Search Results (294)

Severe Fever with Thrombocytopenia Syndrome (SFTS) is caused by the SFTS virus (SFTSV) and is associated with a high mortality rate. Although previous studies have reported RNA modifications such as m6A on SFTSV RNA, an integrated analysis of native viral transcript architecture and multiple RNA modification types within infected cells remains lacking. Here, we used Oxford Nanopore direct RNA sequencing (DRS) to analyze native SFTSV RNA in infected cells, combining strand-specific alignment, isoform reconstruction through read endpoint clustering, isoform-level quantification, and signal-level modification identification using unmodified in vitro transcripts as a baseline. This approach allowed us to construct detailed maps of the L, M, and bidirectionally encoded S segments at single-molecule, isoform-level resolution. The results reveal a “length-layering” pattern in SFTSV transcription, anchored by recurrent 3′ termination hotspots: only a few full-length transcripts dominate expression, whereas multiple reproducible truncated isoforms were associated with discrete termination windows, a pattern less consistent with random degradation alone and suggestive of regulated transcript termination. At the single-nucleotide level, the modification landscape is predominantly Ψ (pseudouridine), followed by m⁵C (5-methylcytosine), with sparse m⁶A (N6-methyladenosine). Modification hotspots are co-located across isoforms at the same genomic coordinates, exhibiting segmental/strand asymmetry, with sharper peaks on (−) RNA. These patterns provide a testable framework and raise the possibility that transcript-boundary organization and site-constrained Ψ/m5C signals may be associated with variation in viral RNA output. More broadly, isoform proportions around termination hotspots and Ψ/m5C-enriched regions at conserved sites may serve as quantitative features for characterizing viral RNA organization and prioritizing targets for future functional investigation. Our single-molecule integrated map establishes a reproducible methodological framework for studying SFTSV RNA regulation and provides a resource for future work aimed at assessing how transcript boundaries and RNA modification patterns may relate to polymerase activity and virus–host interaction. Full article

R-loops, three-stranded nucleic acid structures formed by an RNA-DNA hybrid, have emerged as important regulators of transcription and genome stability. Although advances in high-throughput sequencing have revealed widespread R-loop landscapes, platform-specific biases hinder the identification of conserved R-loops in specific cell types. Mouse embryonic stem cells, which are transcriptionally active, provide an ideal system for investigating the potential roles of stable R-loops in RNA biology. Here, we integrated 13 independent R-loop profiling datasets from four experimental platforms to define 27,950 Common R-loop regions in mouse embryonic stem cells and characterized their chromatin environment and associated biological functions. Common R-loop regions were reproducibly detected across methods and were preferentially localized to promoter-proximal and genic regions enriched in CpG islands. Genes associated with Common R-loops were highly and stably expressed, showing strong functional enrichment in RNA metabolic processes such as mRNA processing, RNA splicing, and ribonucleoprotein complex biogenesis. Chromatin state analysis revealed that Common R-loops are enriched in transcriptionally active and regulatory contexts. Sequence feature analysis further identified GC skew as a prominent signature of Common R-loops, particularly within transcribed chromatin states. Transcription factor motif analyses have identified distinct regulatory environments in Common R-loop regions, including pluripotency-associated OCT4-SOX2-TCF-NANOG motifs in enhancers, CTCF motifs in open chromatin, and YY1 motifs in promoters. Together, this study provides the first integrated analysis of conserved R-loop regions in mouse embryonic stem cells, revealing their preferential localization at regulatory loci linked to RNA metabolism and highlighting R-loops as structural and functional nodes in RNA biology. Full article

Triplexes (TRX) are a class of flipons that can form due to the interaction of RNA with B-DNA. While many proteins have been proposed to bind triplexes, structural models of these interactions do not exist. Here, I present AlphaFold V3 (AF3) models that reveal interactions between the high-mobility group protein B1 (HMGB1), HNRNPU (SAF-A), TP53, ARGONAUTE (AGO), and REL domain proteins. The TRXs result from the sequence-specific docking of RNAs to DNA via Hoogsteen base pairing. The RNA and DNA strands in apolar TRX are oriented in the opposite 5′ to 3′ direction, while copolar TRX have RNA and DNA strands pointing in the same 5′ to 3′ direction. TRXs can incorporate different RNA classes, including long noncoding RNAs (lncRNAs), short RNAs, such as miRNAs, piRNAs, and tRNAs, nascent RNA fragments, and non-canonical base triplets. Many pathways regulated by TRX formation have evolved to constrain retroelements (EREs), which are both an existential threat to the host and a source of genotypic variation. TRXs help set the boundaries of active chromatin, repressing the expression of most EREs, while depending on other flipons to modulate cellular programs. The TRXs help nucleate folding of intrinsically disordered proteins. Full article

