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ColE1 plasmid incompatibility: localization and analysis of mutations affecting incompatibility.

Deletion mutants of plasmid ColE1 that involve the replication origin and adjacent regions of the plasmid have been studied to determine the mechanism by which those mutations affect the expression of plasmid incompatibility. It was observed that (i) a region of ColE1 that is involved in the expression of plasmid incompatibility lies between base pairs -185 and -684; (ii) the integrity of at least part of the region of ColE1 DNA between base pairs -185 and -572 is essential for the expression of ColE1 incompatibility; (iii) the expression of incompatibility is independent of the ability of the ColE1 genome to replicate autonomously; (iv) plasmid incompatibility is affected by plasmid copy number; and (v) ColE1 plasmid-mediated DNA replication of the lambda phage-ColE1 chimera lambda imm434 Oam29 Pam3 ColE1 is inhibited by ColE1-incompatible but not by ColE1-compatible plasmids.

Colicins

[Analysis of mutations induced by alkylating compounds in Drosophila sperm. I. Character of visible changes induced by N-nitrosoethylurea and ethylmethanesulfonate in a succession of Drosophila generations].

Newly appearing hereditary traits were observed in several generations of Drosophila melanogaster: changes in eye and body colour, wing shape, number and shape of chaetae. The results obtained may be interpreted as the evidence for the realization of potential changes induced by NEU and EMS into visible mutations during 1-4th generations. X-irradiation (at a dose of 1000 r) of males from the first generation did not affect the realization of long-living potential changes induced by NEU.

Animals

[Analysis of mutation frequency following continuous and fractionated application of ethyleneimine and ethyl methanesulfonate to male sex cells of Drosophila melanogaster].

The increase in the frequency of recessive lethal sex-linked mutations induced by fractionated effect of ethylene imine (EI) an ethylmethanesulphonate (EMS) on mature sperm of Drosophila melanogaster was observed and compared uith prolonged treatment (8h) and with the additive effect. This effect of dose fractionation was observed in the case of the treatment of sperms in male gonads and in female spermathecas. The increase of the mutation frequency was noted by brood-pattern method after fractionated treatment of spermatocytes and spermatogonia only with EMS. This increase was not observed under the effect of EI on spermatocytes and spermatogonia because of the high sierilization activity of EI. Possible mechanisms of the effects observed are discussed.

Animals

Global Evolution and Transmission Dynamics of Enterovirus D68.

Enterovirus D68 (EV-D68), a serotype of the enterovirus species D, has garnered significant attention due to outbreaks reported in 2014, 2016, and 2018. In this study, 36 Chinese EV-D68 strains were isolated, sequenced, and combined with all EV-D68 VP1 sequences from GenBank to form a data set of 1679 sequences. This data set served as the basis for phylogenetic, evolutionary dynamics, phylogeographic, and key amino acid site mutation analyses of EV-D68. Based on the VP1 region, EV-D68 is classified into four genotypes (A-D), and seven subgenotypes (B1-B3, D1-D4), with B3 and D3 being the predominant subgenotypes. Bayesian skyline plots indicated that genotypes B and D experienced multiple population expansions, aligning with reported EV-D68 outbreaks. Phylogeographic analyses of the B3 subgenotypes revealed sequences from Europe and North America clustering into a single evolutionary branch, suggesting significant transmission between these regions. Additionally, mutation analysis identified VP1-98 as a high-frequency mutation site, differing significantly between the previously prevalent A and C genotypes and the currently prevalent B and D genotypes. However, the functional implications of this mutation require further investigation. This study provides a solid theoretical basis for epidemiological research, disease surveillance, and prevention efforts related to EV-D68.

Enterovirus Infections

Genomic adaptation in group B Streptococcus following intrapartum antibiotic prophylaxis and childbirth.

