SEARCH · Search PubMed

Results for “Genome assembly”

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.

SourceResearch connectionFrom yearThrough year

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

At least 307 records · Page 17Linked to original sources

PubMed2026

Chromosome-scale genomes and population resequencing resolve subgenome diversity and halophyte adaptation in Salicornia.

Amid escalating water scarcity and groundwater depletion, halophytes such as Salicornia (Amaranthaceae) represent valuable models for extreme salt tolerance and hold promise for saltwater-based agriculture. Here, we show chromosome-scale genome assemblies for six Salicornia species, revealing four distinct subgenomes, reconciling our assemblies with two existing reference genomes (S. ramosissima UK and S. europaea China), correcting chromosome numbering and orientation. Comparative analyses across ploidy levels demonstrate genome expansion in North American lineages driven by Gypsy retrotransposons, and lineage-specific expansions of two gene families implicated in stress metabolism. Phylogenetic and population-structure analyses of a global resequencing panel of 318 accessions resolve interspecific relationships and establish curated germplasm collections for future crop breeding. Genetic analyses uncover a contrasting population-genetic signal on chromosome 6A between two species, highlighting an OSCA calcium-permeable channel gene as a candidate locus for osmotic adaptation. Together, these resources establish a genomic framework for Salicornia that supports evolutionary studies of halophyte adaptation and crop development.

Chenopodiaceae↗

PubMed2025

A complete diploid human genome benchmark for personalized genomics.

Human genome resequencing typically involves mapping reads to a reference genome to call variants; however, this approach suffers from both technical and reference biases, leaving many duplicated and structurally polymorphic regions of the genome unmapped. Consequently, existing variant benchmarks, generated by the same methods, fail to assess these complex regions. To address this limitation, we present a telomere-to-telomere genome benchmark that achieves near-perfect accuracy (i.e. no detectable errors) across 99.4% of the complete, diploid HG002 genome. This benchmark adds 701.4 Mb of autosomal sequence and both sex chromosomes (216.8 Mb), totaling 15.3% of the genome that was absent from prior benchmarks. We also provide a diploid annotation of genes, transposable elements, segmental duplications, and satellite repeats, including 39,144 protein-coding genes across both haplotypes. To facilitate application of the benchmark, we developed tools for measuring the accuracy of sequencing reads, phased variant call sets, and genome assemblies against a diploid reference. Genome-wide analyses show that state-of-the-art de novo assembly methods resolve 2-7% more sequence and outperform variant calling accuracy by an order of magnitude, yielding just one error per 100 kb across 99.9% of the benchmark regions. Adoption of genome-based benchmarking is expected to accelerate the development of cost-effective methods for complete genome sequencing, expanding the reach of genomic medicine to the entire genome and enabling a new era of personalized genomics.

Journal Article↗

PubMed2025

Where Did the Y Chromosome in the Spiny Rat Go, and How Did It Get There?

The XX/XY sex chromosome system is highly conserved across mammals, with rare exceptions where males lack a Y chromosome. Among these is the genus Tokudaia, a group of spiny rats comprising three species with unique sex chromosome systems deviating from the typical XX/XY pattern. While Tokudaia osimensis and Tokudaia tokunoshimensis have completely lost the Y chromosome, they retain some Y-linked genes on the X chromosome. In contrast, Tokudaia muenninki retains large sex chromosomes where both the X and Y chromosomes have fused with an autosome pair, carrying multi-copied Y-linked genes, including Sry. In this study, we generated chromosome-level genome assemblies for male individuals of all three Tokudaia species. By investigating loci typically associated with rodent Y-linked genes, we characterized sequences derived from the Tokudaia Y-chromosomal most recent common ancestor (Tokudaia Y-MRCA) and traced their evolutionary trajectories. Our analyses revealed that an initial X-to-Y translocation of a sequence containing the boundary-associated segmental duplication in a common ancestor of Tokudaia marked the beginning of their unique sex chromosome evolution. The boundary-associated segmental duplication, uniquely multi-copied in Tokudaia, facilitated further rearrangements through nonallelic homologous recombination and duplications. These processes culminated in subsequent Y-to-X translocations and duplications, leading to the complete loss of the Y chromosome as a distinct entity while preserving Y-linked genes in a multicopy state on the X chromosome. These findings highlight Tokudaia's rapid sex chromosome evolution within 3 million years and provide insights into the mechanisms underlying Y chromosome loss, contributing to a broader understanding of sex chromosome evolution in rodents.

Animals↗

PubMed2022

The genome sequence of the Adonis blue, Lysandra bellargus (Rottemburg, 1775).

We present a genome assembly from an individual female Lysandra bellargus (the Adonis blue; Arthropoda; Insecta; Lepidoptera; Lycaenidae). The genome sequence is 529 megabases in span. The majority of the assembly (99.93%) is scaffolded into 46 chromosomal pseudomolecules with the W and Z sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 15.6 kilobases in length. Gene annotation of this assembly on Ensembl has identified 13,249 protein coding genes.

Adonis blue↗

PubMed2025

Characterization of microbial dark matter at scale with MetaSBT and taxonomy-aware Sequence Bloom Trees.

