Search Results (282)

Choy sum (Brassica rapa var. parachinensis) is an important vegetable crop in Brassicaceae. However, its mitochondrial genome has not been well studied. In this study, Illumina and Nanopore sequencing technologies were combined to assemble the complete mitochondrial genome of choy sum. The mitochondrial genome is a circular molecule of 219,775 bp, with a GC content of 45.23%. A total of 60 genes were annotated, including 33 protein-coding genes (PCGs), 23 transfer RNA (tRNA) genes, 3 ribosomal RNA (rRNA) genes, and one pseudogene. A total of 466 RNA editing sites were identified in the PCGs. Codon usage analysis revealed that leucine (leu) was the most frequently used amino acid. Twenty-nine codons showed a relative synonymous codon usage (RSCU) value greater than 1. Most of these preferred codons ended with A or U. A total of 308 repetitive sequences were detected, including 136 dispersed repeats, 17 tandem repeats, and 55 simple sequence repeats (SSRs). Evolutionary analysis indicated that most mitochondrial genes are under negative selection. The highest nucleotide diversity detected in the cox2 gene suggests that this gene could serve as a valuable molecular marker for mitochondrial research in the species. Homology analysis found 22 homologous fragments between the mitochondrial and chloroplast genomes of choy sum. These fragments total 13,325 bp, representing 6.06% of the mitochondrial genome. Phylogenetic analysis showed that choy sum is most closely related to B. rapa var. purpuraria. This study offers a genomic resource for genetic improvement and breeding of choy sum. It also provides molecular insights into the evolution of Brassica species. Full article

Metal nanoparticles (NP) are increasingly used in biomedical applications. Among them, silver NPs (AgNPs) are used as active components in antibacterial coatings for wound dressings, medical devices, implants, cosmetics, textiles, and food packaging. On the other hand, AgNPs can be toxic to humans, depending on the dose and route of exposure, as agents delivering silver to cells. The cysteine residues are the primary molecular targets in such exposures, due to the high affinity of Ag⁺ ions to thiol groups. The Endothelial monocyte-activating polypeptide II (EMAP II), a cleaved C-terminal peptide of the intracellular aminoacyl-tRNA synthetase multifunctional protein AIMP1, contains five cysteines exposed at its surface. This prompted the question of whether they can be targeted by Ag⁺ ions present at the AgNPs surface or released from AgNPs in the course of oxidative metabolism of the cell. We explored the interactions between recombinant EMAP II, tRNA, and AgNPs using UV-Vis and fluorescence spectroscopy, providing insight into the effects of AgNPs dissolution kinetics on interaction EMAP II with tRNA. In addition, the EMAP II fragments binding to intact AgNPs were established by heteronuclear ¹H-¹⁵N HSQC spectra utilizing a paramagnetic probe. Structural analysis of the EMAP II reveal that the 3D structure of protein was destabilized (partially denatured) by the binding of Ag⁺ ions released from AgNPs at the most exposed cysteines. Surprisingly, this effect enhanced tRNA affinity to EMAP II, lowering its $K_d$. The course of the EMAP II/tRNA/AgNP reaction was also modulated by other factors, such as the presence of Mg²⁺ ions and TCEP, a thiol-group protector used to mimic the reducing conditions of the cell. Full article

The wolf (Canis lupus) is an apex predator with high mobility and trophic plasticity, serving as a valuable indicator of helminth transmission at the wildlife–livestock interface. Given the ecological overlap between wolves and both wild and domestic ungulates in Romania, we aimed to identify and molecularly characterize cestodes from wolves’ small intestines. Between November 2022 and June 2025, small intestines from nine wolves were collected across four Romanian counties, frozen, and examined using classical parasitology (macroscopic and microscopic) and molecular methods (PCR amplification and Sanger sequencing of mitochondrial cox1, nad1, and 12S rRNA fragments). Taeniids were detected in three (33.33%) out of nine tested individuals. Genetic analyses confirmed the presence of Taenia krabbei and Taenia hydatigena—species not previously reported in wolves from Romania. This study provides the first molecular evidence of T. krabbei and T. hydatigena in wolves from Romania, and likely Eastern Europe, indicating active transmission and underscoring the need for broader surveillance of hosts to clarify their ecology and regional dynamics within a One Health context. Full article

