PubMed HealthSearch

SEARCH · PubMed Health

Results for “chromosome-scale genome”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources

Chromosome-scale genome assembly and genomic prediction of essential oil compounds in Atractylodes lancea for genomics-assisted breeding.

Atractylodes lancea rhizomes are used as crude drugs. Essential oil compounds, including atractylodin, hinesol, β-eudesmol, and atractylon, are key determinants of crude drug quality. Conventional breeding of A. lancea is difficult because of its perennial growth. In this study, a chromosome-scale reference genome of A. lancea (4.79 Gb) was generated, and genome-wide association studies (GWAS) and genomic predictions of essential oil compounds were conducted to explore the potential for genome-assisted breeding. Genotyping of 480 lines using double-digest restriction-site-associated DNA-sequencing yielded 29,136 high-quality SNPs. All the compounds showed high genomic heritability (h2 = 0.758-0.915), indicating strong genetic control. Despite the high genomic heritability, GWAS detected only one weak association with atractylon and no significant loci for the three compounds. However, genomic prediction achieved moderate to high accuracy across multiple models, particularly the ridge regression, genomic best linear unbiased prediction, and Bayesian approaches. The prediction accuracy, measured as the Pearson correlation coefficient between the observed and predicted values, exceeded 0.6 for all four essential oil compounds. These results demonstrate the efficacy of genomic selection for improving essential oil compound levels in A. lancea and provide a foundation for genome-assisted breeding of medicinal plants with long breeding cycles.

Atractylodes lancea

Characterization of a draft chromosome-scale genome assembly for the mutton snapper, Lutjanus analis.

BACKGROUND: The mutton snapper (Lutjanus analis) is a reef fish commonly found in tropical waters of the Western Atlantic Ocean. Genomic studies of this species are needed to support conservation efforts and breeding programs. OBJECTIVE: Here, we report the development of a chromosome-scale reference assembly for the mutton snapper and conduct an initial comparative genomic analysis with other lutjanids. METHODS: The genome of one mutton snapper specimen was sequenced using PAC-Bio HiFi long reads and Illumina short reads. Contigs and scaffolds were assembled in the Flye pipeline and anchored using Hi-C proximity guided assembly. Gene prediction and functional annotations were obtained in AUGUSTUS and eggNOG-mapper, respectively. The mutton snapper genome was compared to those of other lutjanids to infer gene family evolution and chromosome synteny conservation. RESULTS: Assembly and polishing yielded 946 contigs and 926 scaffolds (N50 of 3.16 Mb, complete BUSCO score 98.1%) that were anchored using Hi-C scaffolding in 24 draft chromosomes. The anchored assembly featured a N50 of 42.47 Mb and contained 97.6% of the unanchored assembly length. The 24 mutton snapper chromosomes showed a one-to-one syntenic relationship with their counterparts in medaka, and other Lutjanids. AUGUSTUS predicted 29,023 genes, 24,335 of which (83.85%) could be functionally annotated. Gene family evolution analysis revealed 1,014 significantly expanded or contracted hierarchical ortholog groups in mutton snapper. Expansions and contractions were linked to several biological functions including growth, oocyte maturation, and response to exogenous stressors. CONCLUSION: The draft genome will be a valuable tool for forthcoming applied genomic studies of mutton snapper.

Animals

A gap-free, telomere-to-telomere chromosome-scale genome assembly of the mangrove red snapper, Lutjanus argentimaculatus.