Fusion-associated small transmembrane (FAST) proteins are viral nonstructural proteins known to be encoded by specific members of the Spinareoviridae, specifically within the Aquareovirus and Orthoreovirus genera. These proteins specialize in mediating cell–cell fusion, leading to syncytia. Unlike enveloped viruses, naked viruses do not rely on fusion proteins for cell entry; however, such proteins may facilitate viral spread between cells. Although not essential for virus replication, FAST proteins have been shown to enhance viral replication, particularly during the early stages of infection. More recently, proteins with characteristics resembling FAST proteins have been identified in a broader range of viruses, including several rotavirus species within the family Sedoreoviridae, and, unexpectedly, in some enveloped viruses within the Coronaviridae family. Here, we present protein sequence analyses suggesting that viruses of the recently established virus family Pistolviridae (order Ghabrivirales) also encode proteins with similarity to FAST proteins. Pistolviruses are small double-stranded RNA viruses that infect piscine species, and were initially referred to as “toti-like” viruses due to genomic similarities with members of the former Totiviridae, which infect single-celled organisms. The putative FAST proteins of the pistolviruses may be expressed either from small, distinct open reading frames or suggested to be produced as cleavage products derived from polyproteins. Full article

Spray-induced gene silencing (SIGS) represents a transformative paradigm in sustainable pest management, utilizing the exogenous application of double-stranded RNA (dsRNA) to achieve sequence-specific silencing of essential genes in arthropod pests. Unlike transgenic approaches, sprayable RNA interference (RNAi) biopesticides offer superior versatility across crop systems, flexible application timing, and a more favorable regulatory and public acceptance profile. The 2023 U.S. EPA registration of Ledprona, the first sprayable dsRNA biopesticide targeting Leptinotarsa decemlineata, marks a significant milestone toward the commercialization of non-transformative RNAi technologies. Despite the milestone, large-scale field deployment faces critical bottlenecks, primarily environmental instability, enzymatic degradation by nucleases, and variable cellular uptake across pest taxa. This review critically analyzes the mechanistic basis of spray-applied RNAi and synthesizes the recent technological breakthroughs designed to overcome physiological and environmental barriers. We highlight advanced delivery strategies, including nuclease inhibitor co-application, liposome encapsulation, and nanomaterial-based formulations that enhance persistence on plant foliage and uptake efficiency. Furthermore, we discuss how innovations in microbial fermentation have drastically reduced synthesis costs, rendering industrial-scale production economically viable. Finally, we outline the roadmap for broad adoption, addressing essential factors such as biosafety assessment, environmental fate, resistance management protocols, and the path toward cost-effective manufacturing. Full article

The phenomenon of transgene silencing was first observed shortly after the generation of the initial transgenic plants. The vast body of experimental data accumulated since then constitutes an invaluable resource for dissecting the mechanisms of epigenetic gene regulation. Silencing operates at either the transcriptional (TGS) or post-transcriptional (PTGS) level and is predominantly mediated by small interfering RNAs (siRNAs). Although these two epigenetic pathways involve distinct sets of proteins and enzymes, they share fundamental mechanistic features: the generation of double-stranded RNA (dsRNA), its processing into siRNAs by DICER-LIKE (DCL) enzymes, and the assembly of an Argonaute-centered effector ribonucleoprotein complex (RISC). Guided by sequence-specific siRNAs, this complex identifies complementary target sequences with high precision. A comprehensive understanding of these regulatory pathways enables the targeted induction or suppression of specific plant genes. This review traces the history of experimental findings regarding the loss of recombinant gene activity in transformants and their progeny, which collectively established the foundation for elucidating the molecular mechanisms of transgene silencing. Full article

The study conducted a review of Listeria prevalence, virulence, and adaptations associated with leafy vegetables from small-scale farms and their journey to markets. PubMed, Taylor and Francis, Oxford, and Google Scholar databases were utilised to search for English-language journal articles published between January 1992 and 2025. Studies utilised multi-locus sequence typing (MLST), polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), multiplex PCR, pulsed-field gel electrophoresis (PFGE), and whole genome sequencing WGS, confocal scanning laser microscopy technique for the detection of Listeria species, followed by transcriptomic, phenotypic analyses, strand-specific RNA-sequencing, and membrane lipid profiling. ST₅, ST₁₂₁, and ST₃₂₁ are considered predominant and virulent and have been identified in two ready-to-eat commodities, while ST₁, ST₂, and ST₂₀₄ are considered hypervirulent strains in food processing environments. Immunocompromised groups can experience severe life-threatening infections, even death. Significant economic losses due to shutdowns for sanitary procedures can occur, impacting food security. Full article