Tarantulas (family Theraphosidae) are ecologically significant invertebrate predators in terrestrial ecosystems, but many species face threats from habitat fragmentation and unsustainable collection for the international pet trade. Brachypelma albiceps, a CITES Appendix II-listed species, lacks comprehensive mitochondrial genome characterization, limiting phylogenetic and evolutionary studies. Here, we report a complete mitochondrial genome sequence for B. albiceps (13,856 bp; GC content 32.84%) and provide detailed annotation. The genome exhibits typical metazoan mitochondrial organization, containing 13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs, with an AT-rich nucleotide composition (67.16%) characteristic of arthropod mitochondria. Comparative analyses of B. albiceps and six other Mygalomorphae species revealed strong biases toward A/T-ending codons and avoidance of G/C-ending codons. ENC–GC3s, neutrality, and PR2 analyses consistently indicate that natural selection plays a dominant role in shaping synonymous codon usage, with mutation pressure also contributing. Phylogenetic reconstruction based on 10 high-quality mitochondrial protein-coding genes from 23 spider species confirmed the placement of B. albiceps within the family Theraphosidae and its close phylogenetic relationship to Cyriopagopus species. These results provide valuable genomic resources for the Theraphosidae systematics, enhance our understanding of codon bias evolution, and provide critical DNA barcode data for forensic identification of CITES-regulated specimens in the illegal wildlife trade. Full article

Background: Gynostemma pentaphyllum (Thunb.) Makino is an important medicinal plant within the Cucurbitaceae family. Despite its economic and pharmacological importance, genomic resources for this species remain limited. Methods: We sequenced and assembled the complete mitochondrial genome of G. pentaphyllum. Comparative analyses were conducted to investigate the genomic structure, gene content, RNA editing events, and intracellular gene transfer (IGT) from chloroplasts. Additionally, phylogenomic relationships, synteny, and the selective pressure on mitochondrial genes were evaluated against related species within Cucurbitaceae. Results: The ~324 kb mitogenome has a multipartite architecture of six circular-mapping molecules. It encodes the typical complement of mitochondrial protein-coding genes, tRNAs, and rRNAs found in angiosperms. Extensive C-to-U RNA editing, including events that generate functional start and stop codons, points to substantial post-transcriptional regulation. We also detected multiple chloroplast-derived fragments, including several intact genes, indicating active intracellular gene transfer. Phylogenomic analyses of conserved mitochondrial genes place G. pentaphyllum firmly within Cucurbitaceae, clustering it with Thladiantha cordifolia and Momordica charantia, whereas synteny comparisons reveal pronounced structural rearrangements with respect to these close relatives. While most genes evolve under strong purifying selection, rps1, sdh3, and sdh4 show signatures of accelerated evolution; furthermore, haplotype networks based on conserved loci further corroborate the close affinity with T. cordifolia. Conclusions: This study provides the first high-resolution mitogenome resource for G. pentaphyllum and candidate mitochondrial markers for species authentication, evolutionary studies, and breeding in Gynostemma and related cucurbits. Full article

Rare genetic ocular diseases represent a heterogeneous group of disorders that significantly impair visual function and quality of life. Despite their clinical relevance, many of these conditions remain insufficiently characterized due to complex molecular mechanisms and diagnostic limitations. Recent advances in molecular diagnostics, particularly Next-Generation Sequencing (NGS), have enabled comprehensive and accurate identification of pathogenic variants, offering novel insights into genotype–phenotype correlations and supporting precision medicine approaches. In parallel, the use of alternative biological matrices such as tear fluid has emerged as a promising non-invasive strategy for biomarker discovery and disease monitoring. Tear-based omics, including proteomics and transcriptomics, have identified diagnostic signatures and pathogenic mediators such as non-coding RNAs, microRNAs, and tRNA-derived fragments (tRFs). Among these, tRF-1001 has shown potential both as a biomarker and therapeutic target in ocular neovascular conditions through its modulation of angiogenic pathways. The objective of this review is to show the integration of two rapidly advancing yet frequently isolated fields: next-generation sequencing-based genomics and tear-fluid molecular profiling, positioning them as complementary foundations of precision ophthalmology for rare inherited retinal and optic nerve disorders. Previous reviews have mainly concentrated on either genetic diagnosis or ocular surface biomarkers separately; however, we have introduced a convergent model wherein genomic data furnish diagnostic and prognostic clarity, while tear-omics deliver dynamic, minimally invasive assessments of disease activity, treatment efficacy, and persistent neurovascular stress. By explicitly connecting these two aspects, we have delineated how multi-matrix, multi-omics approaches can expedite early diagnosis, facilitate personalized longitudinal monitoring, and direct focused treatment interventions in rare ocular genetic illnesses. Full article

