in discerning molecular mechanisms of the disease and in identifying potential T2D biomarkers. In this study, we performed bulk RNA-seq of whole blood of nine T2D patients and nine control subjects and performed meta-analysis of these data with seven publicly available blood RNA-seq datasets of T2D patients. Our analysis showed that the changes in the gene expression between different studies show very low concordance; moreover, a substantial number of differentially expressed genes (DEGs) was identified in only three out of eight datasets, with only five DEGs-FBLN2, TPCN1, PC, SHANK1, and PLD4-identified in all three of those datasets. Nevertheless, cross-study meta-analysis identified a broad set of 2065 DEGs, including 713 genes that have not been identified in any of the source studies. These genes showed a significant enrichment of GO terms indicating neutrophil activation and proliferation and included several genes that have not been implicated in type 2 diabetes previously. Taken together, our study highlights challenges associated with biomarker discovery from blood transcriptomics in T2D and suggests novel genes that may be considered as such biomarkers.
Population allele frequency is crucially important for accurate interpretation of known and novel variants in medical genetics. Recently, several large allele frequency databases, such as the Genome Aggregation Database (gnomAD), have been created to serve as a global reference for such studies. However, frequencies of many rare alleles vary dramatically between populations, and population-specific allele frequency is often more informative than the global one. Many countries and regions, including Russia, remain poorly studied from the genetic perspective. Here, we report the first successful attempt to integrate genetic information between major medical genetic laboratories in Russia. We construct RUSeq, an open, large-scale reference set of genetic variants by analyzing 7452 exome samples collected in two major Russian cities-Moscow and St. Petersburg. An similar to 10-fold increase in sample size compared to previous studies allowed us to characterize extensive genetic diversity within the admixed Russian population with contributions from several major ancestral groups. We highlight 51 known pathogenic variants that are overrepresented in Russia compared to other European countries. We also identify several dozen high-impact variants that are present in healthy donors despite being annotated as pathogenic in ClinVar and falling within genes associated with autosomal dominant disorders.
Clarithromycin (CLR) is currently a key antibiotic for Helicobacter pylori infection treatment, however, the data on CLR resistance patterns in Russia are missing. Here, we applied WGS-based approach to H. pylori clinical isolates from Russia to comprehensively investigate sequence variation, identify putative markers of CLR resistance and correlate them with phenotypic susceptibility testing. The phenotypic susceptibility of 44 H. pylori isolates (2014-2022) to CLR was determined by disc diffusion method: 23 isolates were CLR-resistant and 21-CLR-susceptible. All isolates were subjected to WGS and submitted to GenBank. Based on complete sequence analysis, we showed that among all sequence variants, the combination of mutations A2146G/A2147G in the 23S rRNA gene is the most reliable for prediction of phenotypic susceptibility. For the first time, the average number of mutations in 106 virulence-associated genes between resistant and susceptible groups were compared. Moreover, this study presents the first WGS insight into genetic diversity of H. pylori in Russia with a particular focus on the molecular basis of drug resistance: the novel mutations were described as potential markers for the resistance development. Of these, the most prominent was a frameshift deletion (252:CGGGT) in HP0820 coding region, which is a good candidate for further investigation.
The temperature-sensitive Drosophila mutant agnts3 exhibits the restoration of learning defects both after heat shock (HS) and under hypomagnetic conditions (HMC). Previously, agnts3 was shown to have an increased level of LIM kinase 1 (LIMK1). However, its limk1 sequence did not significantly differ from that of the wild-type strain Canton-S (CS). Here, we performed whole-genome and poly(A)-enriched transcriptome sequencing of CS and agnts3 males normally, after HMC, and after HS. Several high-effect agnts3-specific mutations were identified, including MED23 (regulation of HS-dependent transcription) and Spn42De, the human orthologs of which are associated with intellectual disorders. Pronounced interstrain differences between the transcription profiles were revealed. Mainly, they included the genes of defense and stress response, long non-coding RNAs, and transposons. After HS, the differences between the transcriptomes became less pronounced. In agnts3, prosalpha1 was the only gene whose expression changed after both HS and HMC. The normal downregulation of prosalpha1 and Spn42De in agnts3 was confirmed by RT-PCR. Analysis of limk1 expression did not reveal any interstrain differences or changes after stress. Thus, behavioral differences between CS and agnts3 both under normal and stressed conditions are not due to differences in limk1 transcription. Instead, MED23, Spn42De, and prosalpha1 are more likely to contribute to the agnts3 phenotype.
