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Chromosome-level genome assembly and annotation of Pterygoplichthys pardalis.

Suckermouth catfishes, with their evolved powerful features, have become notorious invasive species, causing significant damage to aquatic ecosystems. However, the lack of high-quality genomes severely restricts research on this group within the field. In this study, we de novo assembled the chromosome-level genome assembly of Pterygoplichthys pardalis using multiple platforms of sequencing data, including Illumina short reads, Nanopore long reads, and Hi-C sequencing reads, resulting in a 1.51 Gb genome assembly. Multiple evaluations, including read mapping ratio (98.52%), transcript mapping ratio (99.61%), conserved BUSCO gene set (98.8%), and N50 score (49.47 Mb), indicated the high continuity and accuracy of the genome assembly we generated. Genome annotation found that 0.97 Gb of genome sequences are repetitive sequences, accounting for 64.47% of the genome assembly. Further, 23,859 protein-coding genes were successfully predicted, 92.92% of which could be annotated in functional databases. This high-quality genome assembly of P. pardalis provides a valuable resource for understanding the genetic underpinnings of P. pardalis's invasive success and offers critical data for future fisheries research and management.

Animals↗

A De Novo 16p13.3 Triplication Underlying Early-Onset Complex Neurodegeneration.

BACKGROUND: Neurodegenerative disorders are clinically and genetically heterogeneous, characterized by progressive neuronal loss and multidomain functional decline. Despite a presumed genetic etiology, a substantial proportion of cases remain molecularly undiagnosed. OBJECTIVE: The aim was to identify the genetic cause of an early-onset neurodegenerative disorder presenting with ataxia and cognitive impairment. METHODS: Rare copy-number variants were detected via short-read whole-genome sequencing (WGS), with candidate structural models inferred using long-read WGS. We performed transcriptomic profiling of peripheral blood leukocytes by RNA sequencing, with validation using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RESULTS: We identified a de novo copy-number gain at 16p13.3. Combined copy-number profiling and long-read WGS suggested a candidate model comprising a triplicated segment in tandem with a proximal duplication, joined to a distal duplication via an inverted junction. Transcriptomic analysis demonstrated significant upregulation of ATP6V0C, AMDHD2, and PDPK1. CONCLUSIONS: These findings support a role for structural variation in early-onset neurodegeneration and highlight the value of combining short-read copy-number profiling with long-read WGS to detect and characterize complex genomic rearrangements. © 2026 International Parkinson and Movement Disorder Society.

16p13.3↗

Intron within the large rRNA gene of N. crassa mitochondria: a long open reading frame and a consensus sequence possibly important in splicing.

We describe the sequence of the 2295 nucleotide long intron and 245 nucleotides of the flanking exon sequences within the large (24S) rRNA gene of Neurospora crassa mitochondria. The intron contains a long open reading frame, which could correspond to ribosomal protein S5. Comparison with the corresponding intron of the large rRNA gene of yeast mitochondria reveals a single highly homologous 57 nucleotide long sequence, including the sequence (formula; see text), which is present in virtually all the sequenced introns of yeast, Aspergillus nidulans and Zea mays mitochondrial genes, and which may be important for their processing. Sequences closely related to this consensus sequence are also present within all four of the introns of nuclear rRNA genes which have been sequenced. The intron is located within a highly conserved region of the large rRNA sequence and at exactly the same site as in the corresponding introns in yeast mitochondria and also in Physarum polycephalum nuclei.

Base Sequence↗

Beyond Canonical Neoantigens: Emerging Technologies for Identification of Noncanonical Antigens and Implications for Personalized Cancer Vaccines.

