Search Results (200)

In this study, we investigated the long-term evolutionary dynamics of human norovirus GII.17[P17] using the RNA-dependent RNA polymerase (RdRp) region and the VP1 capsid gene, integrating phylogenetics, time-scaled inference, phylodynamics, and structure-based analyses. Maximum-likelihood phylogenies of both genomic regions consistently resolved four major clades (Clades 1–4). VP1 patristic-distance distributions indicated higher within-clade diversity in the phylogenetically basal Clades 1 and 3, whereas Clades 2 and 4 showed lower diversity, consistent with recent demographic expansion. Similarity-plot analysis identified pronounced variability in the VP1 P2 domain, while the S and P1 domains remained comparatively conserved, supporting P2 as the primary hotspot of diversification. Bayesian time-scaled analyses estimated the most recent common ancestor around 1993 (VP1) and 2000 (RdRp) and revealed two major lineages (Clade 1/2 and Clade 3/4), with the split between Clades 3 and 4 occurring around 2016–2017. Bayesian skyline plots showed a marked increase in effective population size after 2013, and substitution-rate estimates indicated faster evolution in VP1 than in RdRp, with higher VP1 rates in the Clade 3/4 lineage than in Clade 1/2. Capsid dimer modeling further mapped high-confidence conformational B-cell epitopes and positively selected residues predominantly to the distal surface of P2, with broadly conserved spatial patterns across clades. Compared with the Clade 1 reference (Kawasaki323), Clade 2 accumulated numerous P2 substitutions, whereas Clades 3 and 4 retained fewer changes and remained closer to Clade 1 at the amino-acid level. Together, these results suggest lineage turnover within GII.17[P17] driven by constrained diversification at the P2 surface, potentially contributing to the recent predominance of the Clade 3/4 lineage. Full article

Myogenic mechanobiology governs how mechanical cues regulate myocyte organization, alignment, and functional maturation; however, in vitro platforms that enable quantitative control and real-time readout of myogenic mechanical microenvironments remain limited. Here, we engineered a pneumatic-driven organ-on-a-chip platform integrating six parallel culture units and a bead-embedded flexible PDMS membrane to deliver cyclic mechanical strain and enable quantitative stress–strain mapping in cardiomyocytes and skeletal muscle cells. Finite element-guided optimization ensured effective membrane deformation, and the platform generated stable and tunable cyclic strain with a strong linear relationship between applied negative pressure (50–700 mbar) and membrane stress and strain. Plasma treatment combined with type I collagen coating restored myogenic cell adhesion and growth on PDMS to levels comparable to standard culture conditions. Under 13% cyclic strain, both cardiomyocytes and skeletal muscle cells exhibited pronounced and highly uniform alignment, with cellular polarity oriented perpendicular to the stretch axis. Moreover, cyclic loading significantly enhanced the expression of contractile maturation markers, including MYH7 in cardiomyocytes and MYH6 in skeletal muscle cells (all p < 0.05), whereas expression of the differentiation regulator MyoG remained unchanged, indicating that mechanical stimulation preferentially promotes structural organization and contractile maturation rather than lineage commitment. Collectively, this quantitatively programmable organ-on-a-chip represents a bioengineered microdevice for studying myogenic mechanobiology, revealing conserved mechanosensitive alignment and maturation responses across myogenic lineages and providing a versatile framework for biomedical engineering research, disease modeling, and mechanotherapeutic screening. Full article

