Increased Copy Number Research Articles

Partial unidirectional translocation from 5AL to 7BS leads to dense spike in an EMS-induced wheat mutant.

As the inflorescence of wheat, spike architecture largely determines grain productivity. Dissecting the genetic basis for the spike morphology of wheat can contribute to the designation of ideal spike morphology to improve grain production. The present study characterizes a dense spike1 (ds1) mutant, derived from Nongda3753, induced by EMS treatment, which exhibits a dense spike and reduced plant height. Through bulked segregant analysis sequencing (BSA-Seq) of two segregating populations, ds1 was mapped to the short arm of chromosome 7B. Further genotypic and phenotypic analyses of the residual heterozygous lines from F3 to F6 of Yong3002×ds1 revealed that there was a 0-135Mb deletion in chromosome 7B associated with the dense spike phenotype. The reads count analysis of the two bulks in BSA-Seq, along with the cytological analysis of ds1, ND3753, NIL-ds1 and NIL-Y3002, confirmed that the partial unidirectional translocation of 5AL (543-713Mb) to 7BS (0-135Mb) exists in ds1. This translocation led to an increase in both copy number and expression of the Q gene, which is one of the reasons for the dense spike phenotype observed in ds1. Partial unidirectional translocation from 5AL to 7BS was identified in the EMS-induced mutant ds1, which exhibits dense spike phenotype. This research illustrates the effect of one chromosome structure variation on wheat spike morphology, and provides new materials with several chromosome structure variations for future wheat breeding.

High mitochondrial DNA levels accelerate lung adenocarcinoma progression.

Lung adenocarcinoma is a common aggressive cancer and a leading cause of mortality worldwide. Here, we report an important in vivo role for mitochondrial DNA (mtDNA) copy number during lung adenocarcinoma progression in the mouse. We found that lung tumors induced by KRASG12D expression have increased mtDNA levels and enhanced mitochondrial respiration. To experimentally assess a possible causative role in tumor progression, we induced lung cancer in transgenic mice with a general increase in mtDNA copy number and found that they developed a larger tumor burden, whereas mtDNA depletion in tumor cells reduced tumor growth. Immune cell populations in the lung and cytokine levels in plasma were not affected by increased mtDNA levels. Analyses of large cancer databases indicate that mtDNA copy number is also important in human lung cancer. Our study thus reports experimental evidence for a tumor-intrinsic causative role for mtDNA in lung cancer progression, which could be exploited for development of future cancer therapies.

Confirmation of Glyphosate Resistance in Annual Bluegrass (Poa annua) via EPSPS Duplication in a Soybean and Rice Rotation

Abstract Annual bluegrass (Poa annua L.) populations in turfgrass have evolved resistance to several herbicides in the United States (US), but there has been no confirmed resistance from an agricultural field. Recently, glyphosate failed to control a P. annua population found in a field in a soybean [(Glycine max (L.) Merr.] and rice (Oryza sativa L.) rotation in Poinsett County, Arkansas. The present study focused on determining the sensitivity of a putatively-resistant accession (R1) to glyphosate compared with two susceptible accessions (S1 and S2). The experiments included a dose-response study, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene copy number and expression analysis, and assessment of mutations in EPSPS. Based on the dose-response analysis, R1 required 1,038 g ae ha-1 of glyphosate to cause 50% biomass reduction, whereas S1 and S2 only required 148.2 g and 145.5 g ae ha-1, respectively. The resistant index (RI) was approximately 7-fold relative to the susceptible accessions. Real-time polymerase chain reaction data revealed at least a 15-fold increase in the EPSPS copy number in R1, along with a higher gene expression. No mutations in EPSPS were found. Gene duplication was identified as the main mechanism conferring resistance in R1. The research presented here reports the first incidence of glyphosate resistance in P. annua from an agronomic field crop situation in the US.

Diversity and Evolution of NLR Genes in Citrus Species.