Over the past decade, advances in sequencing technologies and computational pipelines enabled the development of personalized cancer vaccines (PCVs). Current PCV strategies primarily target cancer neoantigens generated by non-synonymous DNA mutations, which can result in altered amino acid sequences capable of eliciting tumor-specific immune responses. More recently, a distinct class of tumor-specific antigens (TSA), termed noncanonical or cryptic antigens, has emerged as an additional source of immunogenic targets. Unlike canonical neoantigens, noncanonical antigens typically cannot be identified by tumor/normal whole-exome sequencing, as they do not arise from classical DNA mutations. Instead, they are often associated with less well recognized and/or aberrant processes in the pathways from DNA to human leukocyte antigen (HLA)-presented peptides. Examples include transposable elements, circular RNA, translation of alternative open reading frames and/or long non-coding RNA, among others. Emerging evidence suggests that noncanonical antigens represent a substantial portion of the tumor-specific immunopeptidome and, similar to canonical neoantigens, are absent during thymic selection and can evade central tolerance and elicit T cell responses. Technological advances have increasingly facilitated the identification of noncanonical antigens. Long-read RNA sequencing reveals noncanonical transcripts by improving transcriptome assembly, while ribosome profiling provides genome-wide maps of actively translated regions, facilitating the discovery of peptides from aberrant translation events. Specialized molecular approaches enable enrichment and sequencing of circular RNAs, and immunopeptidomics using mass spectrometry allows for direct characterization of HLA-presented peptides. Together, these technological advances have led to an increasing interest in prioritizing and targeting noncanonical antigens in the next generation of PCVs. This review provides an overview of the diverse origins of TSAs beyond classical neoantigens and discusses emerging approaches that may enable the integration of these antigens in future clinical trials.

circular RNA↗

Development and evaluation of a multiplex PCR-based dual-platform targeted sequencing framework for precise differentiation of lumpy skin disease virus.

BACKGROUND: Lumpy skin disease virus (LSDV) shares over 96% genomic identity with goatpox and sheeppox viruses, presenting severe diagnostic challenges due to cross-reactivity. METHODS: To address this bottleneck, we established a targeted sequencing framework integrating multiplex PCR with short-read and long-read platforms. By sequentially screening target pathogens, identifying low-homology genes, and designing short and gradient long-fragment primer pools, we evaluated these dual-platform panels using highly homologous poxvirus samples. RESULTS: The short-read panel stably detected target viruses at inputs as low as 5.26 ×101 copies/μL. Under strict alignment criteria, LSDV mapping rates reached 42.91%, suppressing non-target signals to 3.05%. The Nanopore-Targeted Sequencing (NTS) long-amplicon strategy successfully eliminated homologous interference. By applying length-dependent diagnostic thresholds (≥ 100 reads for short amplicons; ≥ 50 reads for long amplicons), precise species-level identification was achieved, maintaining near-zero cross-reads (0-5) in ultra-long regions. Crucially, the field-deployable NTS workflow enabled complete detection in approximately 4 h. CONCLUSION: This complementary strategy seamlessly meets both laboratory demands for high-sensitivity enrichment and frontline requirements for rapid typing, providing a reliable tool for LSDV surveillance, mutation tracking, and outbreak control.

Capripoxvirus differentiation↗

A large interspersed repeat found in mouse DNA contains a long open reading frame that evolves as if it encodes a protein.

DNA sequence analysis of a region contained within a large, interspersed repetitive family of mice reveals a long open reading frame. This sequence extends 978 base pairs between two stop codons, creating a reading frame that is open for 326 amino acids. The DNA sequence in this region is conserved between three distantly related Mus species, as well as between mouse and monkey, in a manner that is characteristic of regions undergoing selection for protein function.

Amino Acid Sequence↗

Decipher RNA isoform combinations from minigene splicing assays and massive parallel sequencing with MAGIC.

SUMMARY: Functional testing of RNA using minigene splicing assays is increasingly being realized to demonstrate the effects of variants on splicing. In complex cases, variant pathogenicity is assessed by Sanger sequencing, which can be time consuming and may be replaced by short read sequencing. Moreover, strategies based on long read sequencing of the amplified minigene construct are promising and allow the isoforms to be fully characterized. We introduce MAGIC, a user-friendly tool that first generates the artificial construction genome files required to then perform alignment, assembly and annotation of the isoforms obtained by either short or long read minigene splicing assay sequencing. AVAILABILITY AND IMPLEMENTATION: MAGIC is available at https://github.com/LBGC-CFB/MAGIC. Zenodo DOI: 10.5281/zenodo.17052752.