Callicarpa americana L. is a member of the Lamiaceae family with important ornamental and medicinal value. Although the chloroplast genome of Lamiaceae has been extensively studied, its mitochondrial genome remains unreported, limiting a comprehensive understanding of the phylogeny and genome evolution of Lamiaceae. In this study, the complete mitochondrial genome of C. americana was successfully assembled for the first time. The genome is 499,565 bp in length, showing a complex multi-branched closed-loop structure that contains 37 protein-coding genes, 23 tRNA genes, and 4 rRNA genes. The difference in mitochondrial genome size is relatively large compared to Orobanchaceae species, but the difference in GC content is not obvious. The expansion of genome size was mainly due to the accumulation of non-coding regions and repetitive sequences. Meanwhile, two pairs of long repetitive sequences (LR3 and LR5) mediated homologous recombination. The mitogenome was also identified; there were a total of 494 C-to-U RNA editing sites in protein-coding genes. In addition, 42 mitochondrial plastid DNA fragments (MTPTs) were detected, with a total length of 21,464 bp, accounting for 4.30% of the genome. Repeat sequence analysis showed that tetranucleotide SSR was the most abundant repeat type in the mitochondria of Lamiaceae. Phylogenetic analysis based on the alignment of 32 protein-coding gene sequences showed that Callicarpa is sister to the other eight species of Lamiaceae. This work fills an important gap by presenting the first complete mitochondrial genome of C. americana, providing an important data resource for further understanding the structural evolution, dynamic recombination mechanism, and phylogeny of the mitochondrial genome of Lamiaceae. Full article

Heteropolysaccharides, the principal bioactive constituents of the esteemed medicinal food Tremella aurantialba, remain poorly understood in both structure and function. Herein, we describe a novel heteropolysaccharide, designated TAP-2a, isolated from the fruiting bodies of T. aurantialba via multi-step column chromatography. With a molecular weight of 16.95 kDa, TAP-2a is dominated by the pyranose forms of ᴅ-galactose (ᴅ-Galp), ᴅ-glucose (ᴅ-Glcp) and ᴅ-mannose (ᴅ-Manp), accompanied by minor proportions of ᴅ-xylose (ᴅ-Xylp), ʟ-fucose (ʟ-Fucp) and glucuronic acid. Methylation-GC-MS and exhaustive 1D/2D NMR analyses revealed a backbone assembled from →6)-α-Galp-(1→, →6)-β-Glcp-(1→, and →3)-α-Manp-(1→residues, branched at →2,6)-β-Galp-(1→, →3,6)-α-Galp-(1→, and →2,3)-α-Manp-(1→residues, and terminated by β-Glcp-(1→, α-Fucp-(1→, and β-Xylp-(1→. This intricate glycosidic architecture generates an exceptionally complex mannoglucogalactan in which a Gal→Man domain is substituted at O-3 of Gal by t-β-Glcp side chains and at O-2 of Man by t-α-Fucp stubs; additionally, a discrete fragment comprising t-β-Glcp-(1→3)-β-Glcp-(1→ was identified, along with a minor branch in which t-β-Xylp is attached to O-2 of a mannose residue. Functionally, TAP-2a proved to be a potent immunomodulator, markedly enhancing the secretion of nitric oxide, interleukin-1β, interleukin-6 and tumour necrosis factor-α while concurrently up-regulating the corresponding mRNA transcripts and augmenting phagocytic capacity. These findings establish the highly elaborate heteropolysaccharides of T. aurantialba as powerful immunomodulators that underpin the fungus’s renowned medicinal efficacy. Full article

Euryhaline fishes provide excellent material for the theoretical study of the broad-spectrum adaptability of organisms and the use of low-salinity and even freshwater environments, or high-salinity and seawater environments, for the domestication of fishes. Here, we studied the molecular mechanisms of osmotic pressure regulation in a euryhaline fish, marine medaka (Oryzias melastigma). As the fish progressed from seawater to freshwater, the changes in stress indicators (cortisol—COR; malondialdehyde—MDA; reactive oxygen species—ROS; superoxide dismutase—SOD) indicated that they gradually adapted to the freshwater environment. The transcriptome analysis also showed that there were 6850 DEGs (differentially expressed genes) involved in the process. By analyzing these DEGs deeply, we screened and identified the Hnf1ba-slc12a1 signal pathway involved in osmotic pressure regulation. The results of a dual-luciferase reporter assay in HEK293T cells, as well as an overexpression experiment by in vitro cultured gill cells of O. melastigma, confirmed that Hnf1ba transcriptionally regulates the slc12a1 gene. Fragment deletion and site-directed mutagenesis assays revealed a Hnf1ba-binding sequence (GATTAATCATTTACT, located at −1877 to −1863) in the slc12a1 promoter. Based on this result, we conducted a targeted regulation experiment on the slc12a1 gene using the CRISPR-dCas9 & Sun-Tag system. The most effective activation of slc12a1 gene expression was observed in the sgRNA2 group. These results enhance our understanding of adaptation mechanisms in salt-tolerant fish and provide a reference for efficiently promoting the domestication of fish adaptive to salinity changes. Full article