NLR genes are crucial components of the effector-triggered immunity (ETI) system, responsible for recognizing pathogens and initiating immune responses. Although NLR genes in many plant species have been extensively studied, the diversity of NLR genes in citrus remains largely unknown. Our analysis revealed significant variations in the copy numbers of NLR genes among these species. Gene duplication and recombination were identified as the major driving forces behind this diversity. Additionally, horizontal gene transfer (HGT) emerged as the principal mechanism responsible for the increase in NLR gene copy number in A. buxifolia. The citrus NLR genes were classified into four categories: TIR-NBS-LRR (TNL), CC-NBS-LRR (CNL), RPW8-NBS-LRR (RNL), and NL. Our findings indicate that TNL, RNL, and CNL genes originated from NL genes through the acquisition of TIR and RPW8 domains, along with CC motifs, followed by the random loss of corresponding domains. Phylogenetic analysis suggested that citrus NLR genes originated alongside the species and underwent adaptive evolution, potentially playing crucial roles in the global colonization of citrus. This study provides important insights into the diversity of citrus NLR genes and serves as a foundational dataset for future research aimed at breeding disease-resistant citrus varieties.

Prognostic modeling of hepatocellular carcinoma based on T-cell proliferation regulators: a bioinformatics approach.

The prognostic value and immune significance of T-cell proliferation regulators (TCRs) in hepatocellular carcinoma (HCC) have not been previously reported. This study aimed to develop a new prognostic model based on TCRs in patients with HCC. This study used The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) and International Cancer Genome Consortium-Liver Cancer-Riken, Japan (ICGC-LIRI-JP) datasets along with TCRs. Differentially expressed TCRs (DE-TCRs) were identified by intersecting TCRs and differentially expressed genes between HCC and non-cancerous samples. Prognostic genes were determined using Cox regression analysis and were used to construct a risk model for HCC. Kaplan-Meier survival analysis was performed to assess the difference in survival between high-risk and low-risk groups. Receiver operating characteristic curve was used to assess the validity of risk model, as well as for testing in the ICGC-LIRI-JP dataset. Additionally, independent prognostic factors were identified using multivariate Cox regression analysis and proportional hazards assumption, and they were used to construct a nomogram model. TCGA-LIHC dataset was subjected to tumor microenvironment analysis, drug sensitivity analysis, gene set variation analysis, and immune correlation analysis. The prognostic genes were analyzed using consensus clustering analysis, mutation analysis, copy number variation analysis, gene set enrichment analysis, and molecular prediction analysis. Among the 18 DE-TCRs, six genes (DCLRE1B, RAN, HOMER1, ADA, CDK1, and IL1RN) could predict the prognosis of HCC. A risk model that can accurately predict HCC prognosis was established based on these genes. An efficient nomogram model was also developed using clinical traits and risk scores. Immune-related analyses revealed that 39 immune checkpoints exhibited differential expression between the high-risk and low-risk groups. The rate of immunotherapy response was low in patients belonging to the high-risk group. Patients with HCC were further divided into cluster 1 and cluster 2 based on prognostic genes. Mutation analysis revealed that HOMER1 and CDK1 harbored missense mutations. DCLRE1B exhibited an increased copy number, whereas RAN exhibited a decreased copy number. The prognostic genes were significantly enriched in tryptophan metabolism pathways. This bioinformatics analysis identified six TCR genes associated with HCC prognosis that can serve as diagnostic markers and therapeutic targets for HCC.

Adaptive copy number variations of ancient prokaryotic genes in marine fish colonization

During extensive evolution, higher eukaryotes have acquired numerous prokaryotic genes, some of which have experienced adaptive copy number variations (CNVs) in response to changing environments. The specific contribution of ancient prokaryotic genes to the evolutionary dynamics of marine fish remains unclear. In this study, we investigated ancient prokaryotic genes in 33 freshwater and 14 non-freshwater fish species. Non-freshwater fish exhibited a higher proportion of these genes (25.84 %) compared to freshwater fish (17.66 %), though functional categories showed similarity, suggesting genetic conservation. Comprehensive CNV analysis identified 24 genes with significantly higher copy numbers in non-freshwater fish, enriched in glycerolipid metabolism, immune regulation, and catechol O-methyltransferase activity. Eight of these genes displayed increased copy numbers in marine populations compared to Asian freshwater populations. These findings indicate that CNVs in genes related to glycerolipid metabolism, immune regulation, and methyltransferase activity may play crucial roles in marine adaptation at global and regional evolutionary scales.