Background: Influenza B virus (IBV) undergoes continuous genetic mutations that can affect vaccine effectiveness and immune evasion. Although considerable research on IBV epidemiology exists globally, understanding of its genetic behavior in Saudi Arabia remains limited. This study characterized the molecular epidemiology of IBV in Riyadh, Saudi Arabia, during the 2024–2025 influenza season and evaluated compatibility with the current vaccine strain. Methods: Nasopharyngeal samples (n = 363) were collected from individuals presenting with influenza-like illness at King Khalid University Hospital in Riyadh. Detection and subtyping of IBV were performed using RT-PCR. Complete sequencing of the hemagglutinin (HA) and neuraminidase (NA) genes was conducted on confirmed IBV isolates (n = 7), followed by phylogenetic analysis, amino acid substitution mapping, and glycosylation site prediction. Results: Of the 363 samples analyzed, 68 (18.7%) tested positive for IBV, with the majority occurring in adult females aged 15–64 years. Phylogenetic analysis revealed that all seven IBV isolates belonged to the Victoria lineage under subclade V1A.3a.2, corresponding to the current vaccine strain and strains from the 2022–2023 epidemic season. However, molecular analysis identified two substitutions (D129N and D197E) located in antigenic loop-150 and 190-helix, respectively, in the HA polypeptide that distinguished our strains from vaccine strain B/Austria/1359417/2021. Importantly, the N-glycosylation site at position 169 (NKT), which was present in B/Riyadh/1/2010, has been lost in the IBV strains circulating during 2020–2025. Conclusions: While phylogenetic clade compatibility indicates potential vaccine efficacy, the identified amino acid variations and loss of the glycosylation site underscore the necessity for ongoing molecular surveillance to monitor antigenic changes and evaluate vaccine effectiveness within the Saudi Arabian population. Full article

Background/Objectives: Plasmids are key vehicles for the dissemination of antimicrobial resistance (AMR), yet their contribution to the global resistome architecture of Escherichia coli remains poorly resolved. This study aimed to quantify how plasmid backbones shape the distribution, mobility, and stabilization of resistance genes across diverse phylogenetic backgrounds. Methods: We analyze 9700 high-quality genomes spanning major phylogroups and sequence types. Plasmidome reconstruction was integrated with lineage-resolved antimicrobial resistance gene (ARG) mapping to characterize plasmid–ARG associations and evolutionary patterns. Results: Although most antimicrobial resistance genes (ARGs) are chromosomal, plasmids disproportionately encode clinically important determinants including bla_NDM-5, mcr-1.1, and multiple bla_CTX-M alleles that show strong, recurrent associations with a restricted set of backbone families, most notably IncX3, IncX4, IncI, and IncF. These conserved plasmid–gene modules recur across phylogenetic backgrounds and continental scales. We identify a marked divergence in evolutionary strategies: generalist phylogroups (A, B1, D) maintain plasmid-rich and highly diverse resistomes, whereas globally dominant Extraintestinal Pathogenic E. coli (ExPEC) clones such as ST131 and ST410 exhibit reduced plasmid dependency and frequent chromosomal integration of extended-spectrum β-lactamase (ESBL) genes, particularly bla_CTX-M-15, consistent with a shift toward vertically stabilized resistomes. By integrating plasmidome reconstruction with lineage-resolved ARG mapping, this study delivers the most extensive plasmid-focused resistome analysis to date, revealing highly modular plasmid–ARG networks structured around a small number of high-risk backbone types. These backbones account for the majority of globally relevant ARGs, including 64.6% of bla_NDM-5 and 76.4% of mcr-1.1 detections. Conclusions: Together, our findings establish plasmid lineages rather than individual genes or clones as central units of AMR dissemination and critical targets for future genomic surveillance and intervention strategies. Full article

Pigs are a major source of animal protein and an important model for studying domestication, adaptation, and the genetics of complex traits. Over the past decade, pig genomics has progressed from generating reference assemblies and variant catalogues toward reconstructing population history and interpreting phenotypic divergence with greater resolution. Improvements in reference continuity, breed-matched assemblies, and pangenome/graph representations reduce reference bias in repeat-rich and structural-variant-prone regions, strengthening cross-population comparisons and fine-mapping across cohorts. Time-stratified ancient genomes provide an explicit temporal framework for evaluating lineage turnover and gene flow and support a multi-stage, network-based view of domestication. In parallel, genetic analyses of growth, carcass composition, meat quality, and disease resilience increasingly integrate association signals with regulatory annotation, gene expression, and tissue- or stage-specific context. Across these lines of work, maintaining comparability across reference frameworks remains central, including stable coordinate systems, robust imputation resources, and reproducible approaches for structural-variant genotyping. Together, these developments support more consistent inference and interpretation while providing a clearer basis for translation in breeding and biomedical research with attention to genetic diversity. Full article

