Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “nanopore sequencing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Enhanced cleavage of genomic CCR5 using CASX2Max.

Development of novel CRISPR/Cas systems enhances opportunities for gene editing to treat infectious diseases, cancer, and genetic disorders. CasX2 (PlmCas12e) belongs to the class II CRISPR system derived from Planctomycetes, a non-pathogenic bacterium present in aquatic and terrestrial soils and offers several advantages as a potential therapeutic CRISPR system over Streptococcus pyogenes Cas9 (SpCas9) and Staphylococcus aureus Cas9 (SaCas9). These advantages include its smaller size, distinct protospacer adjacent motif (PAM) requirements, staggered cleavage cuts that promote homology-directed repair, and the absence of pre-existing immunity in humans. We compared the cleavage efficiency and double-stranded break repair characteristics between CasX2 and CasX2Max, a recently generated CasX2 variant with three amino acid substitutions, for targeting CCR5, a gene that encodes the CCR5 receptor important for HIV-1 infection. Two single guide RNAs (sgRNAs) were designed that flank the 32 bases deleted in the natural CCR5 ∆32 mutation. Nanopore sequencing demonstrated that CasX2 using sgRNAs with spacers of 17 nucleotides (nt), 20 nt or 23 nt in length were ineffective at cleaving genomic CCR5. In contrast, CasX2Max using sgRNAs with 20 nt and 23 nt spacer lengths, enabled cleavage of genomic CCR5. Structural modelling indicated that two of the CasX2Max amino acid substitutions enhanced sgRNA-DNA duplex stability, while the third improved DNA strand alignment within the catalytic site. These structural changes likely underlie the increased activity of CasX2Max in cellular gene excision. In sum, CasX2Max consistently outperformed native CasX2 across all assays and represents a superior gene-editing platform for therapeutic applications.

Humans↗

Detection of lymphocytic choriomeningitis virus (LCMV) in the common house mice (Mus musculus) in Italy: an underrecognized threat to human health.

Lymphocytic choriomeningitis virus (LCMV) is a neglected zoonotic pathogen primarily transmitted by the house mouse (Mus musculus). Despite being an underestimated zoonotic threat in Europe, LCMV lacks comprehensive surveillance. In this study, we report the first molecular detection and full genomic characterization of LCMV in Italy. Between May and November 2021, 107 rodents were captured on livestock farms in the Piedmont Region and screened for arenaviruses using a pan-arenavirus RT-PCR assay. LCMV RNA was detected in three Mus musculus specimens (3.5%), all originating from two neighboring farms. Viral presence was confirmed by LCMV-specific qRT-PCR. Complete S and L genome segments were successfully obtained from one sample using a combination of RT-PCR and nanopore sequencing. Phylogenetic analyses placed the Italian strain within LCMV lineage I, clustering with strains previously detected in Europe. Host genetic analysis confirmed that infected mice belonged to the subspecies Mus musculus domesticus.IMPORTANCEThis study provides the first molecular evidence and complete genomic characterization of Lymphocytic choriomeningitis virus (LCMV) in Italy in its primary reservoir, Mus musculus. The identification of LCMV at the livestock-wildlife interface suggests a significant anthropozoonotic risk, particularly for farm workers. These findings emphasize the urgent necessity for integrated molecular surveillance and increased clinical awareness to better define the public health impact of LCMV in Italy.

Animals↗

Phylogenetic diversity and molecular evolution of Hantaan virus harbored by Apodemus chejuensis on Jeju Island, Republic of Korea, 2022-2023.