Background: Enterococcus faecalis is an opportunistic pathogen that is capable of causing bacterial encephalitis under specific pathological conditions. MicroRNAs (miRNAs) are a class of small, single-stranded non-coding RNAs, typically approximately 21 nucleotides in length. As master regulators of gene expression, they orchestrate critical pathways across diverse organisms and a broad spectrum of diseases; however, their role during E. faecalis neuro-invasion remains unexplored. Methods: A lamb model of E. faecalis-induced encephalitis was established. Integrated analysis of high-throughput sequencing data identified oar-miR-29b as a key differentially expressed miRNA during infection. To first verify its association with inflammation, primary SBMECs were stimulated with lipoteichoic acid (LTA), confirming that oar-miR-29b expression was significantly upregulated under inflammatory conditions. Subsequently, independent gain- and loss-of-function experiments in SBMECs were performed, with inflammatory cytokine expression assessed by qPCR and tight-junction protein levels evaluated by Western blotting. Results: Functional studies demonstrated that oar-miR-29b acts as a pro-inflammatory mediator, significantly upregulating IL-1β, IL-6, and TNF-α while degrading tight-junction proteins (ZO-1, occludin, and claudin-5), thereby compromising endothelial barrier integrity. Mechanistically, bioinformatic prediction and dual-luciferase reporter assays confirmed C1QTNF6 as a direct target of oar-miR-29b. The oar-miR-29b/C1QTNF6 axis is thus defined as a novel regulatory pathway contributing to neuro-inflammation and blood-brain barrier disruption. Conclusions: Collectively, our findings identify the oar-miR-29b/C1QTNF6 axis as a novel pathogenic mechanism that exacerbates E. faecalis-induced neuroinflammation and blood-brain barrier disruption. Full article

Wheat dwarf virus (WDV) is a major constraint to global wheat production, causing severe yield losses and economic disruption. Understanding the molecular basis of wheat–WDV interactions is essential for developing resistant cultivars. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of gene expression and defence. This study identified ncRNAs involved in wheat responses to WDV, including host lncRNAs, miRNAs, and viral small interfering RNAs (siRNAs) targeting WDV genomic regions. High-throughput sequencing revealed extensive ncRNA reprogramming under WDV infection. A total of 437 differentially expressed lncRNAs (DElncRNAs) and 58 miRNAs (DEmiRNAs) were detected. Resistant genotypes displayed more DElncRNAs (204 in Svitava; 163 in Fengyou 3) than the susceptible Akteur (141). In Akteur, 66.7% of DElncRNAs were downregulated, whereas in Svitava, 56.9% were upregulated. Akteur also exhibited more DEmiRNAs (28) than resistant genotypes (15), with predominant downregulation. A co-expression network analysis revealed 391 significant DElncRNA–mRNA interactions mediated by 16 miRNAs. The lncRNA XLOC_058282 was linked to 298 transcripts in resistant genotypes, suggesting a central role in the host defence. Functional annotation showed enrichment in signalling, metabolic, and defence-related pathways. Small RNA profiling identified 1166 differentially expressed sRNAs targeting WDV, including conserved hotspots and 408 genotype-specific sites in Akteur versus Fengyou 3. Infected plants displayed longer sRNAs, a sense-strand bias, and a 5′ uridine preference, but lacked typical 21–24 nt phasing. These findings highlight the central roles of ncRNAs in orchestrating wheat antiviral defence and provide a molecular framework for breeding virus-resistant wheat. Full article

The role of alternative nucleic acid structures (ANS) in biology is an area of increasing interest. These non-canonical structures include the Z-DNA and Z-RNA duplexes (ZNA), the three-stranded triplex, the four-stranded G-quadruplex (GQ), and i-motifs. Previously, the biological relevance of ANS was dismissed. Their formation in vitro often required non-physiological conditions, and there was no genetic evidence for their function. Further, structural studies confirmed that sequence-specific transcription factors (TFs) bound B-DNA. In contrast, ANS are formed dynamically by a subset of repeat sequences, called flipons. The flip requires energy, but not strand cleavage. Flipons are enriched in promoters where they modulate transcription. Here, computational modeling based on AlphaFold V3 (AF3), under optimized conditions, reveals that known B-DNA-binding TFs also dock to ANS, such as ZNA and GQ. The binding of HLH and bZIP homodimers to Z-DNA is promoted by methylarginine modifications. Heterodimers only bind preformed Z-DNA. The interactions of TFs with ANS likely enhance genome scanning to identify cognate B-DNA-binding sites in active genes. Docking of TF homodimers to Z-DNA potentially facilitates the assembly of heterodimers that dissociate and are stabilized by binding to a cognate B-DNA motif. The process enables rapid discovery of the optimal heterodimer combinations required to regulate a nearby promoter. Full article