Compared with capillary electrophoresis (CE), gel electrophoresis (GE) is a traditional method for the analysis of nucleic acids because of its low cost, although the operation process is complicated. The electropherogram from CE can offer more information (e.g., DNA size and its concentration) for researchers. Based on the self-built integrated biochip GE system, we proposed a computational method that converts conventional agarose GE images into CE-like fluorescence profiles for enhanced DNA analysis. The gel images were processed using an image-based algorithm involving median filtering to remove background noise and pixel-wise intensity summation along the migration axis to generate one-dimensional records of electrophoretic separations. Each DNA band in the gel was thereby transformed into a distinct fluorescence peak, reflecting its migration distance and relative intensity. To further enhance resolution and peak separation, Gaussian modeling was applied to fit the fluorescence intensity distribution, providing smoother and more distinguishable spectral peaks. To validate the method, three periodontal pathogens—Porphyromonas gingivalis (P.g), Treponema denticola (T.d), and Tannerella forsythia (T.f)—were amplified using PCR and analyzed by gel electrophoresis. The method successfully identified distinct electrophoretic patterns for the three pathogens by using a 50 bp DNA ladder as an internal calibration reference. The results demonstrate that image-based reconstruction of electrophoretic data provides a reliable, quantitative, and visually interpretable representation of DNA migration, comparable to CE output. This approach bridges a gap between traditional GE and modern capillary systems, allowing for the semi-quantitative analysis of DNA fragments without specialized CE instrument. The proposed method offers a valuable analysis method for the separation of DNA, RNA, protein and polypeptides. Full article

Transfer RNA-derived fragments (tRFs) have become a significant category of small non-coding RNAs that likely play vital roles in various cellular functions. Initially, research on small RNAs overlooked tRFs as simple byproducts of tRNA degradation, but recent findings show they are precisely produced molecules that regulate gene expression. Studies have demonstrated that tRFs regulate genes and proteins through various mechanisms, from miRNA-like targeting that relies on Argonaute (AGO) protein to lesser-known modes of action. Recent reports also suggest that tRFs are involved in multiple diseases, including cancer, where they may be utilized as biomarkers. Notably, tRFs can be transported between different cells and tissues of an organism or even across different organisms, further emphasizing their biological significance. Although evidence increasingly indicates that tRFs may function as new regulatory agents in health and disease, their biogenesis and underlying mechanisms are not yet fully understood. Conducting a thorough exploratory analysis of the tRF modes of action could be a valuable resource for advancing this growing field. Our goal in this review is to gather and examine the latest research on tRF biology, focusing on its diverse and dynamic molecular mechanisms discovered in different disease contexts, with a view toward potential applications in medicine. We aim to gain a deeper understanding of tRFs and explore their potential for new therapeutic breakthroughs by combining insights from molecular studies, disease models, and clinical research. Full article