BACKGROUND: Hantaan virus (HTNV), hosted by Apodemus spp., is a well-recognized causative agent of hemorrhagic fever with renal syndrome (HFRS) and poses a crucial global public health concern. Based on the current evidence, HTNV carried by A. chejuensis is proposed as the likely etiological agent of HFRS on Jeju Island, Republic of Korea (ROK). METHODOLOGY/PRINCIPAL FINDINGS: In this study, 50 small mammals were collected from five locations in Seogwipo-si and Jeju-si on Jeju Island, ROK, during 2022-2023. Serological and molecular analyses revealed HTNV prevalence rates of 34% (16/47) and 27.7% (13/47), respectively. Using a multiplex polymerase chain reaction-based nanopore sequencing approach, nine complete HTNV genomes were sequenced from the lung tissues of A. chejuensis, representing the first comprehensive genomic characterization of HTNV from Seogwipo-si (Hogeun-dong) and Jeju-si (Sangdae-ri). Phylodynamic analyses suggest evolutionary divergence and phylogeographic diversity, with four unique amino acid substitutions identified in HTNV genomes from Seogwipo-si. CONCLUSION/SIGNIFICANCE: This study provides important insights into the genomic surveillance, genetic diversity, and evolutionary dynamics of orthohantaviruses, which are essential for guiding effective public health strategies to control and prevent future HFRS outbreaks in the ROK.

Animals↗

Characterization of METTL3/14-mediated m6A modification in human transcriptome using Nanopore direct RNA sequencing.

Post-transcriptional RNA modifications modulate diverse aspects of RNA metabolism. N6-methyladenosine (m6A), one of the most abundant internal RNA modifications, is deposited by the core methyltransferase complex, METTL3 and METTL14. Oxford Nanopore Technologies (ONT) platform permits direct, single RNA molecule sequencing while preserving native modifications. However, without rigorous benchmarking, the accuracy and reproducibility of modification detection remain uncertain. Here, we leveraged ONT to comprehensively profile bona fide m6A modifications in cellular RNAs at single-nucleotide resolution by integrating two direct RNA sequencing chemistries (RNA002 and RNA004) with the m6Anet and Dorado modification-detection models. We independently depleted METTL3 and METTL14 in human cells and rigorously validated modification calls through several assays and independent orthogonal methods (GLORI and miCLIP). We find that Dorado detected a higher number of m6A events and enabled simultaneous detection of other RNA modifications (5-methylcytosine, pseudouridine, and inosine). Pairing Dorado with an in vitro transcribed, unmodified control under stringent filtering, we provide compelling evidence supporting a global reduction in m6A sites and stoichiometry within coding sequences and across genes, particularly in highly modified genes and sites, and at consensus DRACH motifs. We report a differential and complex regulation of modified transcripts, accompanied by a global reduction in poly(A) tail length. Notably, METTL3 and METTL14 depletion produced distinct transcript-specific effects, supporting non-redundant roles within the m6A writer complex. Together, our study illustrates a notable advancement of ONT capabilities and establishes a robust transcriptome-wide framework for RNA modification detection, thereby laying the groundwork for exploring the contribution of METTL3/METTL14 to cellular functions and disease.

Humans↗

Sex differences in MAGEL2 gene promoter methylation in high functioning autism - trends from a pilot study using nanopore Cas9 targeted long read sequencing.

BACKGROUND: MAGEL2 is an autism susceptibility gene whose deficiency has been associated with autism-related behaviors in animal models and in syndromic human autism spectrum disorders (ASDs) such as Schaaf-Yang syndrome, but has not been studied in the broader autism spectrum. Given the capabilities of long-read sequencing technologies, this pilot study used a targeted nanopore sequencing approach to simultaneously examine MAGEL2 DNA sequence and methylation in adults with high-functioning autism (HFA) compared to neurotypical controls (NC). METHODS: Using DNA extracted from peripheral blood, Cas9-targeted nanopore DNA sequencing was used to analyze MAGEL2, including its entire regulatory construct (chr15:23639316-23651466), for sequence variation and 5-methyl-cytosine (5mC) modification in a cohort of adults with HFA compared to sex- and age-matched NC. Given the known sex differences in ASD and MAGEL2 KO animal models, results were further analyzed by sex. RESULTS: 20 adults with HFA (10 males, 10 females) and 20 NC were included. While there were no overall differences in MAGEL2 DNA sequence and 5mC modification between HFA and NC, we found a significant difference in MAGEL2 gene promoter methylation between males and females with HFA and NC of both sexes, with HFA males tending to show hypomethylation in a 300 bp long differentially methylated region (chr15:23647640-23647939) around the MAGEL2 transcription start site. CONCLUSIONS: In this pilot study utilizing nanopore Cas9 targeted DNA sequencing, significant sex-specific differences in MAGEL2 gene promoter methylation were identified in male adults with HFA in comparison to control groups, suggesting the potential for sex-specific epigenetic differences. However, further replication in larger cohorts is required to validate these findings.