Mediator is a central transcriptional coactivator that connects sequence-specific transcription factors with RNA polymerase II to control inducible gene expression in plants. MED16 is a Mediator tail module subunit that functions as a context-dependent integrator, helping coordinate developmental programs with environmental adaptation. This review summarizes current evidence for MED16 function from structural and evolutionary perspectives to physiological outputs, with emphasis on how MED16 interacts with transcription factors and other Mediator subunits to shape RNA polymerase II engagement at target loci. In terms of development, MED16 contributes to organ growth and root system architecture, and comparative studies have revealed that it plays conserved roles in lineage-specific wiring. Under abiotic stress, MED16 supports the efficient activation of stress-inducible transcription, including cold acclimation and nutrient stress responses such as phosphate starvation-dependent root remodeling. In immunity, MED16 modulates salicylic acid- and jasmonate/ethylene-associated defence outputs and can be targeted by plant viruses, which is consistent with its role in antiviral transcriptional responses. Mechanistically, MED16 participates in cooperative and competitive interactions within the Mediator complex that tune hormone-responsive outputs, exemplified by MED25-related competition in abscisic acid signalling. We highlight key limitations and future directions, including the need for mechanistic validation beyond Arabidopsis, clearer models of dosage control in crops, improved understanding of context-dependent tail configurations, and high-resolution mapping of MED16 interaction interfaces. Full article

Intravenous delivery of recombinant adeno-associated virus serotype 9 can lead to reporter activation in cell types beyond the vasculature, but the routes enabling downstream parenchymal labeling remain unclear. Here, we provide a systematic, time-resolved map of parenchymal labeling after a single intravenous dose of rAAV9 encoding Cre recombinase under a ubiquitous promoter in healthy adult Ai9 reporter mice. Following retro-orbital administration, we quantified tdTomato-positive labeling across 25 targets at multiple time points over six months and observed durable reporter activation in several nonvascular parenchymal populations relevant to systemic gene-delivery applications. We also identify a set of parenchymal cell types that are consistently labeled in both this vascularly initiated reporter system and our prior adult VE-cadherin-driven reporter paradigm, supporting a connection to vascular exposure without asserting lineage relationships. These results nominate mechanistic routes for future disambiguation, including viral transcytosis across endothelium, endothelial cell transdifferentiation and extracellular-vesicle-mediated transfer. The dataset and methods provide a reference framework for investigators optimizing systemic delivery and interpreting downstream labeling in vivo. Full article

Diurnal birds of prey (Falconiformes and Accipitriformes) often display karyotypes that diverge markedly from the putative ancestral avian condition (2n = 80), with reduced diploid numbers and fewer microchromosome pairs driven by extensive chromosomal rearrangements. The harpy eagle (Harpia harpyja) was the first raptor analyzed by chromosome painting, revealing a karyotype (2n = 58) shaped by both microchromosome fusions and macrochromosome fissions followed by secondary fusions. However, these earlier analyses were limited in probe coverage. Here, we present a comprehensive chromosomal map of H. harpyja using multidirectional chromosome painting combined with chromosome-level genome assembly data. We integrated cross-species probes from Gallus gallus and Leucopternis albicollis with high-resolution genomic data to refine syntenic relationships and identify fission–fusion hotspots. G. gallus probes confirmed most previously described and genomically inferred associations but revealed novel features, including a new GGA1/GGA3 association and an increased number of GGA1-derived segments (five to six). Genomic data did not support previously suggested fusions involving GGA20–HHA1 or GGA12–Z. Dual-probe FISH further uncovered lineage-specific rearrangements, indicating rapid chromosomal evolution within Accipitriformes. This integrative approach clarifies harpy eagle genome organization and highlights dynamic evolutionary restructuring in raptor chromosomes. Full article

