DNA, Volume 5, Issue 4 (December 2025) – 8 articles

Myalgic Encephalomyelitis (ME), also known as chronic fatigue syndrome (CFS), is a debilitating and heterogeneous disorder marked by persistent fatigue, post-exertional malaise, cognitive impairment, and multisystem dysfunction. Despite its prevalence and impact, the molecular mechanisms underlying ME remain poorly understood. This review synthesizes current evidence on the role of DNA, both nuclear and mitochondrial, in the susceptibility and pathophysiology of ME. We examined genetic predispositions, including familial clustering and candidate gene associations, and highlighted emerging insights from genome-wide and multi-omics studies. Mitochondrial DNA variants and oxidative stress-related damage are discussed in relation to impaired bioenergetics and symptom severity. Epigenetic modifications, particularly DNA methylation dynamics and transposable element activation, are explored as mediators of gene–environment interactions and immune dysregulation. Finally, we explored the translational potential of DNA-based biomarkers and therapeutic targets, emphasizing the need for integrative molecular approaches to advance diagnosis and treatment. Understanding the DNA-associated mechanisms in ME offers a promising path toward precision medicine in post-viral chronic diseases. Full article

Background/Objectives: DNA interstrand cross-links (ICLs) mark one of the most deleterious lesions that can preclude strand separation required for essential cellular processes. Efforts to discover ICL-inducing agents and endogenous substrates for ICL repair pathways have led to the identification of structurally diverse ICLs produced by reactive aldehydes and abasic sites, among others. While several studies point to UV rays as ICL-inducing agents, UV ray-induced ICL formation from biologically relevant DNA lesions has been rarely reported. We conjectured that solar radiation-induced reactive oxygen species may give rise to ICLs via further oxidation of DNA lesions with lower redox potential (e.g., 8-oxoadenine (oxoA)). Here, we present the discovery of ICL production via light-induced modification of the major oxidative adenine lesion oxoA. Methods/Results: In the absence of a photosensitizer, both UVC and UVB rays, but not UVA and visible rays, trigger the formation of oxoA-G ICLs, albeit in low yields. By contrast, the inclusion of the naturally occurring photosensitizer riboflavin in the cross-linking reaction makes UVA and visible rays readily generate oxoA-G ICLs, suggesting solar radiation facilitates the formation of oxoA ICLs in vivo. Conclusions: The plausible oxoA-G ICL formation mechanism concerns the further oxidation of oxoA into an iminoquinone, followed by the nucleophilic attack of the opposite guanine on the iminoquinone. OxoA-G ICLs represent rare examples of ICLs produced by photosensitization. These results will contribute to the discovery of a novel form of ICLs induced by solar radiation. Full article

Glucosinolates (GSLs) are nitrogen- and sulfur-containing secondary metabolites central to the defense, development, and environmental responsiveness of Brassicaceae species. While the enzymatic steps and transcriptional networks underlying GSL biosynthesis have been extensively characterized, mounting evidence reveals that chromatin-based processes add a critical, yet underexplored, layer of regulatory complexity. Recent studies highlight the roles of DNA methylation, histone modifications, and non-coding RNAs in modulating the spatial and temporal expression of GSL biosynthetic genes and their transcriptional regulators in response to developmental cues and environmental signals. This review provides a comprehensive overview of GSL classification, biosynthetic pathway architecture, transcriptional regulation, and metabolite transport, with a focus on emerging epigenetic mechanisms that shape pathway plasticity. We also discuss how these insights may be leveraged in precision breeding and epigenome engineering, including the use of CRISPR/dCas9-based chromatin editing and epigenomic selection, to optimize GSL content, composition, and stress resilience in cruciferous crops. Integrating transcriptional and epigenetic regulation thus offers a novel framework for the dynamic control of specialized metabolism in plants. Full article