Humans↗

Performance of the IR Biotyper, Nanopore, and Illumina sequencing to discriminate Escherichia coli strains originating from poultry.

UNLABELLED: Escherichia coli is a highly diverse bacterial species that includes avian pathogenic E. coli (APEC), one of the most prevalent causative agents of disease in poultry worldwide. Rapid and accurate discrimination of E. coli strains is essential for outbreak management, antimicrobial resistance surveillance, and vaccine development. In this study, we compared the performance of Fourier Transform Infrared (FTIR) spectroscopy using the IR Biotyper system with Nanopore and Illumina whole-genome sequencing (WGS) for typing 200 E. coli isolates, originating from four poultry rearing farms in the Netherlands. From each farm, we sampled 10 one-day-old meat type rearing chicks, and from every chick, we isolated 5 E. coli strains. FTIR clustering showed strong concordance with WGS-based classifications, particularly serotyping and core-genome similarity determined by PopPUNK analysis (Adjusted Rand Index 0.75-0.92). While Nanopore and Illumina sequencing provided the highest genetic resolution, FTIR offered a faster (max 6 vs 12-28 days for 200 isolates) and more cost-effective alternative for assessing clonality. Across all methods, multiple strains were detected per farm, whereas most birds carried a single dominant E. coli strain. Our findings demonstrate that FTIR provides a reliable and scalable phenotypic method for rapid strain discrimination in E. coli, complementing WGS in diagnostic, surveillance, and epidemiological settings where speed and throughput are critical. IMPORTANCE: Escherichia coli is a major pathogen in poultry and a potential zoonotic risk for humans. Rapid and accurate discrimination of avian pathogenic E. coli (APEC) strains is critical for outbreak management, antimicrobial resistance surveillance, and the design of effective autogenous vaccines. In this study, we compared Fourier Transform Infrared (FTIR) spectroscopy with Nanopore and Illumina whole-genome sequencing for strain typing of E. coli isolates originating from poultry. The results show that FTIR provides comparable clustering accuracy to genomic approaches at a fraction of the time and costs. This work demonstrates that FTIR can serve as a practical, high-throughput alternative for routine monitoring of E. coli in veterinary diagnostics and food safety of poultry meat, enabling faster decision-making and more targeted interventions across the poultry production chain.

Animals↗

New insights on Plasmodium gene expression from direct RNA sequencing.

Oxford Nanopore Technology (ONT) direct RNA sequencing enables the sequencing of native RNA molecules without cDNA conversion. The long-read approach captures full-length reads spanning entire genes and has transformed the study of gene expression in Plasmodium parasites by enabling analysis of untranslated regions, isoforms, and alternative splicing. In addition, ONT provides unique insights into non-coding RNAs, RNA modifications, and polyadenylated tail dynamics, which are expanding our understanding of post-transcriptional regulation in Plasmodium, including processes beyond translational repression in gametocytes and sporozoites. Here, we discuss the past and future applications of direct RNA sequencing in Plasmodium research and highlight its advantages, limitations, and future prospects.

Oxford Nanopore Technology↗

scnanoseq: an nf-core pipeline for Oxford Nanopore single-cell RNA-sequencing.