Drawing on two indigenous chicken breeds that have adapted for centuries to the hyper-arid Tarim Basin, namely the Baicheng You Chicken and Hotan Black Chicken, this study provides a high-resolution map of their gut microbiota across the duodenum, jejunum, ileum and cecum and subsequently isolates putative probiotic strains from cecal contents using conventional culture techniques. In the duodenum, Lactobacillus dominated Hotan Black Chicken (43.16%), whereas Ligilactobacillus prevailed in Baicheng You Chicken (37.03%). This segregation persisted in the jejunum, with Lactobacillus accounting for 62.55% of Hotan Black Chicken reads and Ligilactobacillus accounting for 60.76% reads in Baicheng You Chicken. The ileal core of Hotan Black Chicken remained Lactobacillus (50.63%), while Baicheng You Chicken shifted to Enterococcus (32.37%). In the cecum, both breeds converged on the Rikenellaceae RC9 gut group as the single dominant lineage (Hotan Black Chicken, 46.87%; Baicheng You Chicken, 46.23%). At the genus level, Hotan Black Chicken was enriched in Lactobacillus and Ligilactobacillus, whereas Baicheng You Chicken harbored a greater proportion of Enterococcus. Concurrently, eight strains with in vitro probiotic attributes were isolated, four from each breed, identified as Ligilactobacillus salivarius, Limosilactobacillus reuteri, Lactobacillus gallinarum, Enterococcus lactis, Enterococcus faecium, Enterococcus faecalis, and Bacillus velezensis. This study deciphers the intestinal microbiome of two native Tarim Basin chicken breeds, Hotan Black Chicken and Baicheng You Chicken, and mines them for autochthonous probiotic strains. The obtained dataset has established a foundational resource for poultry-related probiotics adapted to extremely arid environments, providing theoretical insights and practical value for poultry nutritionists in water-scarce regions in the future. Full article

Fibrosis is a hallmark of the tumor microenvironment in many solid cancers, driving tumor progression, immune evasion, and treatment resistance; however, the molecular and cellular mechanisms underlying fibrogenesis—particularly stromal–immune crosstalk across organs—remain incompletely understood, compounded by organ-specific heterogeneity and a lack of reliable immune-related biomarkers. To address this, we performed an integrative single-cell RNA sequencing (scRNA-seq) analysis of fibrotic tissues from four major organs—liver, lung, heart, and kidney—alongside non-fibrotic controls, applying unsupervised clustering, trajectory inference, cell–cell communication modeling, and gene set variation analysis (GSVA) to map the fibro-immune landscape. Our analysis revealed both conserved and organ-specific features: fibroblasts were the dominant extracellular matrix (ECM)-producing cells in liver and lung, whereas endothelial-derived stromal populations prevailed in heart and kidney. Immune profiling uncovered distinct infiltration patterns—macrophages displayed organ-specific polarization states; T cells were enriched for tissue-resident subsets in lung and mucosal-associated invariant T (MAIT) cells in liver; and B cells exhibited marked heterogeneity, including a pathogenic interferon-responsive subset prominent in pulmonary fibrosis. GSVA further identified divergent signaling programs across organs and lineages, including TGF-β/TNF-α in the heart, NOTCH/mTOR in the kidney, glycolysis/ROS in the lung, and KRAS/interferon pathways in the liver. Cell–cell communication analysis highlighted robust crosstalk between macrophages, T/B cells, and stromal cells mediated by collagen, laminin, and CXCL signaling axes. Together, this cross-organ atlas delineates a highly heterogeneous fibro-immune ecosystem in human fibrotic diseases, revealing shared mechanisms alongside organ-specific regulatory networks, with immediate translational implications for precision anti-fibrotic therapy, immunomodulatory drug repurposing, and the development of context-specific biomarkers for clinical stratification and therapeutic monitoring. Full article