The mangrove red snapper (Lutjanus argentimaculatus) is a commercially important marine fish species in the Indo-Pacific region. Despite its significant economic value for aquaculture, existing genomic resources remain fragmented, limiting the advancement of molecular breeding and functional genomic studies. Here, we present a gap-free, telomere-to-telomere (T2T) genome assembly of L. argentimaculatus, generated using a hybrid approach combining PacBio HiFi, Oxford Nanopore ultra-long reads and Hi-C technology. The resulting assembly comprises exactly 24 scaffolds spanning 1.03 Gb, perfectly matching the haploid chromosome number with a contig N50 of 46.17 Mb. Notably, this assembly resolves all physical gaps present in previous versions, achieving a BUSCO completeness score of 98.2%. Comprehensive genome annotation successfully predicted 23,167 protein-coding genes. Among these, 22,067 genes (95.25%) were functionally annotated across major public databases, including eggNOG, InterPro, and Swiss-Prot. Furthermore, structural analysis successfully identified 19 telomeres and 20 centromeres, validating the chromosomal integrity. This high-fidelity, gap-free reference genome provides a robust foundation for comparative genomics, population genetics, and the genetic improvement of Lutjanidae species.

Animals

ntSynt-viz: Visualizing synteny patterns across multiple genomes.

With the explosion of chromosome-scale genome assemblies being generated in recent years, there is vast potential for comparative genomics analyses through detecting multi-genome synteny. While existing tools can detect synteny blocks between multiple genomes, their text-based outputs make it challenging to intuitively explore large-scale synteny patterns. Interpretable, information-rich and easy-to-use synteny visualization tools are imperative to enable important biological insights from the synteny block data output by the aforementioned utilities. Here, we present ntSynt-viz, a command-line tool for automated sorting, normalization and plotting of multi-genome synteny blocks. We show how ntSynt-viz provides clearer and more easily interpretable chromosome painting ribbon plots compared to the state-of-the-art tools NGenomeSyn and plotsr when evaluating synteny between 14 human genomes, and compared to NGenomeSyn when comparing 9 hoverfly genomes. As plotsr is limited to comparing genomes with equal chromosome numbers, it was not applicable to the hoverfly dataset. Furthermore, we demonstrate how ntSynt-viz can also be applied to visualize syntenic patterns encoded in pangenome graphs, using a Minigraph-Cactus graph built from 16 Drosophila genomes. We expect that ntSynt-viz will provide crucial insights into large-scale synteny patterns between divergent genomes, thereby advancing research into key evolutionary questions.

Synteny

Chromosome-level genome assembly and annotation of the porcupine fish (Diodon hystrix).

The porcupinefish (Diodon hystrix), a coral reef teleost, is widely distributed in tropical/subtropical waters of the Pacific, Atlantic, Indian Oceans, and Mediterranean Sea. It shares easily recognizable features with pufferfish, such as body inflation and spines. Additionally, its culinary value makes D. hystrix a highly desirable species in many tropical coastal regions, with considerable market potential. However, lack of a high-quality genome hindered further studies on its reproduction, molecular biology, and genomic improvement. Here, we assembled the chromosome-scale genome using PacBio HiFi, ultra-long reads, and Hi-C. Of the 713.62 Mb genome, 98.63% anchored to 23 chromosomes (scaffold N50: 31.52 Mb) with 39.82% repetitive sequences. The assembled genome achieved a BUSCO completeness score of 97.7%, with 23,171 protein-coding genes predicted, 22,221 of which were functionally annotated. Phylogenetic analysis identified D. hystrix's evolutionary relationships with other species in the Tetraodontiformes. In summary, the high-quality genome of D. hystrix sheds light on valuable insights into genome size evolution, and provides a valuable resource for exploiting genomic study and breeding applications in this species.

Animals

CHITRA: an interactive visualization tool for comparative genomic rearrangement analysis.