MOTIVATION: Recent advancements in long-read single-cell RNA sequencing (scRNA-seq) have facilitated the quantification of full-length transcripts and isoforms at the single-cell level. Historically, long-read data would need to be complemented with short-read single-cell data in order to overcome the higher sequencing errors to correctly identify cellular barcodes and unique molecular identifiers. Improvements in Oxford Nanopore sequencing, and development of novel computational methods have removed this requirement. Though these methods now exist, the limited availability of modular and portable workflows remains a challenge. RESULTS: Here, we present, nf-core/scnanoseq, a secondary analysis pipeline for long-read single-cell and single-nuclei RNA that delivers gene and transcript-level quantification. The scnanoseq pipeline is implemented using Nextflow and is built upon the nf-core framework, enabling portability across computational environments, scalability and reproducibility of results across pipeline runs. The nf-core/scnanoseq workflow follows best practices for analyzing single-cell and single-nuclei data, performing barcode detection and correction, genome and transcriptome read alignment, unique molecular identifier deduplication, gene and transcript quantification, and extensive quality control reporting. AVAILABILITY AND IMPLEMENTATION: The source code, and detailed documentation are freely available at https://github.com/nf-core/scnanoseq and https://nf-co.re/scnanoseq under the MIT License. Documentation for the version of nf-core/scnanoseq used for this paper, including default parameters and descriptions of output files are available at https://nf-co.re/scnanoseq/1.1.0.

Single-Cell Analysis↗

Applicability of Nanopore-only whole-genome sequencing for Pseudomonas aeruginosa outbreak investigation in the ICU setting: a multicentric study.

UNLABELLED: Pseudomonas aeruginosa outbreaks frequently occur in intensive care units (ICUs). In particular, ICU patients requiring mechanical ventilation are vulnerable to P. aeruginosa ventilator-associated pneumonia, which is associated with high morbidity and mortality. Fast and accurate genotyping during the early stage is crucial to document and manage P. aeruginosa outbreaks at the ICU. In this study, we have evaluated the applicability of Oxford Nanopore whole-genome sequencing (WGS) for outbreak investigation and antimicrobial resistance (AMR) prediction. To evaluate whether a Nanopore-only WGS workflow was able to reproduce Illumina-confirmed transmission clusters, 19 P. aeruginosa isolates from ICUs at UZ Brussels (Belgium) that were previously sequenced with Illumina were sequenced using a Nanopore-only workflow based on the latest V14 chemistry, followed by bioinformatic analysis via BugSeq and MBioSEQ Ridom Typer. Although both bioinformatic platforms showed high concordance between Illumina and Nanopore data, MBioSEQ Ridom Typer yielded the lowest allelic distance (maximum one cgMLST allele), confirming all outbreak clusters. When applying the Nanopore-only workflow to longitudinally collected isolates, low genetic heterogeneity (maximum three cgMLST alleles) was observed between isolates from the same patient. WGS and subsequent outbreak analysis of 65 respiratory P. aeruginosa isolates collected from 38 different ICU patients across six Belgian hospitals during a 9-month period showed no intra- or inter-hospital transmission. When the Nanopore-only WGS data were used to predict AMR, there was high categorical agreement (95%) between AMR genotype and phenotype. These findings highlight the potential of Nanopore WGS as a rapid and accurate tool for outbreak investigation of P. aeruginosa. IMPORTANCE: In recent years, Nanopore sequencing has found its way to clinical laboratories because of its affordability, scalability, and, most importantly, its ability to obtain sequencing results in near-real time. However, despite improved raw read accuracies with the latest generation R10.4.1 flow cells, the question remains whether the achieved accuracy is sufficient for accurate bacterial outbreak investigation, particularly in high-risk settings such as intensive care units (ICUs). In this study, we show that Nanopore-only whole-genome sequencing (WGS) is able to match Illumina-only WGS in terms of accuracy for Pseudomonas aeruginosa outbreak investigation in the ICU setting, although important sequence type-dependent and even strain-specific methylation issues need to be resolved in order to guarantee this accuracy. By providing a fast and accurate workflow for reliable P. aeruginosa outbreak investigation, this study could pave the way for large-scale implementation of Nanopore-only WGS, leading to faster outbreak response times.

Humans↗

A Step-by-Step Guide to Sequencing and Assembly of Complete Bacterial Genomes Using the Oxford Nanopore MinION.