Orthopedia homeobox ( OTP ) gene encodes a homeodomain-containing transcription factor involved in brain development. OTP is mapped to human chromosome 5q14.1. Earlier we described transcription in the second intron of this gene in wide variety of tumors, but among normal tissues only in testis. In GeneBank these transcripts are presented by several 300-400 nucleotides long AI267901-like ESTs.We assumed that AI267901-like ESTs belong to longer transcript(s). We used the Rapid Amplification of cDNA Ends (RACE) approach and other methods to find the full-length transcript. The found transcript was 2436 nucleotides long polyadenylated sequence in antisense to OTP gene. The corresponding gene consisted of two exons separated by an intron of 2961 bp long. The first exon was found to be 91 bp long and located in the third exon of OTP gene. The second exon was 2345bp long and located in the second intron of OTP gene.The search of possible open reading frames (ORFs) showed the lack of significant ORFs. We have shown the expression of new gene in many human tumors and only in one sampled normal testis. The data suggest that we discovered a new antisense cancer-testis sequence OTP - AS1 ( OTP - antisense RNA 1), which belongs to long noncoding RNAs (lncRNAs). According to our findings we assume that OTP-AS1 and OTP genes may be the CT-coding gene/CT-ncRNA pair involved in regulatory interactions.Author summary Previously, long non-coding RNAs (lncRNAs) were considered as genetic “noise”. However, it was later shown that only 2% of genomic transcripts have a protein-coding ability. Non-coding RNA is divided into short non-coding RNAs (20-200 nucleotides) and long noncoding RNAs (200-100,000 nucleotides). Genes encoding lncRNA often overlap or are adjacent to protein-coding genes, and localization of this kind is beneficial in order to regulate the transcription of neighboring genes. Studies have shown that of lncRNAs play many roles in the regulation of gene expression. New evidence indicates that dysfunctions of lncRNAs are associated with human diseases and cancer.In our study we found a new cancer-testis long noncoding RNA ( OTP-AS1 ), which is an antisense of protein-coding cancer-testis gene ( OTP ). Thus, OTP-AS1 and OTP genes may be the CT-coding gene/CT-ncRNA pair involved in regulatory interactions. This is supported by the similar profile of their expression. OTP-AS1 may be of interest as a potential diagnostic marker of cancer or a potential target for cancer therapy.Part of OTP-AS1 gene (5’-end of the second exon) is evolutionary younger than the rest of gene sequence and is less conservative. This links OTP-AS1 gene with so-called TSEEN (tumor-specifically expressed, evolutionary novel) genes described by the authors in previous papers.
The intricate relationships between parasites and hosts encompass a wide range of levels, from molecular interactions to population dynamics. Parasites influence not only the physiological processes in the host organism, but also the entire ecosystem, affecting mortality of individuals, the number of offspring through parasitic castration, and matter and energy cycles. Understanding the molecular mechanisms that govern host-parasite relationships and their impact on host physiology and environment remains challenging. In this study, we analyzed how infection with Microphallus trematodes affects the metabolome of two Littorina snail species inhabiting different intertidal zone shore levels. We applied non-targeted GC-MS-based metabolomics to analyze biochemical shifts induced by trematode infection in a host organism. We have identified changes in energy, amino acid, sugar, and lipid metabolism. In particular, we observed intensified amino acid catabolism and nitrogenous catabolites (glutamine, urea) production. These changes primarily correlated with infection and interspecies differences of the hosts rather than shore level. The changes detected in the host metabolism indicate that other aspects of life may have been affected, both within the host organism and at a supra-organismal level. Therefore, we explored changes in microbiota composition, deviations in the host molluscs behavior, and acetylcholinesterase activity (ACE, an enzyme involved in neuromuscular transmission) in relation to infection. Infected snails displayed changes in their microbiome composition. Decreased ACE activity in snails was associated with reduced mobility, but whether it is associated with trematode infection remains unclear. The authors suggest a connection between the identified biochemical changes and the deformation of the shell of molluscs, changes in their behavior, and the associated microbiome. The role of parasitic systems formed by microphallid trematodes and Littorina snails in the nitrogen cycle at the ecosystem level is also assumed.