Background/Objectives: Environmental DNA (eDNA) is increasingly recognised as a powerful molecular tool for biodiversity monitoring, enabling the detection of species through trace genetic material found in environmental samples. This study investigates the utility of eDNA analysis for identifying vertebrate marine species in the central Mediterranean, with a focus on taxa that serve as ecological indicators to local ecosystems. Methods: Seawater samples were collected from nine sites around the Maltese Islands between May and August 2021, at depths ranging from 2 to 5 m. Samples were filtered and DNA was extracted, amplified and sequenced. The resulting sequences were processed through a bioinformatics pipeline, clustered into molecular operational taxonomic units (MOTUs) and assigned taxonomic identities using reference databases. Results: This study led to the detection of 70 MOTUs, including ecologically important species such as the loggerhead turtle (Caretta caretta), the striped dolphin (Stenella coeruleoalba) and the bottlenose dolphin (Tursiops truncatus), underscoring the method’s effectiveness in the detection of taxa of conservation value. Additionally, we detected a number of overlooked Blenniidae and Gobiidae taxa and deep-water or rarely encountered species such as the ocean sunfish (Mola mola), Cornish blackfish (Schedophilus medusophagus), Haifa grouper (Hyporthodus haifensis) and Madeira lantern fish (Ceratoscopelus maderensis). eDNA of the invasive dusky spinefoot (Siganus luridus) and that of the lumpfish (Cyclopterus lumpus), a species not previously recorded in Maltese waters, was also detected during this study. The latter’s detection highlights the potential of this methodology as an early detection tool for biological invasions. Conclusions: These findings support the integration of eDNA surveillance into marine biodiversity monitoring frameworks, particularly within marine protected areas to monitor native indicator taxa and assess the effectiveness of conservation measures, but also in ports and bunkering zones, where the risk of alien species introduction is elevated, with potential subsequent invasive species expansion that impacts native species and habitats. Full article

Background/Objectives: Mutations in NACHT, LRR and PYD domain-containing protein 2 (NLRP2) and NLRP7 genes, members of the NOD-like receptor (NLR) family of innate immune sensors, result in recurrent miscarriages and reproductive wastage in women. These genes have been identified to be maternal effect genes in humans and mice regulating early embryo development. Previous research in vitro suggests that NLRP2 and NLRP7 regulate DNA methylation and/or immune signaling through inflammasome formation. However, the exact mechanisms underlying NLRP2 and NLRP7 function are not well defined. Methods: To determine the interacting proteins required for NLRP2/NLRP7-mediated regulation of DNA methylation, yeast 2-hybrid screens, coimmunoprecipitation, and FRET studies were performed and verified the ability of novel protein interactions to affect global DNA methylation by 5-methylcytosine-specific ELISA. Results: Various methodologies employed in this research demonstrate a novel protein interaction between human ErbB3-binding protein 1 (EBP1, also known as proliferation-associated protein 2G4 (PA2G4) and NLRP2 or NLRP7. In addition, NLRP2 and NLRP7 regulate EBP1 gene expression. Functionally, global DNA methylation levels appeared to decrease further when NLRP2 and NLRP7 were co-expressed with EBP1, although additional studies may need to confirm the significance of this effect. Conclusions: Since EBP1 is implicated in apoptosis, cell proliferation, DNA methylation, and differentiation, our discovery significantly advances our understanding of how mutations in NLRP2 or NLRP7 may contribute to reproductive wastage in women through EBP1. Full article

Multiple sclerosis (MS) is a chronic autoimmune neurodegenerative disorder characterized by progressive demyelination and axonal degeneration within the central nervous system, driven by complex genomic and epigenomic dysregulation. Its pathogenesis involves aberrant DNA methylation patterns at CpG islands of numbers of genes like OLIG1 and OLIG2 disrupting protein expression at myelin with compromised oligodendrocyte differentiation. Furthermore, histone modifications, particularly H3K4me3 and H3K27ac, alter the promoter regions of genes responsible for myelination, affecting myelin synthesis. MS exhibits chromosomal instability and copy number variations in immune-regulatory gene loci, contributing to the elevated expression of genes for pro-inflammatory cytokines (TNF-α, IL-6) and reductions in anti-inflammatory molecules (IL-10, TGF-β1). Vitamin D deficiency correlates with compromised immune regulation through hypermethylation and reduced chromatin accessibility of vitamin D receptor (VDR) dysfunction and is reported to be associated with dopaminergic neuronal loss. Vitamin D supplementation demonstrates therapeutic potential through binding with VDR, which facilitates nuclear translocation and subsequent transcriptional activation of target genes via vitamin D response elements (VDREs), resulting in suppression of NF-κB signalling, enhancement of regulatory T-cell (T_reg) responses due to upregulation of specific genes like FOXP3, downregulation of pro-inflammatory pathways, and potential restoration of the chromatin accessibility of oligodendrocyte-specific gene promoters, which normalizes oligodendrocyte activity. Identification of differentially methylated regions (DMRs) and differentially expressed genes (DEGs) that are in proximity to VDR-mediated gene regulation supports vitamin D supplementation as a promising, economically viable, and sustainable therapeutic strategy for MS. This systematic review integrates clinical evidence and eventual bioinformatical meta-analyses that reference transcriptome and methylome profiling and identify prospective molecular targets that represent potential genetic and epigenetic biomarkers for personalized therapeutic intervention. Full article