The Oxford Nanopore (ONT) MinION enables sequencing of longer DNA/RNA fragments compared to other sequencers, such as Illumina, etc. This nanopore method provides distinct advantages for generating complete genome assemblies from microorganisms. Specifically, the R9.4 flow cells used for MinION sequencing have much lower error rates compared with earlier versions of the ONT platform. Coupled with base calling using Dorado software, higher-quality long reads can now be generated for complete bacterial genome assembly. In this chapter, we describe a detailed MinION method to assemble a complete genome from a microorganism, polish the final assembly, and evaluate the genome quality using various software tools. Because of the low cost for MinION sequencing, this platform could be an asset for virtually any laboratory interested in generating complete genomes from microorganisms.

Genome, Bacterial↗

Dogme: a nextflow pipeline for reprocessing nanopore RNA and DNA modifications.

MOTIVATION: Oxford Nanopore (ONT) sequencing allows for the direct detection of RNA and DNA modifications from unamplified nucleic acids, which is a significant advantage over other platforms. However, the rapid updates to ONT basecalling models and the evolving landscape of computational tools for modification detection bring about challenges for reproducible and standardized analyses. To address these challenges, we developed Dogme to automate basecalling, alignment, modification detection, and transcript quantification. Dogme automates the reprocessing of ONT POD5 files by integrating basecalling using Dorado, read mapping using minimap2 and subsequent analysis steps such as running modkit. The pipeline supports three major types of sequencing data-direct RNA (dRNA), complementary DNA (cDNA), and genomic DNA (gDNA). Dogme facilitates detection of diverse RNA modifications supported by Dorado such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), inosine, pseudouridine, 2'-O-methylation (Nm) and DNA methylation, while concurrently quantifying full-length transcript isoforms LR-Kallisto for transcript quantification for dRNA and cDNA. RESULTS: We applied Dogme to three separate mouse C2C12 myoblast replicates using direct RNA sequencing on MinION flow cells. We detected 96 603 m6A, 43 476 m5C, 8829 inosine, 10 055 pseudouridine, and 30 320 Nm sites in three biological replicates. The pipeline produced reproducible modification profiles and transcript expression levels across replicates, demonstrating its utility for integrative long-read transcriptomic and epigenomic analyses. AVAILABILITY AND IMPLEMENTATION: Dogme is implemented in Nextflow and is freely available under the MIT license at https://github.com/mortazavilab/dogme, with documentation provided for installation and usage.

RNA↗

Complete genome of multiply antibiotic resistant ST10 Acinetobacter baumannii isolate NL6 from Vietnam and relationship to available ST10 genomes.

The genome of NL6, a multiply antibiotic-resistant Acinetobacter baumannii ST10:KL49:OCL2 carriage isolate from Vietnam, was sequenced using Nanopore technology, and complete chromosome and plasmid sequences were assembled from the long reads and available short reads. Resistance genes and their locations were identified, and transfer of a conjugative plasmid carrying several resistance genes into a new host was tested. The acquired resistance genes in NL6 were distributed between the chromosome and two of three plasmids present. The chromosome carries multiple copies of several insertion sequences, an incomplete copy of the ISAba1-bounded Tn6250 that includes the sul2 and strAB genes, and an integrative element carrying copper resistance genes designated IECuR. Plasmid pNL6-2 (r3-T5; 15 Kbp) is a Rep_3/OrfX plasmid that includes a tet39 dif module, and pNL6-3 (r3-T20; 66.9 Kbp) carries aacC2d, aphA6, and blaCARB-16 and a second ampC gene preceded by an ISAba1. Conjugation of pNL6-3 into derivatives of ATCC17978 was demonstrated, confirming that the ampC gene confers resistance to third-generation cephalosporins. NL6 was compared to other complete ST10 genomes. Several acquired elements in the chromosome were shared with the ST10 isolate LAC-4 (USA), indicating shared ancestry, but the plasmid content differed. The KL and plasmid content were variable in 17 further complete ST10 genomes downloaded from GenBank. Tn6250 and IECuR were only found together in the chromosome of two further KL49 isolates. Antibiotic resistance in ST10 A. baumannii was acquired mainly via plasmid acquisition, but resistance genes varied, and a variety of plasmids was involved.IMPORTANCEMembers of the CC10 clonal complex of Acinetobacter baumannii comprising ST10 plus single and double locus variants are known to be particularly virulent. However, antibiotic resistance in members of this group has rarely been examined. Here, determination of the complete genome (chromosome and plasmids) of a representative ST10 isolate from Vietnam allowed the context and location of acquired antibiotic resistance genes and of other mobile genetic elements to be determined. Mobile genetic element locations in completed chromosomes facilitate comparisons of potentially related genomes, revealing those with recent shared ancestry. Differences in plasmid content can also be examined.