Microbial rrn copy number is associated with soil C: N ratio and pH under long-term fertilization

Soil microbial life-history strategies, as indicated by rRNA operon (rrn) copy numbers, strongly influence agro-ecosystem functioning. Long-term N fertilization causes strong and lasting changes in soil properties, yet its impact on microbial strategies remains largely unexplored. Using long-term field experiments across three agro-ecosystems, we consistently found that N fertilization strongly decreased soil C: N ratio and pH, further increasing the community-level rrn copy number, including both average rrn copy number and total 16S rRNA copy number. Soil C: N stoichiometry balanced by N supplement favored the growth of N-dependent copiotrophic species containing high rrn copy numbers (an average of 2.5) and increased their network connections, predominantly contributing to community-level rrn copy number increase. Decreased soil pH caused by N fertilization also favored the growth of some species whose abundances negatively correlated with pH, partially contributing to the community-level rrn copy number increase. By examining the genomes of two dominant species, we found that microorganisms with a higher rrn copy number (6), e.g., Streptomyces scabiei, possessed more genes related to C and N transport and metabolism. In contrast, the Mycobacterium simiae with a lower rrn copy number (1) has more genes associated with secondary metabolite biosynthesis and lipid transport and metabolism. Our finding challenges the concept of microbial life-strategy regulation solely by nutrient availability, highlighting the important contributions of soil stoichiometric balance and pH to microbial strategies in agro-ecosystems under long-term N inputs.

1,2-Dicinnamoyl-sn-glycero-3-phosphocholine Improves Insulin Sensitivity and Upregulates mtDNA-Encoded Genes in Insulin-Resistant 3T3-L1 Adipocytes: A Preliminary Study.

Insulin resistance is a condition characterized by a reduced biological response to insulin. It is one of the most common metabolic diseases in modern civilization. Numerous natural substances have a positive effect on metabolism and energy homeostasis including restoring the proper sensitivity to insulin. There may be several possible mechanisms of action. In the present study, we elucidated two natural compounds with an impact on insulin signaling in IR adipocytes involving mitochondria. Mature 3T3-L1 adipocytes with artificially induced insulin resistance by palmitic acid (16:0) were used for the study. Cinnamic acid and 1,2-dicinnamoyl-sn-glycero-3-phosphocholin (1,2-diCA-PC) were tested at three concentrations: 25 μM, 50 μM, and 125 μM. The number of mitochondria and the expression of genes encoded by mtDNA were elucidated in control and experimental cells. Experimental cells treated with 1,2-diCA-PC displayed increased insulin-stimulated glucose uptake in a dose-dependent manner, accompanied by an increase in mtDNA copy number. Moreover, in experimental cells treated with 1,2-diCA-PC at a concentration of 125 μM, a significant increase in the expression level of all analyzed genes encoded by mtDNA compared to control cells was observed. Our study showed a relationship between improved cellular sensitivity to insulin by 1,2-diCA-PC and an increase in the number of mitochondria and expression levels of genes encoded by mtDNA. To summarize, the results suggest the therapeutic potential of cinnamic acid derivative 1,2-diCA-PC to enhance the insulin sensitivity of adipocytes.

Phagemid-based capsid system for CRISPR-Cas13a antimicrobials targeting methicillin-resistant Staphylococcus aureus

In response to the escalating antibiotic resistance in multidrug-resistant pathogens, we propose an innovative phagemid-based capsid system to generate CRISPR-Cas13a-loaded antibacterial capsids (AB-capsids) for targeted therapy against multidrug-resistant Staphylococcus aureus. Our optimized phagemid system maximizes AB-capsid yield and purity, showing a positive correlation with phagemid copy number. Notably, an 8.65-fold increase in copy number results in a 2.54-fold rise in AB-capsid generation. Phagemids carrying terL-terS-rinA-rinB (prophage-encoded packaging site genes) consistently exhibit high packaging efficiency, and the generation of AB-capsids using lysogenized hosts with terL-terS deletion resulted in comparatively lower level of wild-type phage contamination, with minimal compromise on AB-capsid yield. These generated AB-capsids selectively eliminate S. aureus strains carrying the target gene while sparing non-target strains. In conclusion, our phagemid-based capsid system stands as a promising avenue for developing sequence-specific bactericidal agents, offering a streamlined approach to combat antibiotic-resistant pathogens within the constraints of efficient production and targeted efficacy.