Butidae is a family of teleost fishes with diverse morphological and ecological adaptations, including the marbled goby (Oxyeleotris marmorata), a large species of high economic value in Southeast and East Asia. The previous mitogenomic studies on cultured populations of O. marmorata from non-native habitats have provided limited insights into genetic divergence, structural variation, and evolutionary relationships. Hence, this study presented the complete mitochondrial genome of O. marmorata from its native habitat in Indonesia, providing structural characterization, assessment of genetic diversity, and matrilineal phylogenetic analysis. The circular mitogenome was 16,525 bp, comprising 37 genes and a non-coding control region (CR). The gene organization and strand distribution were conserved among Oxyeleotris species, with 28 genes on the heavy strand and nine on the light strand, and a pronounced A+T compositional bias. The comparative analyses of O. marmorata (from both native and cultured habitats) and Oxyeleotris lineolata mitogenomes revealed minor variations in intergenic spacers, gene overlaps, protein-coding gene (PCGs) lengths, and codon usage patterns. Conversely, the nonsynonymous and synonymous substitution ratios observed in species of the family Butidae and its closest related family (Eleotridae) indicate strong purifying selection in the present dataset. Notably, the ATG was the predominant start codon, whereas the COI gene utilized GTG, and amino acid composition analysis demonstrated high frequencies of arginine, leucine, and serine. Most transfer RNAs retained the canonical cloverleaf secondary structure except for trnS1, which lacked a functional dihydrouridine arm, whereas the CR contained four conserved sequence blocks with variable nucleotide motifs and no detectable tandem repeats. The haplotype analysis of native (Indonesia) and introduced populations (China) highlighted three haplotypes with high diversity (Hd = 1.0000) and substantial nucleotide variation (π = 0.6667). The genetic divergence across 13 PCGs was gene-specific, with COI and ND5 showing the highest variation, while ND4L and ATP8 were highly conserved. The phylogenetic analyses based on concatenated 13 PCGs using both Bayesian Inference and Maximum Likelihood methods revealed that Oxyeleotris forms a monophyletic clade and is closely related to Bostrychus sinensis. In addition, the broader phylogenetic framework inferred the matrilineal relationships within the family Butidae and its closest related family, Eleotridae. This study also recommends expanding analyses to include the mitogenomes of the remaining 17 Oxyeleotris species, together with comprehensive genomic data, to further elucidate their genetic architecture, evolutionary history, and ecological adaptability across diverse aquatic ecosystems. Full article

Rotavirus alphagastroenteritidis (rotavirus) infects a broad range of hosts, including humans and various animal species. Its genome comprises 11 segments of double-stranded RNA, making it highly prone to genetic diversity through gene reassortment. Although rotavirus strains are typically host-specific, novel human strains with global impact often originate from interspecies transmission of animal rotaviruses. This review explores the critical role of interspecies transmission coupled with genetic reassortment in rotavirus adaptation to humans, contextualizing key studies and methodological advances. Central to this progress was the development of tools to analyse entire genomes and distinguish homologous from heterologous strains. We trace the evolution from RNA-RNA hybridisation to whole-genome sequencing, which underpins genotype constellation and sub-genotype phylogeny. A decade-long surveillance of the bovine-like G8 rotavirus in Vietnam offers a compelling model: for an animal rotavirus to become a successful human pathogen, it must replace its animal-derived genes with human-derived counterparts through reassortment. Retaining the animal-origin G8 VP7 gene is enabled by acquiring a compatible human VP4 gene (specifically P[8]) and DS-1-like backbone genes. Building on this model of reassortment-driven adaptation, our investigation into the unusual G1P[6] strain AU19, of wholly porcine origin, supports the hypothesis that the predominant human G1 rotavirus also evolved from a successful interspecies transmission event. Phylogenetic analysis suggests the ancestral human G1 gene emerged from a porcine rotavirus between 1915 and 1948, later reassorting with human strains to acquire Wa-like backbone genes, ultimately becoming a stable and dominant part of the human rotavirus population. In conclusion, genetic reassortment is a key mechanism transforming sporadic zoonotic events into sustained human-pathogens, although other factors remain to be fully defined. We conclude by highlighting key areas for further research. Full article