Acinetobacter baumannii↗

Next-Generation Sequencing Methods for Sensitive Hepatitis B Viral Genome Analysis: A European Study.

This multicentre study investigated the utility of next-generation sequencing (NGS) to detect and generate hepatitis B virus (HBV) genomes in samples of low viral load (from 0.2 to 6207 IU/mL). 23 HBV DNA-positive plasma samples of genotypes A-E and one HBV-negative control sample were assayed blindly via 9 established NGS methods from 6 European laboratories. Methods included untargeted metagenomics, pre-enrichment by probe-capture followed by Illumina sequencing, and HBV-specific PCR pre-amplification followed by sequencing with Nanopore or Illumina. Full HBV genomes were obtained only from samples with viral loads > 1000 IU/mL using probe-capture methods, > 200 IU/mL using PCR-Illumina methods, > 10 IU/mL using PCR-Nanopore methods, and in no samples using metagenomic methods. Contamination was observed in the negative control and samples with very low viral loads in PCR-based methods. Probe-capture and metagenomic methods detected additional viruses not routinely screened in blood donations, including polyomaviruses and herpesviruses; positive results were confirmed by PCR. In conclusion, NGS may delineate whole-genome sequences at low viral loads if supported by a PCR pre-amplification step. Probe-capture methods also reliably detect HBV without pre-amplification but show limited genome coverage for samples with low viral loads; they may additionally detect a wide range of blood-borne viruses.

Humans↗

Genomic signatures of cold adaptation in a Himalayan drosophilid.

Drosophila nepalensis is a cold-adapted drosophilid endemic to the Himalayan region. Its ability to survive in harsh, cold conditions makes it a valuable Drosophila model for investigating how adaptation to thermal extremes may influence species persistence under future climate change. Here, we report the first de novo genome assembly of D. nepalensis, based on a hybrid sequencing strategy that combines Illumina short reads and Oxford Nanopore long reads. Illumina sequencing generated 49.88 million 150 bp paired-end reads (∼14.96 Gbp), while Nanopore sequencing produced 1.35 million long reads totaling ∼0.76 Gbp. The assembled genome spanned ∼178 Mb with an N50 of 83.6 kb and 98% BUSCO completeness, comparable to other well-annotated Drosophila genomes. Annotation identified 10,560 protein-coding genes, including transcription factor-rich and stress-related domains such as zinc fingers, WD40 repeats, and ankyrin motifs. Comparative orthology analysis across 6 Drosophila species identified 14,168 orthologous clusters, of which 9,173 were shared among all 6 species, indicating a conserved core genomic set across the sampled taxa. D. nepalensis showed 83 unique orthogroups and 50 singletons, suggesting some lineage-specific gene expansions associated with cold adaptation and endemicity, including families encoding caspase-family apoptotic regulators, chromatin remodeling proteins (HMGB/protamine-like), and SNARE-domain vesicle trafficking factors. Gene family evolution analysis revealed the highest expansions in the cold-tolerant Himalayan drosophilid, D. nepalensis, including significant expansions in serine protease, chaperone, and neurotransmitter transporter families, alongside dramatic contractions of core histone gene families, suggesting lineage-specific chromatin remodeling and ecological specialization.

Drosophila nepalensis↗

Deciphering mixed infections by plant RNA virus and reconstructing complete genomes simultaneously present within-host.