C-type lectins containing an immunoglobulin domain have an anti-WSSV function in Procambarus clarkii

Crayfish, as an invertebrate, cannot produce specific antibodies to defend against viruses. However, they have their own survival strategy to protect themselves from virus infection. In this study, two C-type lectins (CTLs) containing one immunoglobulin (IG) domain (PcIgLec2 and PcIgLec3) were characterized from Procambarus clarkii. PcIgLec2 and PcIgLec3 were widely expressed in various tissues, and their expression levels in the intestine were upregulated by white spot syndrome virus (WSSV). Knockdown of PcIgLec2 or PcIgLec3 resulted in a significant increase in VP28 expression and WSSV copy number, and injection of recombinant PcIgLec2 (rPcIgLec2) or recombinant PcIgLec3 (rPcIgLec3) protein could reduce VP28 expression and WSSV copy number. Further investigation indicated that the IG domain of PcIgLec2 or PcIgLec3 inhibited WSSV replication, whereas their carbohydrate recognition domain (CRD) had no substantial effect on WSSV replication. WSSV binding assays showed that rPcIgLec2, rPcIgLec3, rPcCRD2, and rPcCRD3 had the ability to bind to WSSV. However, their IG domain could not bind to WSSV. In conclusion, the two CTLs with an IG domain participated in antiviral innate immunity. Their CRD was responsible for WSSV binding, and their IG domain played negative roles in WSSV replication.

Aneuploidy of Specific Chromosomes is Beneficial to Cells Lacking Spindle Checkpoint Protein Bub3.

Accurate chromosome segregation is crucial for the proper development of all living organisms. Errors in chromosome segregation can lead to aneuploidy, characterized by an abnormal number of chromosomes, which generally impairs cell survival and growth. However, under certain stress conditions, such as in various cancers, cells with specific mutations and extra copies of advantageous chromosomes exhibit improved survival and proliferation. In our study, we discovered that cells lacking the spindle checkpoint protein Bub3 became aneuploid, retaining specific chromosomes. This finding was unexpected because although bub3 Δ cells have a higher rate of chromosome mis-segregation, they were not thought to maintain an aneuploid karyotype. We investigated whether the increased copy number of specific genes on these acquired chromosomes offered a benefit to Bub3-deficient cells. Our results revealed that several genes involved in chromosome segregation and cell cycle regulation prevented the gain of chromosomes upon Bub3-depletion, suggesting that these genes confer a survival advantage. Overall, our study demonstrates that cells lacking Bub3 selectively retain specific chromosomes to increase the copy number of genes that promote proper chromosome segregation.

CDK4 gene copy number increase and concurrent genetic changes in acral melanoma of a Chinese cohort

Acral melanoma (AM) is the most common subtype of melanoma in Asian population. Abnormalities in the p16-cyclin D1-CDK4 signalling pathway play a crucial role in the development and progression of AM. However, the alterations of CDK4 gene copy number in AM are underreported. In this study, we investigated CDK4 gene copy number and concurrent molecular changes in a Chinese cohort with AM, in aim of exploring CDK4 gene alterations and its significance in AM. We examined copy number alterations of CDK4 with fluorescence in situ hybridisation (FISH) in 31 patients with AM. Six patients with CDK4 high-level copy number increase were examined by next-generation sequencing to detect concurrent molecular changes. Using FISH, 12 (12/31, 38.7%) cases showed CDK4 copy number increase, with 6 (6/31, 19.4%) low-level copy number increase and 6 (6/31, 19.4%) high-level copy number increase. Five of six CDK4 low-level copy number increase cases were accompanied by polysomy of chromosome 12, while one case was not. Two of six CDK4 high-level copy number increase cases were accompanied by polysomy of chromosome 12, while four cases were not. CDK4 copy number increase was significantly correlated with younger patient age. In six CDK4 high-level copy number increase cases, one case was found to be accompanied by NRAS mutation, one case was accompanied by HER2 mutation, one case was accompanied by BCL2L11 mutation ​and one case was accompanied by BRAF, HER2 and BCL2L11 mutations. Our study confirmed the presence of CDK4 copy number increase in AM cases. Detecting CDK4 copy number increase by FISH can be reliable in the diagnosis of AM. Some CDK4 copy number increases are the results of polysomy of chromosome 12. CDK4 high-level copy number increase coexists with other pathogenic mutations in AM. CDK4 appears to be a promising target for AM treatment and is expected to be combined with other targeted therapies.