An emerging area of microbial biology focuses on oligonucleotides excised from functional RNAs and subsequently fulfilling an independent cellular role. Some of these products are subjected to modifications that may expand their functional inventory. Here, we applied a differential analysis of intra- and extracellular RNA fragments produced by wild-type Escherichia coli and its dps-null mutant and discovered leucine tRNA fragments with random 3′-terminal extensions among oligonucleotides with Dps-dependent secretion. We observed an exclusive intracellular enrichment of modified LeuT(VPQ) tRNA fragments compared to secretomes, with abundance level dependent on growth medium and the presence of competing bacteria. To assess the pervasiveness of this phenomenon, we developed a custom computational pipeline for detecting variable RNA termini in RNA-seq data. Beyond LeuT(VPQ) tRNA fragments, several other genomic loci yielded oligos with highly heterogeneous ends, indicating that terminal elongation, most prevalent in LeuT(VPQ), is not exclusive to these fragments. Ex vivo testing using synthetic LeuT(VPQ) analogs revealed their stimulatory effect on the persistence of multiple taxa in an artificial microbiome, which was attenuated by 3′-end elongation. We propose that non-template extensions may serve to broaden the spectrum of target molecules for elimination of unused mRNAs by an interference-like mechanism or to generate sequences absent from the E. coli genome as part of a primitive defense system. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly prevalent condition linked to obesity, diabetes, and metabolic syndrome, and can progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Current diagnostic standards such as liver biopsy are invasive and unsuitable for routine screening. Liquid biopsy, particularly through analysis of extracellular RNAs (exRNAs), including microRNAs (e.g., miR-122, miR-21, miR-34a), long non-coding RNAs, and tRNA-derived fragments, offers a promising non-invasive alternative. These exRNAs, released from hepatocytes and carried in blood via extracellular vesicles or protein complexes, can be detected using techniques like RNA sequencing, qRT-PCR, and droplet digital PCR. These biomarkers correlate with histologic severity, fibrosis stage, and treatment response, and have shown promising diagnostic utility; however, their performance may differ across various populations and disease stages. Despite their potential, clinical translation is limited by a lack of standardization and large-scale validation. This review outlines recent advances in exRNA-based diagnostics for MASLD and MASH, emphasizing their role in early detection, disease monitoring, and the shift toward personalized hepatology. Full article

Transfer RNA-derived small RNAs (tDRs) are increasingly being recognized as versatile regulators, yet their physiological landscape remains poorly charted. We analyzed tDR expression in seven adult mouse tissues to explore tissue-specific tDR enrichment using a tDR-optimized library preparation methodology. We catalogued 26,901 unique nuclear tDRs (ntDRs) and 5114 mitochondrial tDRs (mtDRs). Clustering analysis segregated the tissues, with the spleen and lungs forming a distinct immune cluster. Tissue-versus-all and pairwise differential analysis showed the spleen harboring unique ntDRs and mtDRs. Tissue-enriched tDRs arose from specific isoacceptor and isodecoder tRNAs, independent of mature tRNA abundance, suggesting selective biogenesis rather than bulk turnover. G-quadruplex prediction revealed a pronounced enrichment of potentially quadruplex-forming ntDRs in the kidneys, heart, and spleen, predominantly derived from i-tRFs and tRF3 fragments, suggesting structure-dependent functions in immune regulation. We also benchmarked our library strategy against the PANDORA-seq method. Despite comparable or lower sequencing depth, our method detected ~3–10-fold more unique ntDRs and we observed a clearer representation of tRF-3 fragments and greater isotype diversity. Our tissue atlas and improved tDR sequencing method reveal extensive tissue-specific heterogeneity in tDR biogenesis, sequencing, and structure, providing a framework for understanding the context-dependent regulatory roles of tDRs. Full article

Polystyrene microplastic (MP) and its co-existing contaminants may exert different toxic effects on its surrounding aquatic organisms. In order to detect the intestinal harmful responses, tilapia were subjected to exposure with 75 nm of MPs, 100 ng·L⁻¹ of sulfamethoxazole (SMZ), 5 ng·L⁻¹ of BDE153, and combinations thereof over periods of 2, 4, and 8 days. Enzymatic assays, transcriptomics, proteomics, and metabolomics were employed to evaluate intestinal histopathological effects. Results showed that significant reductions were observed in ATP, ROS, SOD, EROD, lipid metabolism-related enzymes, pro-inflammatory cytokines (TNFα and IL-1β), and apoptosis marker caspase 3 across all groups at day 8. Histological evaluation revealed diminished goblet cell density, with distinct vacuole formation in the BDE153+MPs group. KEGG pathway analysis highlighted disruptions in endocytosis, MAPK signaling, phagosome formation, and actin cytoskeleton regulation. Proteomic findings indicated notable enrichment in endocytosis (decreased sorting nexin-2; increased Si:dkey-13a21.4), MAPK/PPAR signaling, protein processing in the endoplasmic reticulum (Sec61 subunit gamma), and cytoskeletal modulation (reduced fibronectin; elevated activation peptide fragment 1), with or without SMZ and BDE153. Metabolomic profiling showed significant alterations in ABC transporters, aminoacyl-tRNA biosynthesis, protein digestion and absorption, and linoleic acid metabolism. In summary, these findings suggest that BDE153 and MPs synergistically exacerbate intestinal damage and gene/protein expression over time, while SMZ appears to exert an antagonistic, mitigating effect. Full article