MADS-box transcription factors are key regulators of plant development and environmental responses. Here, we performed an integrated phylogenomic and expression analysis of the MADS-box gene family in Capsicum annuum, identifying 97 members that fall into 52 Type I and 45 Type II genes. Comparative phylogeny, exon–intron organization, conserved motifs, and chromosomal mapping allowed classification into 15 subfamilies. Gene duplication analysis revealed that segmental duplication has been a major driver of family expansion. Expression profiling across multiple tissues, together with promoter cis-element prediction and stress-responsive transcriptome data, demonstrated that Type II genes exhibit broad and dynamic expression patterns, particularly under ABA treatment and temperature stress. A key finding of this study is the complete absence of the Mβ lineage, a Type I subfamily typically associated with gametophyte and endosperm development in other angiosperms. No Mβ-like sequences were detected in the pepper genome, and Type I genes overall showed extremely low expression, suggesting that the Mβ lineage has undergone lineage-specific evolutionary loss and that its functions may be compensated by other Type I members or by expanded Type II regulatory modules. Together, this study provides the first evidence for the evolutionary disappearance of the Mβ subfamily in Capsicum and offers a comprehensive resource for dissecting the developmental and stress-responsive roles of MADS-box genes in pepper. Full article

Background: Poultry-associated Enterococcus spp. are widespread commensals but may serve as One Health indicators when virulence-associated determinants and antimicrobial resistance co-occur. We characterized paired phenotypic and genomic profiles to delineate species-stratified virulome and resistome patterns. Methods: Isolates originated from a previously established poultry collection with MIC testing. Genotype–phenotype analyses were restricted to the whole-genome sequenced subset (n = 31). The acquired antimicrobial resistance genes were identified using the Comprehensive Antibiotic Resistance Database (CARD), and virulence-associated determinants were screened using the Virulence Factors Database (VFDB). Results were summarized as isolate-level presence/absence matrices and integrated with MIC-derived susceptible/intermediate/resistant categories. Results: The WGS subset comprised E. faecalis (n = 23) and E. faecium (n = 8) with diverse sequence types. Virulome architecture was strongly species-dependent: E. faecalis carried a broad repertoire of adhesion/biofilm-associated determinants, whereas E. faecium showed a limited set of high-confidence virulence-associated hits. Acquired resistance determinants were common across isolates, and resistome profiles displayed structured co-occurrence. Integrated analyses suggested only a modest overall association between virulence-gene burden and acquired resistome size, largely driven by species-level differences. Genotype–phenotype concordance was class-dependent, with incomplete alignment in several antimicrobial classes, consistent with mechanisms beyond the screened acquired gene set. The acquired resistance determinants detected in the WGS subset predominantly mapped to antimicrobial classes commonly used in food-producing animals (e.g., tetracyclines, macrolides, lincosamides, aminoglycosides, and phenicols), supporting interpretation in the context of production-associated antimicrobial selection rather than implying last-line clinical resistance by default. Conclusions: Poultry-derived enterococci may combine genetic features compatible with persistence/colonization and acquired antimicrobial resistance, with co-occurrence patterns shaped primarily by species/lineage background. These findings support risk-stratified One Health surveillance and targeted functional and mechanism-focused follow-up. This integrated virulome–resistome view highlights species-specific risk signatures in poultry-associated Enterococcus and identifies discordant high-level phenotypes that merit targeted mechanistic follow-up. Full article

The mitochondrial (mt) genomes of animals, including humans, are typically a single circular chromosome containing all mt genes. In several animal lineages, however, mt genomes have become fragmented, with genes distributed on multiple minichromosomes. How fragmented mt genomes are transcribed is still poorly understood. In this study, we investigated the transcription of the extensively fragmented mt genomes of the human head louse (Pediculus humanus capitis) and the human body louse (Pediculus humanus corporis). RNA-seq reads of both subspecies were retrieved from the NCBI Sequence Read Archive database and mapped to their mt genomes. The transcription level of each mt gene, minichromosome, motif, coding region and non-coding region, measured by RPKM (Reads Per Kilobase of transcript per Million mapped reads), TPM (Transcripts Per Million) or read coverage, was analysed statistically. In both subspecies, mt minichromosomes were transcribed entirely, with coding regions transcribed at much higher levels than non-coding regions. The 37 mt genes are transcribed unevenly, with rrnL, cox1, cox2, cox3 and atp6 transcribed at significantly higher levels than several other genes. Many transcription events terminate near a GC-rich motif in the non-coding regions; however, some transcription events pass this motif, leading to the transcription of entire non-coding regions. Despite the drastic difference in mt genome organisation, the human lice share several transcriptional features with humans, but also have unique features related to their fragmented mt genome organisation. The current study represents the first effort into the transcription of fragmented mt genomes. As more RNA-seq data become available, further studies on other animals with fragmented mt genomes are necessary to fully understand how genome fragmentation affects transcription. Full article