Exploring the prognostic and therapeutic value of HIF1A in lung adenocarcinoma

Lung adenocarcinoma (LUAD) remains a challenge within the realm of non-small cell lung cancer (NSCLC), demanding innovative diagnostic and therapeutic solutions. In this study, we systematically detected the correlation between the expression of hypoxia-induced factor 1A (HIF1A) and the clinical characteristics of LUAD, alongside lung squamous cell carcinoma (LUSC). Our bioinformatic analysis reveals that HIF1A mRNA expression is significantly upregulated in both LUAD and LUSC samples compared to non-tumorous lung tissues. The overexpression is positively correlated with increased copy number variation and negatively associated with promoter methylation. However, meta-analysis and survival analyses revealed a pronounced association between elevated HIF1A expression and poor clinical outcome specifically within the LUAD subset, with no such correlation evident in LUSC. Additionally, we explored the interplay between HIF1A expression, leukocyte infiltration, and the presence of immunosuppressive markers, revealing HIF1A's suppressive role in cytotoxicity against cancer cells. Furthermore, we performed in silico prediction to explore the correlations between HIF1A and its interacting proteins, associated pathways, glycolysis, and m6A modification, and the feasibility of targeting HIF1A with specific drugs. In summary, our study revealed the prognostic significance and therapeutic potential of HIF1A in LUAD.

Comparative Whole-Genome Sequencing Analysis of In-situ and Invasive Acral Lentiginous Melanoma: Markedly Increased Copy Number Gains of GAB2 , PAK1 , UCP2 , and CCND1 are Associated with Melanoma Invasion.

Acral lentiginous melanoma (ALM) is the most common subtype of acral melanoma. Even though recent genetic studies are reported in acral melanomas, the genetic differences between in-situ and invasive ALM remain unclear. We aimed to analyze specific genetic changes in ALM and compare genetic differences between in-situ and invasive lesions to identify genetic changes associated with the pathogenesis and progression of ALM. We performed whole genome sequencing of 71 tissue samples from 29 patients with ALM. Comparative analyses were performed, pairing in-situ ALMs with normal tissues and, furthermore, invasive ALMs with normal and in-situ tissues. Among 21 patients with in-situ ALMs, 3 patients (14.3%) had SMIM14 , SLC9B1 , FRG1 , FAM205A , ESRRA , and ESPN mutations, and copy number (CN) gains were identified in only 2 patients (9.5%). Comparing 13 invasive ALMs with in-situ tissues, CN gains were identified in GAB2 in 8 patients (61.5%), PAK1 in 6 patients (46.2%), and UCP2 and CCND1 in 5 patients (38.5%). Structural variants were frequent in in-situ and invasive ALM lesions. Both in-situ and invasive ALMs had very low frequencies of common driver mutations. Structural variants were common in both in-situ and invasive ALMs. Invasive ALMs had markedly increased CN gains, such as GAB2 , PAK1 , UCP2 , and CCND1 , compared with in-situ lesions. These results suggest that they are associated with melanoma invasion.

An increased copy number of glycine decarboxylase (GLDC) associated with psychosis reduces extracellular glycine and impairs NMDA receptor function.

Glycine is an obligatory co-agonist at excitatory NMDA receptors in the brain, especially in the dentate gyrus, which has been postulated to be crucial for the development of psychotic associations and memories with psychotic content. Drugs modulating glycine levels are in clinical development for improving cognition in schizophrenia. However, the functional relevance of the regulation of glycine metabolism by endogenous enzymes is unclear. Using a chromosome-engineered allelic series in mice, we report that a triplication of the gene encoding the glycine-catabolizing enzyme glycine decarboxylase (GLDC) - as found on a small supernumerary marker chromosome in patients with psychosis - reduces extracellular glycine levels as determined by optical fluorescence resonance energy transfer (FRET) in dentate gyrus (DG) and suppresses long-term potentiation (LTP) in mPP-DG synapses but not in CA3-CA1 synapses, reduces the activity of biochemical pathways implicated in schizophrenia and mitochondrial bioenergetics, and displays deficits in schizophrenia-like behaviors which are in part known to be dependent on the activity of the dentate gyrus, e.g., prepulse inhibition, startle habituation, latent inhibition, working memory, sociability and social preference. Our results demonstrate that Gldc negatively regulates long-term synaptic plasticity in the dentate gyrus in mice, suggesting that an increase in GLDC copy number possibly contributes to the development of psychosis in humans.