Epigenetics encompasses heritable but reversible modifications of gene expression that occur without changes in the DNA sequence and involve mechanisms such as DNA and RNA methylation and histone modifications. These mechanisms modulate chromatin architecture, genome stability, and cellular responses to environmental stressors, and their dysregulation contributes to oncogenesis and cancer progression. In parallel, radiotherapy remains a cornerstone of cancer treatment; furthermore, ionizing radiation induces epigenetic modifications alongside direct DNA double-strand breaks and oxidative damage. Radiation-induced epigenetic changes, including global or locus-specific DNA methylation shifts (e.g., genes promoter CpG islets), histone acetylation and methylation imbalances, are increasingly recognized as key contributors to molecular radioresistance. These adaptive responses may enhance tumor cell survival, affect therapeutic efficacy, and promote metastasis. Understanding the interplay between radiation exposure and epigenetic remodeling opens new perspectives for precision oncology and diagnostics. Epigenetic biomarkers hold potential for predicting treatment response and prognosis, while epigenetic modifiers may sensitize tumors to radiation. This review summarizes current evidence on radiation-induced epigenetic mechanisms and evaluates their diagnostic, prognostic, and therapeutic implications in cancer management. Full article

Long non-coding RNAs (lncRNAs) are crucial regulators in eukaryotic organisms, yet their roles in filamentous fungi, particularly in environmental adaptation and metabolic changes, remain largely unexplored. Here, we investigated the roles of lncRNAs in salt stress response, morphological differentiation, and metabolic regulation in Eurotium cristatum. Using strand-specific RNA sequencing, we identified lncRNAs in sexual and asexual mycelia of E. cristatum and analyzed their expression profiles. We identified 203 lncRNAs, with 120 significantly differentially expressed (FDR < 0.01; |log₂ (fold change)| ≥ 1) under salt stress, including 57 upregulated and 63 downregulated in the asexual morph compared to the sexual morph. These lncRNAs correlated with physiological indicators like mycelial biomass, polysaccharide content, and melanin production. Target gene prediction and functional enrichment analysis revealed that these lncRNAs influenced morphogenesis and secondary metabolite synthesis in E. cristatum by regulating pathways including carbohydrate metabolism, peroxisome function, and protein ubiquitination. The lncRNA MSTRG.10627.3 showed the highest upregulation (log₂FC = 10.53, FDR < 1 × 10⁻¹⁰⁵), while MSTRG.3124.1 was significantly downregulated in the sexual morph (log₂FC = −4.94, FDR < 1 × 10⁻⁸⁸). A regulatory network of lncRNAs involved in salt stress responses was constructed, providing insights into fungal environmental adaptation mechanisms and potential targets for industrial strain improvement. Full article

Toll-like receptor 9 (TLR9) and Toll-like receptor 3 (TLR3), which are widely expressed in dendritic cells (DCs), function as key pattern recognition receptors (PRRs) in the immune system. Their primary roles involve specifically detecting pathogen-associated molecular patterns (PAMPs): TLR9 recognizes unmethylated CpG motifs predominantly found in bacterial and viral DNA, while TLR3 identifies viral double-stranded RNA (dsRNA), a molecular signature associated with viral replication. Their specific agonists [CpG ODN (a TLR9 agonist) and poly(I:C) (a TLR3 agonist)] can effectively activate DCs and enhance the expression of immune activation-related molecules. In this study, by establishing a mouse primary dendritic cell model and a glioma-bearing mouse model, and employing techniques such as transcriptome sequencing, we found that combined stimulation with CpG ODN and poly(I:C) significantly enhanced the anti-tumor function of DCs: in vitro, DCs subjected to combined stimulation showed upregulation of anti-tumor-related surface markers, enhanced migratory capacity, and a more effective activation of CD8⁺ T cells; in vivo, a DC vaccine loaded with tumor lysate antigen and stimulated with this combined regimen significantly delayed the progression of glioma in tumor-bearing mice. Further investigation revealed that the underlying mechanism for this enhanced effect may involve TLR9 activation promoting TLR3 upregulation through the p38 MAPK-ATF3 signaling axis. Consequently, we designed a sequential stimulation protocol (first CpG ODN then poly(I:C)), which demonstrated a stronger anti-glioma effect compared to simple combined stimulation. This study provides a new strategy for enhancing the immune efficacy of DC vaccines and has potential significance for promoting the clinical translation of DC vaccines. Full article