MOTIVATION: The increasing availability of chromosome-scale genome assemblies has fuelled a renewed interest in studying chromosomal evolution and rearrangements. Synteny visualization plays a critical role in understanding genome organization, structural variations, and evolutionary relationships. However, existing tools often have steep learning curves, produce static plots, or are limited in their ability to analyse multiple genomes simultaneously. There is a growing need for an intuitive and interactive visualization tool that can effectively explore syntenic relationships and chromosomal rearrangements. RESULTS: Here, we present CHITRA, a web-based interactive tool designed to visualize synteny blocks, chromosomal rearrangements, and breakpoints in both linear and circular styles. CHITRA-enables real-time exploration of genome structural variations with an intuitive graphical interface, customizable visualization options, and high-resolution export capabilities for publication-ready figures. The tool supports chromosome- and scaffold-level assemblies and allows users to filter, highlight, and interactively examine syntenic relationships. AVAILABILITY AND IMPLEMENTATION: CHITRA is freely available at https://chitra.bioinformaticsonline.com/, with comprehensive documentation at https://chitra.bioinformaticsonline.com/docs. The source code is open-source and accessible on GitHub at https://github.com/pranjalpruthi/CHITRA.

Journal Article

SynFlow: an interactive online genome structural variant viewer.

MOTIVATION: Structural variations (SVs), including inversions, translocations (TRAs), duplications, and large insertions or deletions, are key drivers of genome evolution and phenotypic diversity. With the increasing number of high-quality, chromosome-scale genome assemblies, the ability to detect and interpret SVs has become a crucial aspect of modern genomics. While SV detection has advanced, most visualization methods produce static plots that fall short when researchers, particularly in comparative genomics, need to interactively explore large datasets, zoom into specific genomic regions, or dynamically filter structural events in real time. RESULTS: To address this gap, we introduce SynFlow, a lightweight, web-based interactive application specifically designed for exploring and visualizing SVs identified by SyRI. We demonstrate that SynFlow can reproduce complex static synteny plots published in literature, but transforms them into dynamic, shareable visualizations that support real-time filtering, reordering, and deep exploration of specific SVs, including TRAs. SynFlow is available as a web server and offers multiple entry points: browsing precomputed datasets (e.g. banana and grapevine genomes), uploading user-provided SyRI outputs, or running an integrated workflow to produce and visualize SVs on the fly. AVAILABILITY AND IMPLEMENTATION: https://synflow.southgreen.fr; source code https://github.com/SouthGreenPlatform/synflow; preprocessing Snakemake workflow https://gitlab.cirad.fr/agap/cluster/snakemake/synflow.

Software

Chromosome-level genome assembly of Manglietia pachyphylla.

Manglietia pachyphylla, an endangered evergreen tree within the Magnoliaceae family, is renowned for its exceptional ornamental value in landscape horticulture. Despite its classification as a Category II nationally protected plant species in China, the genetic basis of its adaptive traits and conservation priorities remains poorly understood. To address this, we present the first chromosome-scale genome assembly of M. pachyphylla utilizing an integrated approach combining PacBio HiFi long-read and Hi-C chromosome conformation capture sequencing technologies. The assembled genome spans 2.15 Gb (contig N50 = 43.57 Mb), exhibiting a heterozygosity rate of 0.78% and repeat content of 78.64%, predominantly comprising long terminal repeat (LTR) retrotransposons (52.86%). Hi-C scaffolding anchored 99.57% of the assembly to 19 pseudochromosomes, achieving a BUSCO completeness score of 96.4%. Annotation revealed 42,505 putative protein-coding genes, with 84.46% of predicted genes were functionally annotated. Phylogenomic analysis positioned M. pachyphylla and Oyama sieboldii clustered together in a well-supported group. This high-contiguity genome assembly enables future investigations into adaptive evolution, functional genomics, and evidence-based conservation strategies for this endangered species.

Chromosomes, Plant

Insights into dill (Anethum graveolens) flavor formation via integrative analysis of chromosomal-scale genome, metabolome and transcriptome.