Correlation between plasma ccfDNA, mtDNA changes, CTCs, and epithelial-mesenchymal transition in breast cancer patients undergoing NACT.

Breast cancer is the most prevalent cancer in women, emphasizing need for noninvasive blood biomarkers to aid in treatment selection. Previous studies have demonstrated elevated levels of plasma circulating cell-free DNA (ccfDNA) in breast cancer patients. Both ccfDNA and mitochondrial DNA (mtDNA) are fragments released into the bloodstream. In this study, we investigated effectiveness of ccfDNA and mtDNA as indicators of treatment response and explored their potential as monitoring biomarkers. Additionally, we compared these markers with circulating tumor cell (CTC) data and assessed their relationship with epithelial-mesenchymal transition (EMT). Thirty-six female breast cancer patients and 21 healthy females were included in the study. Quantitative polymerase chain reaction (qPCR) was performed on plasma samples to measure levels of ND1, ND4, ALU115, ALU247, and GAPDH, and DNA integrity was determined by calculating ratios of ALU247/ALU115 and ND4/ND1. After treatment, patients had a significant decrease in ccfDNA levels and a significant increase in mtDNA copy number (mtDNAcn). However, there was no significant change in ccfDNA and mtDNA integrity. When comparing all groups, patients exhibited higher levels of ALU115 and ALU247 compared to controls. Moreover, patients demonstrated significantly lower ccfDNA integrity than controls. This study represents the first comprehensive investigation of plasma ccfDNA levels, mtDNAcn, and integrities collectively. Furthermore, it is the first study to explore the relationship between these markers and CTCs, cancer stem cell markers, treatment response, and metastatic status. Our findings suggest that plasma ccfDNA and mtDNA may serve as potential biomarkers for assessing chemotherapy response and can be employed alone or in combination with other biomarkers to monitor treatment efficacy in breast cancer patients.

Association between the copy number variations of Methyl-CpG binding domain family and schizophrenia

Schizophrenia is recognized as one of the most severe psychiatric disorders, with its pathogenesis likely involving genetic, epigenetic, developmental, and environmental factors. Members of the Methyl-CpG Binding Domain (MBD) Family play a crucial role in the regulation of genomic DNA methylation, and studies have implicated the association between MBD family and neurodevelopmental disorders. Copy number variations (CNVs) are a significant genetic basis for human genomic variation, also playing a critical role in the genetic processes of schizophrenia. Therefore, we aimed to evaluate the susceptibility of MBD family CNVs to schizophrenia by exploring and validating them in two separate populations using CNVplex™ and qPCR methods, and to explore the relationship between MBD family CNVs and clinical phenotypes in the overall population using chi-square tests and Fisher’s exact tests. Results suggest that an increase in MBD1 gene copy number and a deficiency in MBD2 gene copy number may be associated with the risk of schizophrenia. The deficiency in MBD2 gene copy number may increase the risk of delusion of reference and delusion of persecutory in the overall sample, as well as in males. This research provides preliminary evidence supporting the association between MBD family CNVs and schizophrenia, highlighting the potential role of the MBD family in the pathogenesis of schizophrenia.

Comprehensive Assessment of Initial Adaptation of ESBL Positive ST131 Escherichia coli to Carbapenem Exposure.