The aim of this study is to describe the phenotypic and genetic properties of oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) isolates and their beta-lactam resistant derivatives obtained after selection with oxacillin. A collection of hospital- (HA-) and community-acquired (CA-) MRSA was screened for oxacillin susceptibility. Antibiotic susceptibility testing, population analysis profile (PAP), mecA expression analysis, and whole genome sequencing (WGS) were performed for 60 mecA-positive OS-MRSA isolates. Twelve high-level beta-lactam resistant derivatives selected during PAP were also subjected to WGS. OS-MRSA were more prevalent among CA-MRSA (49/205, 24
Agrobacterium (Rhizobium)-mediated transformation leads to the formation of crown galls or hairy roots on infected plants. These effects develop due to the activity of T-DNA genes, gathered on a big plasmid, acquired from agrobacteria during horizontal gene transfer. However, a lot of plant species are known to contain such sequences, called cellular T-DNAs (cT-DNAs), and maintain normal phenotypes. Some of the genes remain intact, which leads to the conclusion of their functional role in plants. In this study, we present a comprehensive analysis of the cT-DNAs in the Nicotiana noctiflora Hook. genome, including gene expression and opine identification. Deep sequencing of the Nicotiana noctiflora genome revealed the presence of two different cT-DNAs, NnT-DNA1 and NnT-DNA2, which contain the intact genes iaaM, iaaH, acs, orf13, orf13a, and orf14. According to the expression analysis results, all these genes are most active in roots in comparison with other organs, which is consistent with data on cT-DNA gene expression in other plant species. We also used genetic engineering approaches and HPTLC and HPLC-MS methods to investigate the product of the acs gene (agrocinopine synthase), which turned out to be similar to agrocinopine A. Overall, this study expands our knowledge of cT-DNAs in plants and brings us closer to understanding their possible functions. Further research of cT-DNAs in different species and their functional implications could contribute to advancements in plant genetics and potentially unveil novel traits with practical applications in agriculture and other fields.
Symbiotic microorganisms may provide their hosts with abilities critical to their occupation of microhabitats. Gut (intestinal) bacterial communities aid animals to digest substrates that are either innutritious or toxic, as well as support their development and physiology. The role of microbial communities associated with sibling species in the hosts' adaptation remains largely unexplored. In this study, we examined the composition and plasticity of the bacteriomes in two sibling intertidal gastropod species, Littorina fabalis and L. obtusata, which are sympatric but differ in microhabitats. We applied 16S rRNA gene metabarcoding and shotgun sequencing to describe associated microbial communities and their spatial and temporal variation. A significant drop in the intestinal bacteriome diversity was revealed during the cold season, which may reflect temperature-related metabolic shifts and changes in snail behavior. Importantly, there were significant interspecies differences in the gut bacteriome composition in summer but not in autumn. The genera Vibrio, Aliivibrio, Moritella and Planktotalea were found to be predominantly associated with L. fabalis, while Granulosicoccus, Octadecabacter, Colwellia, Pseudomonas, Pseudoalteromonas and Maribacter were found to be mostly associated with L. obtusata. Based on these preferential associations, we analyzed the metabolic pathways' enrichment. We hypothesized that the L. obtusata gut bacteriome contributes to decomposing algae and detoxifying polyphenols produced by fucoids. Thus, differences in the sets of associated bacteria may equip their closely phylogenetically related hosts with a unique ability to occupy specific micro-niches.