Through vaginal colonization, GBS causes severe outcomes including neonatal sepsis and meningitis. Although intrapartum antibiotic prophylaxis (IAP) has reduced neonatal disease rates, persistent GBS colonization has been observed in patients following prophylaxis. To determine whether IAP selects for genomic signatures that enhance GBS survival and persistence, a pangenome analysis was performed on 97 isolates from 58 participants before (prenatal) and after (postpartum) IAP/childbirth. Thirty-one of the 34 paired strains from participants with persistent colonization clustered together in the core gene phylogeny, suggesting that the strains recovered at the postpartum sampling were highly similar to those recovered at the prenatal visit. A core-gene mutation analysis identified mutations in 74% (n=23) of the 31 postpartum genomes when compared to the prenatal strains of the same multilocus sequence type recovered from the same individuals. Several strains had acquired mutations in the same colonization-associated genes, though two postpartum strains accounted for most of the mutations. These two outliers were classified as mutators based on high mutation rates and mutations within DNA repair system genes. Increased biofilm production was observed in half of the postpartum strains relative to the prenatal strains, which is supported by the presence of point mutations in genes associated with adherence. Together, these findings suggest that antibiotics may impose a selective pressure on GBS that selects for mutations and phenotypes that promote adaptation and survival in vivo. Enhanced survival in the genitourinary tract can lead to persistent colonization, increasing the likelihood of invasive disease in subsequent pregnancies and in newborns following IAP.

Journal Article

Somatic mutations reveal hyperactive Notch signaling in prurigo nodularis.

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by pruritic skin nodules of unknown etiology. Little is known about genetic changes in PN pathogenesis, particularly somatic events, which are often implicated in inflammatory conditions. We thus performed whole-exome sequencing on 54 lesional and nonlesional skin biopsies from 17 patients with PN and 10 patients with atopic dermatitis (AD) for comparison. Somatic mutational analysis revealed that PN lesional skin harbors recurrent somatic mutations in fibrotic, neurotropic, and cancer-associated genes that are absent in adjacent PN nonlesional skin. Nonsynonymous mutations were most frequently present in NOTCH1 and the Notch signaling pathway, a key regulator of cellular proliferation and tissue fibrosis. In contrast, NOTCH1 mutations were absent in AD. Somatic copy-number analysis, combined with expression data, identified recurrently deleted and downregulated genes in PN lesional skin, which are associated with axonal guidance and extension. Follow-up immunofluorescence validation demonstrated increased NOTCH1 expression in PN lesional skin fibroblasts and increased Notch signaling in PN lesional dermis. Finally, a multicenter analysis revealed increased risk of NOTCH1-associated diseases in patients with PN. In characterizing the somatic landscape of PN, this study highlights the potential role of Notch pathway dysregulation in PN pathogenesis and fibrosis.

Humans

Genomic Analysis of Circulating Tumor Cells at the Single-Cell Level.

Circulating tumor cells (CTCs) have a great potential for noninvasive diagnosis and real-time monitoring of cancer. A comprehensive evaluation of four whole genome amplification (WGA)/next-generation sequencing workflows for genomic analysis of single CTCs, including PCR-based (GenomePlex and Ampli1), multiple displacement amplification (Repli-g), and hybrid PCR- and multiple displacement amplification-based [multiple annealing and loop-based amplification cycling (MALBAC)] is reported herein. To demonstrate clinical utilities, copy number variations (CNVs) in single CTCs isolated from four patients with squamous non-small-cell lung cancer were profiled. Results indicate that MALBAC and Repli-g WGA have significantly broader genomic coverage compared with GenomePlex and Ampli1. Furthermore, MALBAC coupled with low-pass whole genome sequencing has better coverage breadth, uniformity, and reproducibility and is superior to Repli-g for genome-wide CNV profiling and detecting focal oncogenic amplifications. For mutation analysis, none of the WGA methods were found to achieve sufficient sensitivity and specificity by whole exome sequencing. Finally, profiling of single CTCs from patients with non-small-cell lung cancer revealed potentially clinically relevant CNVs. In conclusion, MALBAC WGA coupled with low-pass whole genome sequencing is a robust workflow for genome-wide CNV profiling at single-cell level and has great potential to be applied in clinical investigations. Nevertheless, data suggest that none of the evaluated single-cell sequencing workflows can reach sufficient sensitivity or specificity for mutation detection required for clinical applications.