It remains unclear how high-risk Escherichia coli lineages, like sequence type (ST) 131, initially adapt to carbapenem exposure in their progression to becoming carbapenem resistant. Carbapenem mutation frequency was measured in multiple subclades of extended-spectrum β-lactamase (ESBL) positive ST131 clinical isolates using a fluctuation assay followed by whole genome sequencing (WGS) characterization. Genomic, transcriptomic, and porin analyses of ST131 C2/ H 30Rx isolate, MB1860, under prolonged, increasing carbapenem exposure was performed using two distinct experimental evolutionary platforms to measure fast vs. slow adaptation. All thirteen ESBL positive ST131 strains selected from a diverse (n=184) ST131 bacteremia cohort had detectable ertapenem (ETP) mutational frequencies with a statistically positive correlation between initial ESBL gene copy number and mutation frequency (r = 0.87, P -value <1e-5). WGS analysis of mutants showed initial response to ETP exposure resulted in significant increases in ESBL gene copy numbers or mutations in outer membrane porin (Omp) encoding genes in the absence of ESBL gene amplification with subclade specific associations. In both experimental evolutionary platforms, MB1860 responded to initial ETP exposure by increasing bla CTX-M-15 copy numbers via modular, insertion sequence 26 (IS 26 ) mediated pseudocompound transposons (PCTns). Transposase activity driven by PCTn upregulation was a conserved expression signal in both experimental evolutionary platforms. Stable mutations in Omp encoding genes were detected only after prolonged increasing carbapenem exposure consistent with clinical observations. ESBL gene amplification is a conserved response to initial carbapenem exposure, especially within the high-risk ST131 C2/ H 30Rx subclade. Targeting such amplification could assist with mitigating carbapenem resistance development.

Field test of a bioaugmentation agent for the bioremediation of chlorinated ethene contaminated sites.

Chlorinated ethenes are toxic compounds that were widely used in the past, and their improper handling and storage caused notable pollutions worldwide. In situ bioremediation by reductive dechlorination of bacteria is a cost-effective and ecologically friendly way to eliminate these pollutions. During the present study, the efficiency of a previously developed bioaugmentation agent combined with biostimulation was tested under field conditions in contaminated soil. Furthermore, the preservation of dechlorinating ability was also investigated in a long-term experiment. Initially, aerobic conditions were present in the groundwater with possible presence of anaerobic micro-niches providing habitat for Brocadia related anammox bacteria. "Candidatus Omnitrophus" was also identified as a dominant member of community then. Significant changes were detected after the biostimulation, anaerobic conditions established and most of the dominant OTUs were related to fermentative taxa (e.g. Clostridium, Trichococcus and Macillibacteroides). Dominant presence of vinyl-chloride coupled with the lack of vinyl-chloride reductase gene was observed. The most notable change after the bioaugmentation was the significant decrease in the pollutant quantities and the parallel increase in the vcrA gene copy numbers. Similar to post-biostimulation state, fermentative bacteria dominated the community. Bacterial community composition transformed considerably with time after the treatment, dominance of fermentative-mainly Firmicutes related-taxa decreased and chemolithotrophic bacteria became abundant, but the dechlorinating potential of the community remained and could be induced by the reappearance of the pollutants even after 4 years.

Characterization and integrated analysis of extrachromosomal DNA amplification in hematological malignancies

The study of extrachromosomal DNA (ecDNA), an element existing beyond classical chromosomes, contributes to creating a more comprehensive map of the cancer genome. In hematological malignancies, research on ecDNA has lacked comprehensive investigation into its frequency, structure, function, and mechanisms of formation. We re-analyzed WGS data from 208 hematological cancer samples across 11 types, focusing on ecDNA characteristics. Amplification of ecDNA was observed in 7 of these cancer types, with no instances found in normal blood cells. Patients with leukemia carrying ecDNA showed a low induction therapy remission rate (<30 %), a high relapse rate (75 %) among those who achieved complete remission, and a significantly lower survival rate compared to the general leukemia population, even those with complex chromosomal karyotypes. Among the 55 identified ecDNA amplicons, 268 genes were detected, of which 38 are known cancer-related genes exhibiting significantly increased copy numbers. By integrating RNA-Seq data, we discovered that the increased copy number, resulting in a higher amount of available DNA templates, indeed leads to the elevated expression of genes encoded on ecDNA. Additionally, through the integration of H3K4me3/H3K27ac chromatin immunoprecipitation sequencing, assay for transposase-accessible chromatin with sequencing, and high-throughput chromosome conformation capture data, we identified that ecDNA amplifications can also facilitate efficient, copy number-independent amplification of oncogenes. This process is linked to active histone modifications, improved chromatin accessibility, and enhancer hijacking, all of which are effects of ecDNA amplification. Mechanistically, chromothripsis and dysfunction of the DNA repair pathway can, to some extent, explain the origin of ecDNA.