INTRODUCTION: Dill (Anethum graveolens) is a significant medicinal herb belonging to the Apiaceae family. Owing to its high levels of volatile organic compounds (VOCs), dill is commonly utilized for essential oil extraction and medicine purpose. However, the biosynthesis of the crucial VOC in dill remains obscure. OBJECTIVES: Identify the key VOCs related to the flavor formation in dill and dissect the regulatory mechanism of their synthesis. METHODS: The dill chromosomal-level genome was constructed by PacBio HiFi, Hi-C, and BGISEQ second generation sequencing and assembly. The VOCs in dill leaves were identified through GC-MS. The potential mechanism involved in regulating the VOC accumulation in dill flavor formation was analyzed by multi-omics analysis. RESULTS: A 1.17 Gb chromosome-scale genome of dill with a contig N50 of 10.78 Mb was constructed. A total of 46,538 genes were annotated across 11 assembled chromosomes. Comparative genomics analysis suggested that transposable element insertions, especially LTR-Gypsy, have contributed to the evolution and expansion of the dill genome. The flavor formation of dill was mainly attributed to terpenoids, especially α-phellandrene, β-ocimene, and o-cymene. The contribution of expansion and replication of terpenoid synthesis pathway genes, especially terpene synthase (TPS), to the abundant terpenoid production of dill was identified. Differential gene expression patterns observed at various developmental stages and tissues provided key candidate genes for the regulation of terpenoid synthesis, as well as transcription factors. The different accumulation of esters and aromatics also affected the flavor formation of dill. The key genes implicated in the synthesis of anethole, namely AIS and AMT were further identified. CONCLUSION: This study constructed the chromosome level genome and identified the main VOCs and related key genes in flavor formation of dill, shedding lights on our understanding of terpenoid biosynthesis but also offered guidance for future genetic research on molecular breeding in Anethum graveolens.

Transcriptome

Chromosome-level genome assembly of the Vermilion Snapper (Rhomboplites aurorubens).

Vermilion Snapper (Rhomboplites aurorubens, Lutjanidae) inhabits deep waters (20-300 m) from North America to Brazil and supports significant commercial and recreational fisheries. Despite its economic importance, the understanding of its basic biology remains limited. Classified as Vulnerable on the Red List due to overfishing, populations have declined by over 30% in recent generations. We assembled and annotated the first chromosome-scale genome of this species by combining PacBio long reads, Illumina short reads, and Hi-C data. The resulting assembly is 987.5 Mbp, with a scaffold N50 size of 41.3 Mbp, and includes 135 contigs clustered and ordered onto 24 chromosomes with 34,496 predicted genes. The high-quality assembly and annotation contained about 98% complete and single-copy BUSCO genes. It is the most complete, chromosome-level genome assembly of an Atlantic snapper to date. The genome assembly and supporting data are valuable tools for ecological and comparative genomics studies of snappers and other valuable commercial species within the family.

Chromosomes

Genome-scale insights into metabolic streamlining and photosynthetic energy balance in the extremophile green alga Picocystis salinarum (Picocystophyceae, Chlorophyta).

Picocystis salinarum is an early-diverging chlorophyte and the sole described member of the Picocystophyceae, frequently dominating hypersaline and alkaline lakes despite extreme physicochemical constraints. To elucidate the genomic foundations of its ecological success, we generated a fully annotated, chromosome-scale nuclear genome assembly of the type strain originally isolated from a saline pond in San Francisco Bay. The 18.5-Mb genome comprises 30 chromosomal assemblies, exhibits clear diploidy, and contains multiple copies of intact Ty3/Gypsy and Ty1/Copia long terminal repeat retrotransposons encoding polyproteins with atypical accessory domains. Phylogenomic analyses reveal strong affinity with the Nephroselmidophyceae. Comparative analyses reveal extensive metabolic streamlining, including the absence of a queuosine salvage pathway, the 2-methylcitrate cycle, β-oxidation of propionate, and branched-chain amino acid catabolism, traits retained in several marine prasinophyte lineages. In contrast, the genome preserves multiple ancestral bacterial derived systems. Notably, P. salinarum features a complete chloroplast NADH dehydrogenase-like complex, including all membrane, electron binding, and assembly components, a configuration not previously reported in sequenced chlorophyte algae. This retention implies substantial capacity for cyclic electron flow and chlororespiration, processes expected to be critical in chronically low-light and chemically extreme environments. The genome further reveals a distinctive biochemical CO2-concentrating mechanism centered on plastid-targeted phosphoenolpyruvate carboxykinase, complete plastid peptidoglycan biosynthetic and remodeling pathways, and partial retention of lipid-A-related machinery. Conversely, P. salinarum lacks canonical non-photochemical quenching proteins while retaining xanthophyll-cycle enzymes that support slower photoprotective responses. Together, these features define a coordinated genomic architecture that underpins the specialization of P. salinarum to hypersaline, alkaline, and persistently low-light ecosystems.