In this study, we investigated the abundance and diversity of bacteria in the digestive tract of the bivalve mollusks Unio pictorum after 30-day exposure in experimental cages and field-collected gastropod mollusk Radix balthica in the eastern Gulf of Finland, Baltic Sea. Contamination of water and sediments with petroleum hy-drocarbons had a significant impact on the intestinal bacterial community of mollusks stimulating the growth of hydrocarbon-oxidizing bacteria. The abundance of the intestinal hydrocarbon-oxidizing bacteria correlated with the concentration of the total hydrocarbons in the water of the coastal sites in the Gulf, where the mollusks were exposed. Metagenomic analysis revealed significant differences in the intestinal microbial community compo-sition between polluted and unpolluted sites. The increased abundance of members of the phylum Gammapro-teobacteria, including species of Aeromonas, Acinetobacter, Arenimonas, Pseudomonas, Rheinheimera, and Shewanella, and Bacteroidetes (Flavobacterium and Pedobacter) in the intestinal tracts of mollusks Unio pictorum were found at hydrocarbon-contaminated site: therefore, these bacteria are key players in the adaptation of intestinal community to this kind of pollution and hydrocarbon degradation. Our study suggests that hydrocarbon-oxidizing bacteria have the potential as a sensitive bioindicator for the further monitoring and ecological assessment of marine ecosystems.
The COVID-19 pandemic has drawn the attention of many researchers to the interaction between pathogen and host genomes. Over the last two years, numerous studies have been conducted to identify the genetic risk factors that predict COVID-19 severity and outcome. However, such an analysis might be complicated in cohorts of limited size and/or in case of limited breadth of genome coverage. In this work, we tried to circumvent these challenges by searching for candidate genes and genetic variants associated with a variety of quantitative and binary traits in a cohort of 840 COVID-19 patients from Russia. While we found no gene- or pathway-level associations with the disease severity and outcome, we discovered eleven independent candidate loci associated with quantitative traits in COVID-19 patients. Out of these, the most significant associations correspond to rs1651553 in MYH14 p = 1.4 × 10−7), rs11243705 in SETX (p = 8.2 × 10−6), and rs16885 in ATXN1 (p = 1.3 × 10−5). One of the identified variants, rs33985936 in SCN11A, was successfully replicated in an independent study, and three of the variants were found to be associated with blood-related quantitative traits according to the UK Biobank data (rs33985936 in SCN11A, rs16885 in ATXN1, and rs4747194 in CDH23). Moreover, we show that a risk score based on these variants can predict the severity and outcome of hospitalization in our cohort of patients. Given these findings, we believe that our work may serve as proof-of-concept study demonstrating the utility of quantitative traits and extensive phenotyping for identification of genetic risk factors of severe COVID-19.
Introduction: Floating Harbor syndrome (FHS) is an extremely rare disorder, with slightly more than a hundred cases reported worldwide. FHS is caused by heterozygous mutations in the SRCAP gene; however, little is known about the pathogenesis of FHS or the effectiveness of its treatment.Methods: Whole-exome sequencing (WES) was performed for the definitive molecular diagnosis of the disease. Identified variants were validated using Sanger sequencing. In addition, systematic literature and public data on genetic variation in SRCAP and the effects of growth hormone (GH) treatment was conducted.Results: We herein report the first case of FHS in the Russian Federation. The male proband presented with most of the typical phenotypic features of FHS, including short stature, skeletal and facial features, delayed growth and bone age, high pitched voice, and intellectual impairment. The proband also had partial growth hormone deficiency. We report the history of treatment of the proband with GH, which resulted in modest improvement in growth prior to puberty. WES revealed a pathogenic c.7466C>G (p.Ser2489*) mutation in the last exon of the FHS-linked SRCAP gene. A systematic literature review and analysis of available genetic variation datasets highlighted an unusual distribution of pathogenic variants in SRCAP and confirmed the lack of pathogenicity for variants outside of exons 33 and 34. Finally, we suggested a new model of FHS pathogenesis which provides possible basis for the dominant negative nature of FHS-causing mutations and explains limited effects of GH treatment in FHS.Conclusion: Our findings expand the number of reported FHS cases and provide new insights into disease genetics and the efficiency of GH therapy for FHS patients.