Carcinoma, Non-Small-Cell Lung

Clinical and genomic characterization of Influenza A co-infection with SARS-CoV-2 and Influenza B: a respiratory surveillance study in Assam, India.

Influenza and SARS-CoV-2 are the primary contributors to seasonal respiratory infections and frequently co-circulate, creating significant health challenges. The present respiratory surveillance study was conducted in Dibrugarh, Assam, India from January 2025 to August 2025 to investigate the genomic characteristics of circulating viruses and identify potential co-infections. Overall, 4,948 respiratory samples were screened using multiplex real-time PCR, followed by subtyping of Influenza A and Influenza B. Next-generation sequencing (NGS) was performed in selected positives of SARS-CoV-2 and Influenza A. Genomic analysis included mutational profiling, phylogenetic analysis and N-glycosylation site prediction using bioinformatics tools. Two co-infection cases were detected: one involving Influenza A (H3N2) with SARS-CoV-2 (Omicron XFG lineage) and another involving Influenza A (H3N2) with Influenza B (Victoria lineage). Both patients experienced mild illness without hospitalisation. NGS revealed that the Influenza A (H3N2) viruses belonged to clade 3C.2a1b.2a.2a.3a.1 while SARS-CoV-2 sequence was classified under the Omicron XFG lineage. Mutational analysis of the HA gene showed several amino acid differences compared to the reference vaccine strain A/Darwin/6/2021. N-glycosylation analysis predicted conserved sites at positions 79, 181, 262, and 301 in all strains along with an additional predicted site at position 110 in both co-infection cases. Although the co-infection cases presented with mild clinical manifestations, the observed genomic variations indicate a potential role of co-infecting viruses in shaping viral evolution. Given the limited genomic data available from Northeast India, the study underscores the need for sustained large scale follow up and genomic surveillance to monitor emerging mutations and target future vaccine strategies.

Humans

Genetic heterogeneity and pathogenic potential of historical Crimean-Congo hemorrhagic fever virus isolates in China.

The Crimean-Congo hemorrhagic fever virus (CCHFV) poses a significant public health threat. In China, CCHFV has been circulating for decades, yet the genomic diversity and pathogenic potential of the circulating strains remain poorly characterized, hindering risk assessment and countermeasure development. In this study, we recovered 24 historical CCHFV strains isolated between 1966 and 2004 from humans, ticks and jerboas in Xinjiang Uyghur Autonomous Region of China. Whole-genome sequencing was performed, followed by comprehensive analyses of their phylogenetic relationships, in vitro infectivity and in vivo pathogenicity. Phylogenetic analyses revealed high genetic heterogeneity, identifying seven genotypes for the L segment, nine for the M segment (including a novel Asia 4 genotype), and nine for the S segment. Amino acid mutation analysis revealed that the mucin-like domain (MLD) of the glycoprotein (GP) exhibited the highest mutation rate, contributing substantially to sequence diversity. In vitro, Asia 2 (75024) and Asia 3 (79121M18) strains exhibited robust replication in monkey-, hamster-, and human-derived cell lines. In C57BL/6 mice, all four representative strains induced viral replication and specific antibody responses (IgM and IgG), causing mild to moderate pathological damage in the liver, spleen, and kidneys. In IFNAR-/- mice, virulence varied markedly among representative strains: Asia 2 and Asia 3 strains were highly lethal (LD50 < 1 TCID50), Asia 1 was moderately virulent (LD50 = 142.5 TCID50), and Asia 4 exhibited atypical, non-dose-dependent mortality. Collectively, our work reports a novel Asia 4 genotype and suggests strain- and lineage-associated differences in virulence for CCHFV in China, providing critical insights for surveillance and targeted countermeasure development.

Animals

Comparative Genomic Analysis of Six Mycoplasma Gallisepticum Strains: Insights into Genetic Diversity and Antibiotic Resistance.