3‐deoxy‐D‐manno‐octulo

Telomere-to-telomere genome of Phoebe chekiangensis reveals that age-dependent CHG hypomethylation promotes floral transition via MADS-box gene activation.

Phoebe species are renowned for their highly valuable 'golden thread' timber; however, their protracted juvenile phase presents a significant obstacle to mechanistic investigations of floral induction. Phoebe chekiangensis, a rare early-flowering representative within this genus, provides a unique model system for dissecting the vegetative-to-reproductive phase transition. Nevertheless, the absence of a high-quality reference genome has severely hindered molecular insights into its developmental regulation. Here, we present the first telomere-to-telomere (T2T) genome assembly for P. chekiangensis, comprising two completely gap-free haplotypes with contig N50 values exceeding 65 Mb, base-level quality scores >36, and Long Terminal Repeat Assembly Index scores surpassing the gold standard threshold of 20. Approximately 29 000 genes were annotated per haplotype, supported by a BUSCO completeness score of >97%. Age-resolved transcriptomic landscapes identified two MADS-box transcription factors, PcMADS5 (AP1-like) and PcMADS19.1 (SOC1-like), as core activators of the floral transition. Both genes triggered precocious flowering when ectopically expressed in Arabidopsis thaliana. Whole-genome bisulfite sequencing revealed a progressive, age-dependent decline in CHG (where H is A, C, or T) DNA methylation, which was particularly pronounced at the PcMADS19.1 locus. Notably, DML1/2, which mediate active DNA demethylation, were coordinately upregulated during the onset of reproductive growth. Chemical demethylation using 5-azacytidine further diminished CHG methylation and selectively enhanced PcMADS19.1 expression, confirming a causal relationship between CHG hypomethylation and transcriptional activation. This work delivers the first chromosome-scale T2T genome within the genus Phoebe and uncovers CHG demethylation as a previously unrecognized epigenetic switch governing reproductive competence in woody perennials.

Journal Article

Mining the sHSP20 (small heat-shock protein) gene family in finger millet (Eleusine coracana (L.) Gaertn.): structural, evolutionary and predicted abiotic-stress-responsive insights.

Small heat-shock proteins (sHSPs, the HSP20 family) are ATP-independent molecular chaperones that hold partially unfolded substrates and protect the proteome during heat and other abiotic stresses; every member is defined by a conserved &#x3b1;-crystallin domain (ACD). Finger millet (Eleusine coracana) is a climate-resilient, calcium-rich allotetraploid cereal of the semi-arid tropics whose HSP20 repertoire had not been catalogued. The present study is an entirely computational (in silico) analysis of the chromosome-scale reference genome of finger millet (NCBI GenBank assembly GCA_032690845.1, cultivar KNE 796-S). Mining the predicted proteome with the ACD profile (Pfam PF00011) and confirming every candidate by NCBI CD-search recovered 76 non-redundant ACD-bearing HSP20 genes (EcHSP20-1-EcHSP20-76). Based on phylogeny and TargetP-predicted localization, the members were classified into ten subfamilies: seven cytosolic/nuclear classes (C-I to C-VII, 60 members) together with chloroplastic (11), mitochondrial (3) and endoplasmic-reticulum (2) groups. The proteins ranged from 110 to 355 amino acids (12.1-39.2&#xa0;kDa) with theoretical pI of 4.85-9.69. The 76 loci were distributed over 14 of the 18 chromosomes and were conspicuously absent from chromosomes 8&#xa0;A, 8B, 9&#xa0;A and 9B, with pronounced clustering on chromosomes 1, 2, 3 and 6. Duplication analysis detected 149 paralogous pairs (49 homoeologous, 80 segmental/dispersed and 18 tandem); 147 of 148 pairs for which substitution rates could be calculated returned Ka/Ks&#x2009;<&#x2009;1 (mean 0.20), indicating strong purifying selection consistent with retention after whole-genome/allopolyploid duplication. Promoter analysis (PlantCARE) revealed enrichment of abscisic-acid-responsive (ABRE), MYB/MYC drought-related, STRE, DRE, low-temperature (LTR) and methyl-jasmonate/salicylic-acid elements, whereas canonical heat-shock elements (HSE) were not recovered. Expression profiling against a public drought transcriptome (SRP081350) showed that about half of the genes (39 of 76) are transcribed in leaf tissue, the expressed fraction being dominated by the cytosolic class C-I. This first finger-millet HSP20 catalogue provides a verified, reproducible framework and nominates computationally predicted candidate genes for future functional work on thermotolerance in cereals.