Although high altitude training has been increasingly popular among endurance athletes, the molecular and cellular bases of this adaptation remain poorly understood. We aimed to define the underlying physiological changes and screen for potential biomarkers of adaptation using transcriptional profiling of whole blood. Seven elite female speed skaters were profiled on the 18th day of high-altitude adaptation. Whole blood RNA-seq before and after an intense 1 h skating bout was used to measure gene expression changes associated with exercise. In order to identify the genes specifically regulated at high altitudes, we have leveraged the data from eight previously published microarray datasets studying blood expression changes after exercise at sea level. Using cell type-specific signatures, we were able to deconvolute changes of cell type abundance from individual gene expression changes. Among these were PHOSPHO1, with a known role in erythropoiesis, and MARC1 with a role in endogenic NO metabolism. We find that platelet and erythrocyte counts uniquely respond to altitude exercise, while changes in neutrophils represent a more generic marker of intense exercise. Publicly available data from both single cell atlases and exercise-related blood profiling dramatically increases the value of whole blood RNA-seq for the dynamic evaluation of physiological changes in an athlete’s body.
Population allele frequency is crucially important for accurate interpretation of known and novel variants in medical genetics. Recently, several large allele frequency databases, such as Genome Aggregation Database (gnomAD), have been created to serve as a global reference for such studies. However, frequencies of many rare alleles vary dramatically between populations, and population-specific allele frequency is often more informative than the global one. Many countries and regions, including Russia, remain poorly studied from the genetic perspective. Here, we report the first successful attempt to integrate genetic information between major medical genetic laboratories in Russia. We construct an open, large-scale reference set of genetic variants by analyzing 7,492 exome samples collected in two major Russian cities of Moscow and St. Petersburg. An approximately tenfold increase in sample size compared to previous studies allowed us to identify genetically distinct clusters of individuals within an admixed population of Russia. We highlight 47 known pathogenic variants that are overrepresented in Russia compared to other European countries. We also identify several dozen high-impact variants that are present in healthy donors despite either being annotated as pathogenic in ClinVar or falling within genes associated with autosomal dominant disorders. The constructed database of genetic variant frequencies in Russia has been made available to the medical genetics community through a variant browser available at . ### Competing Interest Statement Analysis of NGS data and the construction of the catalogue of allele frequencies was funded jointly by the Genetics and Reproductive Medicine Center GENETICO Ltd. and CerbaLab Ltd. according to the partnership agreement dated 25.10.2021. All rights to the data and resources generated during the work are reserved to the aforementioned parties. ### Funding Statement The work was supported by the Systems Biology Fellowship to Y.A.B. the Presidential Fellowship for Young Scientists (grant no. SP-4503.2021.4) to Y.A.B., and D.O. Ott Research Institute of Obstetrics, Gynaecology and Reproductology, project 558-2019-0012 (AAAA-A19119021290033-1) of FSBSI. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was approved by the ethics committee of the D.O. Ott Institute of Obstetrics, Gynecology, and Reproductology (protocol 114 from 14 December 2021) and conducted in accordance with the Declaration of Helsinki. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Variant frequency level data produced in the present study are available via form submission available at ruseq.ru.
Thousands of yeast genomes have been sequenced with both traditional and long-read technologies, and multiple observations about modes of genome evolution for both wild and laboratory strains have been drawn from these sequences. In our study, we applied Oxford Nanopore and Illumina technologies to assemble complete genomes of two widely used members of a distinct laboratory yeast lineage, the Peterhof Genetic Collection (PGC), and investigate the structural features of these genomes including transposable element content, copy number alterations, and structural rearrangements. We identified numerous notable structural differences between genomes of PGC strains and the reference S288C strain. We discovered a substantial enrichment of mid-length insertions and deletions within repetitive coding sequences, such as in the SCH9 gene or the NUP100 gene, with possible impact of these variants on protein amyloidogenicity. High contiguity of the final assemblies allowed us to trace back the history of reciprocal unbalanced translocations between chromosomes I, VIII, IX, XI, and XVI of the PGC strains. We show that formation of hybrid alleles of the FLO genes during such chromosomal rearrangements is likely responsible for the lack of invasive growth of yeast strains. Taken together, our results highlight important features of laboratory yeast strain evolution using the power of long-read sequencing.