The wnt gene family encodes a group of highly conserved secreted glycoproteins that play essential roles in vertebrate development, including tissue patterning, cell differentiation, and gonadal regulation. However, the genomic organization, evolutionary dynamics, and functional roles of Wnt signaling components in flatfish remain poorly understood. In this study, we performed a comprehensive genome-wide identification, evolutionary characterization, expression profiling, and functional analysis of wnt genes in Cynoglossus semilaevis, a flatfish species exhibiting ZW/ZZ sex determination and temperature-induced sex reversal. A total of 20 wnt genes were identified and classified into 13 subfamilies, displaying conserved structural organization and phylogenetic relationships consistent with other teleosts. Chromosomal mapping revealed lineage-specific WNT clusters, including a unique wnt3–wnt7b–wnt5b–wnt16 block, as well as syntenic associations with reproduction-related genes (e.g., adipor2, sema3a, nape-pld, erc2, lamb2), suggesting coordinated genomic regulation. Tissue transcriptome analysis demonstrated strong sex- and tissue-biased expression patterns, with wnt5a predominantly expressed in ovaries and wnt5b specifically upregulated in pseudo-male testes. Functional assays revealed that knockdown of wnt5a or wnt5b induced testis-specific genes (sox9b, tesk1) and suppressed ovarian markers (foxl2, cyp19a1a), indicating antagonistic regulatory roles in gonadal fate determination. Promoter analysis identified yy1a as a selective repressor of wnt5b, but not wnt5a, providing a mechanistic basis for paralog divergence. Furthermore, pull-down combined with LC–MS/MS analysis showed that WNT5b interacts with proteins enriched in ribosome biogenesis and ubiquitin-mediated proteolysis, suggesting a role in translational regulation and protein turnover during spermatogenesis. Together, these findings establish WNT5 signaling—particularly wnt5b—as a key driver of testicular development in C. semilaevis and provide new insights into the molecular mechanisms underlying sex differentiation and sex reversal in flatfish. Full article

Neural progenitor cell (NPC) fate decisions are governed by transcriptional and signaling programmes, yet the epigenetic mechanisms stabilising early neuronal versus glial lineage trajectories remain unresolved. Here, DNA methylation landscapes in two widely used human NPC models—ReNcell VM (RVM) and ReNcell CX (RCX)—were examined under several different culture conditions to define regulatory pathways shaping lineage specification. Exploratory analyses revealed that the ReNcell lines exhibited methylation similar to primary glial populations rather than neuronal subtypes, with RCX cells positioned further along a maturation trajectory and RVM cells retaining a multipotent state. RCX cultures displayed hypomethylation of neuronal markers (DCX, ENO2, MAP2), whereas RVM cultures showed consistent GFAP hypomethylation, indicative of glial or early progenitor identity. Signaling pathways regulating lineage commitment were highlighted, including TGFβ, Wnt, and Notch signaling. Within the Notch pathway, RCX cells exhibited higher gene expression of NOTCH2 and JAG ligands, consistent with active lateral induction and a developmentally advanced state. In contrast, RVM cells exhibited higher DLL1 and NOTCH1 expression, supporting lateral inhibition and cellular heterogeneity. Knockdown of syndecan-4 (SDC4) revealed opposing effects on Notch activity. Together, these findings established DNA methylation as a determinant of lineage-specific signaling in human NPCs. Full article