High-Throughput Nucleotide Sequencing↗

A personalized multi-platform assessment of somatic mosaicism in the human frontal cortex.

Somatic mutations in individual cells create genomic mosaicism, influencing genetic disorders and cancers. While clonal mutations in cancers are well-studied, rarer somatic variants in normal tissues remain poorly characterized. This study systematically evaluates detection methods using a personalized donor-specific assembly (DSA) from a neurotypical individual's dorsolateral prefrontal cortex assessed with Oxford Nanopore, NovaSeq, linked-read sequencing, Cas9-targeted long-read sequencing (TEnCATS), and single-neuron MALBAC amplification. The haplotype-resolved DSA improved cross-platform analysis, dramatically increasing phasing rates. Germline SNVs, structural variations (SVs), and transposable elements (TEs) were recalled with 99.4%-99.7% accuracy in bulk tissue, and phased haplotype analysis reduced false positives by 15.4%-75.1% for putative somatic candidates. Long-read single-neuron sequencing detected nine somatic SV candidates, demonstrating enhanced sensitivity for rare variants, while TEnCATS identified eight low-frequency somatic TE candidates. These findings highlight advanced methodologies for precise somatic variant detection, critical for understanding mosaicism's role in health and disease.

Multi-platform Sequencing↗

The mitochondrial plasmid from Neurospora intermedia strain Labelle-1b contains a long open reading frame with blocks of amino acids characteristic of reverse transcriptases and related proteins.

We have determined the DNA sequence of the 4070 base pair mitochondrial plasmid from the Labelle-1b strain of Neurospora intermedia. Analysis of the sequence revealed that the plasmid contains a long open reading frame (ORF) that could encode a protein of up to 1151 amino acids. Codon usage in the long ORF shows no clear relationship to Neurospora mitochondrial genes, nuclear genes, nor to the ORF of a different Neurospora mitochondrial plasmid. The long ORF contains regions of similarity to yeast mitochondrial RNA polymerase as well as blocks of amino acids that are characteristic of reverse transcriptases and the ORFs of certain group II mtDNA introns (Michel and Lang, (1985) Nature 316,641). The plasmid gives rise to specific transcripts, some of which may be unit length, and which carry the information for expression of the long ORF. The genetic organization and content of the plasmid suggest that it is related to mobile genetic elements.

Amino Acid Sequence↗

The developmentally regulated type X collagen gene contains a long open reading frame without introns.

Type X collagen is a recently discovered product of hypertrophic chondrocytes that is localized to presumptive mineralization zones of hyaline cartilage. Thus, in the epiphyseal growth plate of long bones it is present only in the zone of hypertrophic chondrocytes and absent in the resting and rapidly growing cartilage and in bone. Type X collagen represents, therefore, a transient and developmentally regulated collagen which is synthesized by a subpopulation of chondrocytes. We report here the isolation and characterization of cDNA and genomic clones specific for the chicken protein. The results demonstrate that the polypeptide chains of this collagen contain three distinct domains: a short non-collagenous, amino-terminal region, a collagenous domain of 460 amino acid residues, and a non-collagenous, carboxyl-terminal domain of 170 amino acid residues. The nucleotide sequence of the gene shows that these domains are encoded by a long open reading frame that is not interrupted by introns. Examination of the amino acid sequence derived from this nucleotide sequence reveals the presence of a hydrophobic segment localized 10 amino acid residues upstream from the translational stop codon. The length and sequence characteristics of this segment raise the intriguing possibility that Type X collagen polypeptides may contain a transmembrane segment.

Amino Acid Sequence↗

The complete sequence of the unit YCR59, situated between CRY1 and MAT, reveals two long open reading frames, which cover 91% of the 10.1 kb segment.