Local co-circulation of multiple phylogenetic lineages is particularly likely for rapidly evolving pathogens in the current context of globalisation. When different phylogenetic lineages co-occur in the same fields, they may be simultaneously present in the same host plant (i.e. mixed infection), with potentially important consequences for disease outcome. This is the case in Burkina Faso for the rice yellow mottle virus (RYMV), which is endemic to Africa and a major constraint on rice production. We aimed to decipher the distinct RYMV isolates that simultaneously infect a single rice plant and to sequence their genomes. To this end, we tested different sequencing strategies, and we finally combined direct cDNA ONT (Oxford Nanopore Technology) sequencing with the bioinformatics tool RVhaplo. This method was validated by the successful reconstruction of two viral genomes that were less than a hundred nucleotides apart (out of a genome of 4450nt length, i.e. 2-3%), and present in artificial mixes at a ratio of up to a 99/1. We then used this method to subsequently analyze mixed infections from field samples, revealing up to three RYMV isolates within one single rice plant sample from Burkina Faso. In most cases, the complete genome sequences were obtained, which is particularly important for a better estimation of viral diversity and the detection of recombination events. The method described thus allows to identify various haplotypes of RYMV simultaneously infecting a single rice plant, obtaining their full-length sequences, as well as a rough estimate of relative frequencies within the sample. It is efficient, cost-effective, as well as portable, so that it could further be implemented where RYMV is endemic. Prospects include unravelling mixed infections with other RNA viruses that threaten crop production worldwide.

Genome, Viral↗

Nanopore-based, long-range Parvovirus B19 amplicon sequencing for near-whole genome characterization.

BACKGROUND: Whole-Genome Sequencing (WGS) enables monitoring of genomic variation and evaluation of diagnostic PCR assays. However, WGS data for Parvovirus B19 (B19V) remains limited despite its relevance for clinical care and transfusion safety. To increase the availability of high-quality B19V genomic data, a near-WGS protocol was developed and validated. METHOD: The protocol combines long-range PCR to generate a 4.6-kb amplicon, covering ∼82% of the B19V genome, with Oxford Nanopore sequencing. Validation was performed using six reference samples and nineteen B19V-positive donor plasma samples. RESULTS: After quality control, samples achieved a median sequencing depth of 152x. Sequences generated from the six reference samples showed 100% concordance with previously published data. Genomic analysis of donor samples explained atypical amplification profiles observed during routine PCR screening. CONCLUSION: The newly developed protocol provides a scalable method for B19V genome characterization, enabling assessment of oligonucleotide-binding regions for PCR assay monitoring and facilitating the generation of genomic data for future epidemiological investigations.

PCR assay monitoring↗

ONT-only genome assembly of a Korean male individual using a semen sample.

BACKGROUND: Long-read sequencing has enabled the generation of high-quality human genome assemblies, but many previous assemblies were based on blood-derived DNA and often relied on limited data types from a single sequencing strategy. OBJECTIVE: This study aimed to generate high-quality phased genome assemblies of a Korean individual using multiple independent long-read datasets produced from a single sequencing platform and to evaluate their utility for chromosome-scale assembly and variant detection. METHODS: Genomic DNA was extracted from a semen sample of a Korean male. Long-read, ultra-long-read, and chromatin conformation capture sequencing data were generated using Oxford Nanopore Technologies. These datasets were integrated to construct phased genome assemblies, followed by correction of noticeable phasing errors and assessment of assembly continuity, chromosomal representation, telomeric repeat recovery, and variant detection performance. RESULTS: The final phased assemblies spanned approximately 2.9 Gb and represented 23 pairs of chromosomes with an NG50 of 150 Mb. Telomeric repeats were detected at 36 and 37 of the 48 chromosomal ends in the two assemblies, indicating high end-to-end completeness. In addition, we successfully identified structural variants, including small variants. These results demonstrate that combining multiple Oxford Nanopore data types can produce highly continuous and informative phased human genome assemblies. CONCLUSIONS: We generated high-quality phased genome assemblies of a Korean individual using Oxford Nanopore long-read sequencing data derived from semen DNA. This publicly available genome resource will support broader applications of long-read sequencing in human genomics and variant analysis.

Humans↗