Mycoplasma gallisepticum (MG) is a significant pathogen that causes respiratory diseases, which have had a substantial economic impact on the poultry industry. Despite the resistance of MG to antibiotics, it is imperative to identify genetic diversity in order to develop countermeasures. In this study, the genomes of six MG strains were examined to gain deeper insights into the mutations. The data pertaining to Variant Annotation and Mutation Analysis using SnpEff, along with the calculation of mutation rates as the ratio of total mutations to the length of the genomic regions analyzed, were thoroughly examined. The comprehensive evaluation yielded a total of 25,942 variants across the six strains, underscoring substantial genetic diversity. Notably, strain S6 exhibited a preponderance of frameshift mutations. A notable finding was the presence of a mutation in the MsbA gene shared by all six strains. Furthermore, five of the six strains, with the exception of strain F99 Lab, exhibited a mutation at position 5158, which impacts a multidrug transport system. Notably, strain ATCC exhibits a distinctive mutation at position 942, while strain S6 displays a unique mutation at position 6855, which is linked to efflux ABC transporter components. Furthermore, a substantial degree of genetic variation was observed among the CrmA, GapA, and vlhA genes among the various strains. High-impact changes, such as insertions and deletions, exhibited a higher frequency in CrmA, particularly in strain S6. Conversely, nonsynonymous variations demonstrated a heightened prevalence in GapA, particularly in strain F99 Lab. The vlhA gene exhibited a spectrum of effects, ranging from synonymous mutations to high-impact mutations such as stop-gains and frameshifts, particularly in strains k5111a and k4602. The functional variations observed among the strains can be attributed to these mutations, which have the potential to alter gene expression or protein function. Furthermore, substantial mutations in the dxr and rpoC genes were associated with antibiotic resistance. These mutations underscore the ongoing evolutionary adaptations of M. gallisepticum. Consequently, there is an imperative for the revision of treatment protocols and the formulation of targeted vaccines to regulate resistance within the poultry industry.

Mycoplasma gallisepticum

Age-related genomic characterization and therapeutic targets in Chinese breast cancer: insights from prospective targeted sequencing and clinical data analysis.

BACKGROUND: In China, breast cancer occurs at a much younger age and has a higher recurrence and mortality rate. However, with changes in lifestyle, there has been a trend towards an older age of breast cancer incidence in Chinese women. There is a paucity of large-scale next-generation sequencing cohorts for the analysis of genomic characterization in these populations and the identification of potential therapeutic targets. METHODS: To address this gap, we performed prospective targeted sequencing of tumor and blood samples from Chinese patients and collected detailed clinical information. We then categorized patients into two groups based on age (<&#x2009;40&#xa0;years, n&#x2009;=&#x2009;637;&#x2009;&#x2265;&#x2009;40&#xa0;years, n&#x2009;=&#x2009;3442) and proceeded to provide comprehensive descriptions of somatic and germline mutations in both groups. RESULTS: The somatic mutation analysis revealed that PIK3CA, FOXA1, and TBX3 mutations were more prevalent in elderly patients. By leveraging the aforementioned mutational characteristics, we employed our institution's FUTURE-SUPER clinical trial, an umbrella study targeting metastatic breast cancer, to confirm the potential benefits of PI3K-AKT-mTOR pathway inhibitors among elderly patients with breast cancer. Furthermore, TP53 and ERBB2 were more likely to be co-mutated in young women. Patients with TP53 and ERBB2 co-mutation tend to have a poorer prognosis, but through investigation of the SPARK cohort, patients carrying the TP53 and ERBB2 co-mutation are more likely to benefit from immune checkpoint inhibitor combination with tyrosine kinase inhibitor therapy. In our study, we observed a higher frequency of mutations in the DNA homology-dependent recombination pathway in young patients with breast cancer, which was associated with an elevated Ki67 index. Additionally, we confirmed a significant prevalence of germline breast cancer susceptibility gene 1 (gBRCA1) mutations in young patients, whereas germline checkpoint kinase 2 (gCHEK2) mutations are more common in elderly patients. CONCLUSIONS: Our study, which makes use of the largest Chinese breast cancer sequencing cohort, sought to characterize the age-related genomic profile of breast cancer patients and identify novel therapeutic opportunities for individuals with breast cancer.

Adult

Genetic and functional analyses of CTBP2 in anorexia nervosa and body weight regulation.