Allotetraploid

Chromosome-scale assembly with improved annotation provides insights into breed-wide genomic structure and diversity in domestic cats.

INTRODUCTION: Comprehensive genomic resources offer insights into biological features, including traits/disease-related genetic loci. The current reference genome assembly for the domestic cat (Felis catus), Felis_Catus_9.0 (felCat9), derived from sequences of the Abyssinian cat, may inadequately represent the general cat population, limiting the extent of deducible genetic variations. OBJECTIVES: The goal was to develop Anicom American Shorthair 1.0 (AnAms1.0), a reference-grade chromosome-scale cat genome assembly. METHODS: In contrast to prior assemblies relying on Abyssinian cat sequences, AnAms1.0 was constructed from the sequences of more popular American Shorthair breed, which is related to more breeds than the Abyssinian cat. By combining advanced genomics technologies, including PacBio long-read sequencing and Hi-C- and optical mapping data-based sequence scaffolding, we compared AnAms1.0 to existing Felidae genome assemblies (20 scaffolds, scaffolds N50&#xa0;>&#xa0;150 Mbp). Homology-based and ab initio gene annotation through Iso-Seq and RNA-Seq was used to identify new coding genes and splice variants. RESULTS: AnAms1.0 demonstrated superior contiguity and accuracy than existing Felidae genome assemblies. Using AnAms1.0, we identified over 1.5 thousand structural variants and 29 million repetitions compared to felCat9. Additionally, we identified > 1,600 novel protein-coding genes. Notably, olfactory receptor structural variants and cardiomyopathy-related variants were identified. CONCLUSION: AnAms1.0 facilitates the discovery of novel genes related to normal and disease phenotypes in domestic cats. The analyzed data are publicly accessible on Cats-I (https://cat.annotation.jp/), which we established as a platform for accumulating and sharing genomic resources to discover novel genetic traits and advance veterinary medicine.

Animals

Haplotype-specific expression of a terpene synthase underlies linalool variation in the grapevine cultivar Riesling.

Grapevine cultivars vary widely in monoterpenoid content, yet the genetic and regulatory mechanisms underlying this variation remain poorly characterized beyond highly aromatic Muscat types. We profiled free volatiles and monoterpenoid glycosides in a Riesling &#xd7; Cabernet Sauvignon F1 mapping population, revealing extensive variation and transgressive segregation consistent with multigenic control. QTL mapping identified 70 significant loci associated with 48 volatile compounds and monoterpene glycosides, including two major QTLs explaining 33.6% and 33.4% of phenotypic variance in (3S)-linalool accumulation. Integration of haplotype-resolved transcriptomics with metabolite data, enabled by a chromosome-scale diploid Riesling genome assembly, resolved a (3S)-linalool/nerolidol synthase cluster on chromosome 10 and identified VviTPS54 as the strongest candidate underlying linalool variation. VviTPS54 exhibited haplotype-specific expression strongly correlated with (3S)-linalool accumulation across genotypes, while no QTL was detected at the 1-deoxy-D-xylulose-5-phosphate synthase 1 (VviDXS1) locus previously identified in Muscat cultivars. In addition, VviDXS1 expression was not correlated with terpene levels, indicating that regulatory variation within terpene synthase clusters, rather than methylerythritol phosphate (MEP) pathway flux, drives monoterpenoid composition in this population. These results establish regulatory variation of terpene synthases as a key mechanism underlying monoterpenoid diversity in grapevine and demonstrate that resolving such variation requires haplotype-phased genome assemblies coupled with haplotype-resolved transcriptomics to detect allele-specific expression differences at complex, heterozygous loci.