Plants have evolved a complex, multilayered immune system that integrates molecular recognition, signaling pathways, epigenetic regulation, and small RNA-mediated control. Recent studies have shown that DNA-level regulatory mechanisms, such as RNA-directed DNA methylation (RdDM), histone modifications, and chromatin remodeling, are critical for modulating immune gene expression, allowing for rapid and accurate pathogen-defense responses. The epigenetic landscape not only maintains immunological homeostasis but also promotes stress-responsive transcription via stable chromatin modifications. These changes contribute to immunological priming, a process in which earlier exposure to pathogens or abiotic stress causes a heightened state of preparedness for future encounters. Small RNAs, including siRNAs, miRNAs, and phasiRNAs, are essential for gene silencing before and after transcription, fine-tuning immune responses, and inhibiting negative regulators. These RNA molecules interact closely with chromatin features, influencing histone acetylation/methylation (e.g., H3K4me3, H3K27me3) and guiding DNA methylation patterns. Epigenetically encoded immune memory can be stable across multiple generations, resulting in the transgenerational inheritance of stress resilience. Such memory effects have been observed in rice, tomato, maize, and Arabidopsis. This review summarizes new findings on short RNA biology, chromatin-level immunological control, and epigenetic memory in plant defense. Emerging technologies, such as ATAC-seq (Assay for Transposase-Accessible Chromatin using Sequencing), ChIP-seq (Chromatin Immunoprecipitation followed by Sequencing), bisulfite sequencing, and CRISPR/dCas9-based epigenome editing, are helping researchers comprehend these pathways. These developments hold an opportunity for establishing epigenetic breeding strategies that target the production of non-GMO, stress-resistant crops for sustainable agriculture. Full article

Background/Objectives: Intrinsically disordered protein regions (IDRs) are difficult to study due to their flexible nature and transient interactions. Computational folding using AlphaFold may offer one way to explore potential folding of these regions under various conditions. Human DNA topoisomerase IIα (TOP2A) is an essential enzyme involved in regulating DNA topology during replication and cell division. TOP2A has an IDR at the C-terminal domain (CTD) that has been shown to be important for regulating TOP2A function, but little is known about potential conformations that it may undertake. Methods: Utilizing the AlphaFold 3 (AF3) model by way of AlphaFold Server, TOP2A was folded as a dimer first without and then with 29 literature-supported post-translational modifications (PTMs) and DNA to observe whether there is predicted folding. Results: TOP2A CTD does not fold in the absence of PTMs. With the addition of PTMs, however, the CTD is predicted to fold into a globular bundle of loops and α-helices. While DNA alone did not induce folding, in the presence of PTMs, DNA ligands increased helicity of the folded CTD and caused it to interact at different core domain interfaces. In addition, DNA is predicted to enable folding of the TOP2A CTD in the presence of fewer PTMs when compared to the absence of DNA. Conclusions: AF3 predicts the folding of TOP2A CTD in the presence of specific PTMs, and this folding appears to shift to allow binding to DNA in functionally relevant regions. These studies provide predicted folding patterns that can be tested by biochemical approaches. AF3 may support the development of testable hypotheses regarding IDRs and enables researchers to model protein-DNA interactions. Full article