The C-terminal binding protein 2 (CTBP2) gene (translational isoforms: CTBP2-L/S, RIBEYE) had been identified by a cross-trait analysis of genome-wide association studies for anorexia nervosa (AN) and body mass index (BMI). Here, we did a mutation analysis in CTBP2 by performing polymerase chain reactions with subsequent Sanger-sequencing to identify variants relevant for AN and body weight regulation and ensued functional studies. Analysis of the coding regions of CTBP2 in 462 female patients with AN&#xa0;(acute or recovered), 490 children and adolescents with severe obesity, 445 healthy-lean adult individuals and 168 healthy adult individuals with normal body weight detected 24 variants located in the specific exon of RIBEYE.&#xa0;In the initial analysis, three of these were rare non-synonymous variants (NSVs) detected heterozygously in patients with AN (p.Arg72Trp - rs146900874; p.Val289Met -rs375685611 and p.Gly362Arg - rs202010294). Four NSVs and one heterozygous&#xa0;frameshift variant were exclusively detected in children and adolescents with severe obesity (p.Pro53Ser - rs150867595; p.Gln175ArgfsTer45 - rs141864737; p.Leu310Val - rs769811964; p.Pro397Ala - rs76134089 and p.Pro402Ser - rs113477585). Ribeye mRNA was detected in mouse hypothalamus. No effect of fasting or overfeeding on murine hypothalamic Ribeye expression was determined. Yet, increased Ribeye expression was detected in hypothalami of leptin-treated Lepob/ob mice. This increase was not related to reduced food intake and leptin-induced weight loss. We detected rare and frequent variants in the RIBEYE specific exon in both patients with AN and in children and adolescents with severe obesity. Our data suggest RIBEYE as a relevant gene for weight regulation.

Humans

Genomic profiling of aggressive pathologic features in lung adenocarcinoma.

INTRODUCTION: Pathologic features involving LVI (lympho-vascular invasion), PNI (perineural invasion), STAS (spread through air spaces), and Grade 3 pattern (from the International Association for the Study of Lung Cancer grading system) are related to having an aggressive phenotype and linked to poor prognosis. However, few studies have conducted in-depth analyses of these features simultaneously with genomic profiling. METHODS: A total of 1559 sequencing of adenocarcinoma samples were included in the common driver mutations analysis, 1306 samples were brought into genomic mapping analysis. OncoSG's East Asian ancestry dataset was implemented for Tumor-Node-Metastasis-Biomarker (TNMB) classification and prognostic assessment. RESULTS: EGFR was more significantly prevalent in LVI negativity (P&#xa0;=&#xa0;0.021), STAS negativity (P&#xa0;=&#xa0;0.002), and moderate grade (P&#xa0;<&#xa0;0.001). ALK was significantly interrelated with LVI (P&#xa0;=&#xa0;0.028), STAS (P&#xa0;<&#xa0;0.001), and poor grade (P&#xa0;<&#xa0;0.001); ROS1 and STAS positivity (P&#xa0;=&#xa0;0.031), poor grade (P&#xa0;=&#xa0;0.016) were significantly related. KRAS (P&#xa0;=&#xa0;0.003) and BRAF-V600E (P&#xa0;=&#xa0;0.002) were only significantly intertwined with poor grade. Apart from common driver mutations, TP53, CHEK2, KEAP1, PTEN, RB1, NF1 were significantly enriched in LVI samples (P&#xa0;<&#xa0;0.05). TP53, PTEN, CTNNB1, HGF, NF1 were more prominent in STAS (P&#xa0;<&#xa0;0.01). TP53, LRP1B, NF1 were significantly more prevalent in Grade 3 pattern (P&#xa0;<&#xa0;0.001). The mixture of STK11, PTEN, and TOP2A generated by exclusive mutations may be a potential predictor of TNMB categorization towards survival. The HR of stage II compared I of TNMB was 2.28 (95&#xa0;% CI 1.36-3.86, P&#xa0;<&#xa0;0.001), while stage III compared II was 1.95 (95&#xa0;% CI 1.04-3.21, P&#xa0;=&#xa0;0.031). CONCLUSIONS: This analysis demonstrated the correlation of pathologic features with common driver mutations, key mutations and canonical oncogenic signaling pathways. The data highlighted the similarities and differences among these features horizontally, and provide new insights in TNMB classification and prognostic assessment.