We have entirely sequenced YCR59, which is a 10.1 kb segment of the right arm of chromosome III, and is part of the clone E5F from the Newlon collection. The segment contains two long open reading frames (ORFs): YCR591 which starts in the adjacent fragment H9G (situated towards CRY1 and the centromere), and continues with 1833 codons in YCR59. The second ORFYCR592 is 1226 codons long and encoded entirely within YCR59. The two ORFs represent 91% of the total length of the segment. Excellent agreement in both location and length is found between the ORFs YCR591 and YCR592 and the transcripts 86 and 87 respectively in the Yoshikawa and Isono (1990) map of chromosome III. The two ORFs correspond to new genes and show no significant similarity with any known genes.

Amino Acid Sequence↗

Subcellular localization of the product of the long open reading frame of human T-cell leukemia virus type I.

Human T-cell leukemia virus type I (HTLV-I) is a retrovirus associated with adult T-cell leukemia and lymphoma. In addition to containing the gag, pol, and env genes of the chronic leukemia viruses, the genome of HTLV-I contains a long open reading frame (LOR) located between the 3' end of the envelope gene and the 3' long terminal repeat sequence (LTR). It has been suggested that a protein of 42 kilodaltons that is encoded by the LOR region may participate in both trans-acting transcriptional regulation of the viral LTR as well as in the transforming properties of HTLV-I. It is reported here that a significant fraction of the 42-kilodalton HTLV LOR product is located in the nucleus of HTLV-I-infected transformed lymphocytes, a finding that is consistent with its proposed functions.

Cell Fractionation↗

Patterns of Drug Resistance, Drug Resistance Conferring Mutations and Genomic DNA Methylation Revealed in Mycobacterium tuberculosis From South Africa.

Tuberculosis remains a major public health threat globally, with drug-resistant strains undermining treatment efficacy. We analyzed 126 Mycobacterium tuberculosis (M. tuberculosis) isolates with diverse drug resistance spectra and selected 35 for whole genome sequencing (WGS) using Illumina NextSeq, SMRT PacBio Onso and SMRT PacBio Revio sequencing platforms. The study aimed to characterize drug resistance profiles, compare short- and long-read sequencing performance, identify lineages among South African isolates, detect known drug resistance mutations and their lineage-specific patterns, and utilize long-read SMRT platforms for epigenetic profiling. Multiple drug resistance mutations were identified, some lineage-specific, and notably, East-African-Indian (EAI) Lineage 1 isolates often considered less pathogenic, showed significant potential for multidrug-resistance development, including higher fluoroquinolone resistance as compared to other lineages. Three DNA motifs with methylated adenines, namely CACGCaG, CtCCaG and GaTNNNNRtAC, were detected, with methylation patterns varying by lineage and strain due to mutations in the corresponding methyltransferases (MTases). A particularly notable finding was the stable maintenance of a genetic heterogeneity in the mamB MTase, performing methylation at CACGCaG motifs. These results highlight the combined role of genetic and epigenetic variation in M. tuberculosis adaptive evolution and underscore the value of integrating long-read sequencing into TB surveillance and research.

Mycobacterium tuberculosis↗

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↗

Replication and packaging of coronavirus infectious bronchitis virus defective RNAs lacking a long open reading frame.

The construction of a full-length clone of the avian coronavirus infectious bronchitis virus (IBV) defective RNA (D-RNA), CD-91 (9,080 nucleotides [Z. Penzes et al., Virology 203:286-293]), downstream of the bacteriophage T7 promoter is described. Electroporation of in vitro T7-transcribed CD-91 RNA into IBV helper virus-infected primary chick kidney cells resulted in the production of CD-91 RNA as a replicating D-RNA in subsequent passages. Three CD-91 deletion mutants were constructed--CD-44, CD-58, and CD-61--in which 4,639, 3,236, and 2,953 nucleotides, respectively, were removed from CD-91, resulting in the truncation of the CD-91 long open reading frame (ORF) from 6,465 to 1,311, 1,263, or 2,997 nucleotides in CD-44, CD-58, or CD-61, respectively. Electroporation of in vitro T7-transcribed RNA from the three constructs into IBV helper virus-infected cells resulted in the replication and packaging of CD-58 and CD-61 but not CD-44 RNA. The ORF of CD-61 was further truncated by the insertion of stop codons into the CD-61 sequence by PCR mutagenesis, resulting in constructs CD-61T11 (ORF: nucleotides 996 to 1,058, encoding 20 amino acids), CD-61T22 (ORF: nucleotides 996 to 2,294, encoding 432 amino acids), and CD-61T24 (ORF: nucleotides 996 to 2,450, encoding 484 amino acids), all of which were replicated and packaged to the same levels as observed for either CD-61 or CD-91. Analysis of the D-RNAs showed that the CD-91- or CD-61-specific long ORFs had not been restored. Our data indicate that IBV D-RNAs based on the natural D-RNA, CD-91, do not require a long ORF for efficient replication. In addition, a 1.4-kb sequence, corresponding to IBV sequence at the 5' end of the 1b gene, may be involved in the packaging of IBV D-RNAs or form part of a cis-acting replication element.