Grapevine

A single hybrid origin of cultivated peanut.

This study, the first in a three-part series, lays the foundation for understanding the origin of the peanut crop (Arachis hypogaea). Its subsequent evolution is explored in the two papers that follow. The evidence that A. hypogaea originated from a single hybridization event between Arachis duranensis and Arachis ipa&#xeb;nsis less than 10&#x2009;000&#x2009;years ago was already very strong. Here, we extend this evidence using more than 1600 single-nucleotide polymorphisms to make an almost exhaustive comparison of wild Arachis section germplasm conserved ex situ with the A and B subgenomes of divergent, sequenced cultivated peanuts. The wild relatives of peanut are highly selfing and their geocarpy means they plant their own seeds, allowing them to persist as discrete populations for millennia. This unusual biology creates a rare opportunity for genetic archaeology: ancestral lineages can be identified with exceptional precision. Our results reaffirm a single origin for the cultigen, identifying A. duranensis from&#xa0;R&#xed;o Seco and A. ipa&#xeb;nsis K 30076 as the closest known relatives of the A and B subgenomes of peanut. As a genomic resource, we generated a chromosome-scale assembly of the R&#xed;o Seco A. duranensis K 30065 and confirmed that it is more closely related to the A subgenome of peanut than the current reference genome (V14167). Even if somewhat closer wild accessions were found through new field collections, they would still belong to the same ancestral lineage. With this level of evidence, the origin of peanut is now known in greater detail than that of any other ancient polyploid crop.

Arachis

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&#xa0;Gb and represented 23 pairs of chromosomes with an NG50 of 150&#xa0;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

A Chromosome-Level Genome Assembly of the Potato Leafhopper Empoasca fabae (Hemiptera: Cicadellidae).

The potato leafhopper, Empoasca fabae (Harris, 1841), is a highly polyphagous, migratory insect pest of eastern North America that feeds on more than 200 herbaceous and woody plant species, causing substantial losses to forage and field crops. Despite its agricultural and ecological importance, no genome has been available for this species. Here, we present the first chromosome-level genome assembly of E. fabae, generated from Oxford Nanopore long reads, Illumina short reads, and Omni-C proximity-ligation data. The final assembly spans 908&#x2005;Mb across 132 scaffolds, with 99.8% of the assembly captured in ten chromosome-length scaffolds (nine autosomes and an X chromosome) with a scaffold N50 of 96.2&#x2005;Mb. The assembly is highly complete, recovering 92.9% of conserved hemipteran single-copy orthologs from protein annotations, and is composed of 47.6% repetitive sequence, dominated by long terminal repeat retrotransposons and unclassified elements. Read-depth comparison between male and female individuals supports assignment of a single sex-linked chromosome, consistent with an XO sex determination system. BRAKER3 gene annotation predicted 31,406 protein-coding genes after retaining the longest isoform per locus. Comparative genome analysis of the two closest related Typhlocybinae species with genomes available, Matsumurasca onukii and Hebata decipiens, revealed extensive chromosome-scale collinearity while defining a shared core gene repertoire. This reference genome provides a foundation for comparative and population genomic studies and for investigating genetic traits in this economically important crop pest species.

Animals