Humans

Identification of Specific Virulence Factors of Pseudomonas Strains in the Biocontrol of the Potato Pest Tecia solanivora.

Tecia solanivora (The Guatemalan potato tuber moth) is a major potato pest, responsible for up to 20% of crop losses and a significant economic impact. Certain Pseudomonas exhibit insecticidal activity and produce virulence factors with cytotoxic and antimicrobial properties, positioning them as promising candidates for biological control. This study evaluated seven Pseudomonas strains with insecticidal activity and identified key virulence factors involved. The strains demonstrated varying degrees of insecticidal activity, with Pseudomonas protegens strains CHA0 and 59C being the most lethal, causing over 75% mortality and triggering a systemic melanization response in the insects. Genomic analysis revealed 175 virulence-related genes shared across all strains and 16 genes specific to the highly insecticidal ones, including genes for antimicrobial compounds and insect toxins. Mutational analysis confirmed the roles of hydrogen cyanide, 2,4-diacetylphloroglucinol, pyoluteorin, Fit toxin, and two-partner secretion systems in P. protegens CHA0 insecticidal activity. This strain also exhibited insecticidal effects on adult T. solanivora and delayed egg hatching and pupal emergence. In microcosm assays, P. protegens CHA0 reduced tuber damage caused by T. solanivora larvae by up to 38%. These results suggest that P. protegens CHA0 is a promising biocontrol agent, providing a sustainable alternative to chemical pesticides to control T. solanivora.

Animals

Genomic Analysis and Clinical Correlation of Non-Small Cell Lung Cancer with Special Reference to Brain Metastasis.

BACKGROUND: Next-generation sequencing (NGS) has improved genomic analysis depth in precision oncology. This study analyzed genomic biomarker testing in stage IV NSCLC, focusing on brain metastasis and clinicopathological correlations. OBJECTIVE: To study molecular markers and clinicopathological correlations in stage IV NSCLC patients, with and without brain metastasis. METHODS: A total of 169 stage IV NSCLC patients were studied from April 2023 to May 2025. Demographic data, clinical presentations, and mutation analyses were assessed using NGS on tissue blocks or liquid biopsies. RESULTS: Among 169 patients, 41.42% (n = 70) had brain metastasis (NSCLC-BM), while 58.58% (n = 99) had no brain metastasis (mNSCLC). Median ages were 51.5 and 56 years, respectively. Adenocarcinoma comprised 95.27% (n = 161) of cases. The cerebral hemisphere was the most common intracranial metastatic site, while skeletal involvement was the most common extracranial site. Headache was the predominant neurological symptom. EGFR mutations were the most common overall. EGFR > TP53 > ALK > other mutations were observed in NSCLC-BM, while EGFR > TP53 > KRAS > other mutations were seen in mNSCLC. Mutation analysis stratified by smoking history (&#x3c7;&#xb2;(1) = 1.347, p = 0.245) and sex (&#x3c7;&#xb2;(1) = 0.0302, p = 0.862) was not statistically significant. The benefit of gefitinib plus chemotherapy in EGFR exon 19 and exon 21 L858R mutations was greater in mNSCLC (log-rank &#x3c7;&#xb2;(1) = 10.813, p = 0.001) than in NSCLC-BM (log-rank &#x3c7;&#xb2;(1) = 3.100, p = 0.078). Median survival was 11 months (95% CI: 7.506-14.494) for NSCLC-BM versus 21 months (95% CI: 8.365-33.635) for mNSCLC, with a statistically significant difference (log-rank &#x3c7;&#xb2;(1) = 8.639, p = 0.003). CONCLUSION: NSCLC-BM showed higher genomic biomarker enrichment (80% vs. 68.68%) but poorer outcomes than mNSCLC. EGFR was the most common targetable mutation, followed by ALK in NSCLC-BM and KRAS in mNSCLC.

Humans