Animals↗

Identification and characterization of an L1 family sequence with a very long open reading frame in the third intron of the human thymidylate synthase gene.

A long L1 repetitive sequence (3.6 kilobase pairs) was found in the third intron of the human thymidylate synthase gene. This L1 family sequence is unique in that it possesses the longest open reading frame (1.7 kilobase pairs) of all L1 family members identified in sequences associated with specific genes that have been cloned thus far. Furthermore, the amino acid sequence deduced from the open reading frame of the L1 sequence was found to be highly homologous (90%) to that encoded by a known human teratocarcinoma L1 RNA species, and to contain several blocks of sequences homologous to ones in RNA-dependent DNA polymerases of various origins.

Amino Acid Sequence↗

Comparative evaluation of three high-molecular-weight DNA extraction kits for Oxford Nanopore sequencing of Clostridioides difficile and Clostridium perfringens.

UNLABELLED: Clostridioides difficile and Clostridium perfringens are Gram-positive, spore-forming anaerobic pathogens affecting humans and animals, for which genomic data have been mainly generated using short-read or hybrid sequencing approaches. In this study, we evaluated three commercial non-bead-beating DNA extraction kits designed for high-molecular-weight DNA recovery for Oxford Nanopore long-read whole-genome sequencing of two C. difficile and two C. perfringens strains, including one reference strain and one clinical or environmental isolate per species. Based on sequencing performance and kit ease of use, one kit was selected for additional sequencing of plasmid-carrying strains of both species. All three kits allowed correct identification of sequence types, toxin-encoding genes, and antimicrobial resistance determinants, confirming their suitability for clinical and epidemiological applications. However, the BT MasterPure Kit provided the highest DNA concentrations, longest fragment sizes, and superior read lengths and N50 values, particularly for C. difficile, achieving >100× coverage and enabling reliable circularization of chromosomes and plasmids, including a C. difficile metronidazole resistance plasmid and C. perfringens plasmids carrying toxin and antibiotic resistance genes. The other kits produced slightly lower DNA yields, resulting in shorter reads and reduced genome coverage for C. difficile, highlighting the challenge of extracting high-quality DNA from Gram-positive, spore-forming bacteria. Overall, this study provides practical guidance for selecting DNA extraction protocols optimized for Oxford Nanopore sequencing of C. difficile and C. perfringens, supporting high-quality genome assemblies and plasmid characterization and facilitating the routine genomic surveillance of clinically relevant spore-forming pathogens. IMPORTANCE: High-quality genomic data are essential for accurate characterization of Clostridioides difficile and Clostridium perfringens, two clinically and epidemiologically important Gram-positive, spore-forming pathogens. However, long-read sequencing performance can be strongly influenced by the choice of DNA extraction method, particularly for organisms with robust cell walls, where commonly used methods can lead to fragmented DNA. In this work, DNA of four strains was extracted using three commercial high-molecular-weight DNA extraction kits and sequenced using Oxford Nanopore Technologies. The best-performing kit was also evaluated using three additional strains known to harbor plasmids in order to assess its plasmid recovery efficiency. The results demonstrated successful plasmid recovery, circularization, and characterization. DNA extraction protocols optimized for Oxford Nanopore sequencing enable the rapid and cost-effective characterization of C. difficile and C. perfringens for genomic surveillance or outbreak investigations.

Clostridioides difficile↗