Metagenomics has become a powerful tool for studying microbial communities, allowing researchers to investigate microbial diversity within complex environmental samples. Recent advances in sequencing technology have enabled the recovery of near-complete microbial genomes directly from metagenomic samples, also known as metagenome-assembled genomes (MAGs). However, accurately characterizing these genomes remains a significant challenge due to the presence of sequencing errors, incomplete assembly, and contamination. Here we present MetaSBT, a new tool for organizing, indexing, and characterizing microbial reference genomes and MAGs. It is able to identify clusters of genomes at all seven taxonomic levels, from the kingdom all the way down to the species level, using the Sequence Bloom Tree (SBT) data structure that relies on Bloom Filters (BFs) to index massive amounts of genomes based on their k-mers composition. We have built an initial set of databases composed of over 190 thousand viral genomes from NCBI GenBank and public sources grouped into sequence consistent clusters at different taxonomic levels, making it the first software solution for the classification of viruses at different ranks, including still unknown ones. This results in the definition of over 40 thousand species clusters where ~80% do not match with any known viral species in reference databases to date. Furthermore, we show how our databases can be used as a new basis for existing quantitative metagenomic profilers to unlock the detection of unknown microbes and the estimation of their abundance in metagenomic samples. Finally, the framework is released open-source and, along with its public databases, is fully integrated into the Galaxy Platform enabling broad accessibility.

metagenome-assembled genomes↗

PubMed2025

The chromosome-level genome of Stylosanthes guianensis provides insights into genome evolution and environmental adaptation.

Stylosanthes guianensis is a leguminous forage crop of significant economic importance, primarily distributed in tropical and subtropical regions. It exhibits strong adaptability to various stresses, yet the genetic basis underlying this trait remains unclear. In this study, we constructed the first chromosome-scale reference genome of S. guianensis using a combination of Nanopore and Hi-C sequencing technologies. The assembled genome size is 1254 Mb, with 10 pseudochromosomes. Using Nanopore full-length transcriptome data, we generated high-quality transcript-level gene annotations, identifying 36 585 gene models and 110 601 transcripts. The repetitive sequences in S. guianensis account for 79.16% of the genome, with the extensive expansion of Gypsy elements in long terminal repeats contributing to its genome size enlargement. Comparative genomic and transcriptomic analyses revealed that flavonoid metabolism plays a pivotal role in stress adaptation, providing new insights into the genetic basis of stress tolerance. Additionally, we generated whole-genome methylation profiles under cold treatment and control conditions, offering valuable data for future epigenomic research. These findings provide essential molecular resources for understanding stress resilience in S. guianensis and advancing its molecular breeding.

Genome, Plant↗

PubMed2001

Design of a compartmentalized shotgun assembler for the human genome.

Two different strategies for determining the human genome are currently being pursued: one is the "clone-by-clone" approach, employed by the publicly funded project, and the other is the "whole genome shotgun assembler" approach, favored by researchers at Celera Genomics. An interim strategy employed at Celera, called compartmentalized shotgun assembly, makes use of preliminary data produced by both approaches. In this paper we describe the design, implementation and operation of the "compartmentalized shotgun assembler".

Chromosomes, Artificial, Bacterial↗

PubMed2022

The genome sequence of the plain-faced dronefly, Eristalis arbustorum (Linnaeus, 1758).

We present a genome assembly from an individual female Eristalis arbustorum (the plain-faced dronefly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 451 megabases in span. The majority of the assembly (94.71%) is scaffolded into 6 chromosomal pseudomolecules, with the X sex chromosome assembled. The complete mitochondrial genome was also assembled and is 16.0 kilobases in length.

Diptera↗

PubMed2026

The genome sequence of a nematode, Thelazia callipaeda Railliet & Henry, 1910 (Rhabditida: Thelaziidae).

We present a genome assembly of Thelazia callipaeda (nematode; Nematoda; Chromadorea; Rhabditida; Thelaziidae). The genome sequence has a total length of 117.59 megabases. Most of the assembly (75.82%) is scaffolded into 4 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has been assembled, with a length of 13.66 kilobases.

Thelazia callipaeda; nematode; genome sequence; ch↗

PubMed2006

A second generation radiation hybrid map to aid the assembly of the bovine genome sequence.

BACKGROUND: Several approaches can be used to determine the order of loci on chromosomes and hence develop maps of the genome. However, all mapping approaches are prone to errors either arising from technical deficiencies or lack of statistical support to distinguish between alternative orders of loci. The accuracy of the genome maps could be improved, in principle, if information from different sources was combined to produce integrated maps. The publicly available bovine genomic sequence assembly with 6x coverage (Btau_2.0) is based on whole genome shotgun sequence data and limited mapping data however, it is recognised that this assembly is a draft that contains errors. Correcting the sequence assembly requires extensive additional mapping information to improve the reliability of the ordering of sequence scaffolds on chromosomes. The radiation hybrid (RH) map described here has been contributed to the international sequencing project to aid this process. RESULTS: An RH map for the 30 bovine chromosomes is presented. The map was built using the Roslin 3000-rad RH panel (BovGen RH map) and contains 3966 markers including 2473 new loci in addition to 262 amplified fragment-length polymorphisms (AFLP) and 1231 markers previously published with the first generation RH map. Sequences of the mapped loci were aligned with published bovine genome maps to identify inconsistencies. In addition to differences in the order of loci, several cases were observed where the chromosomal assignment of loci differed between maps. All the chromosome maps were aligned with the current 6x bovine assembly (Btau_2.0) and 2898 loci were unambiguously located in the bovine sequence. The order of loci on the RH map for BTA 5, 7, 16, 22, 25 and 29 differed substantially from the assembled bovine sequence. From the 2898 loci unambiguously identified in the bovine sequence assembly, 131 mapped to different chromosomes in the BovGen RH map. CONCLUSION: Alignment of the BovGen RH map with other published RH and genetic maps showed higher consistency in marker order and chromosome assignment than with the current 6x sequence assembly. This suggests that the bovine sequence assembly could be significantly improved by incorporating additional independent mapping information.

Animals↗

PubMed2026

Genomic and biosynthetic landscape of high-temperature Daqu microbiome.

As the core starter for Chinese Baijiu, high-temperature Daqu is produced through open solid-state fermentation with recurrent inoculation by mature Daqu, forming a rich yet largely untapped reservoir of genomes and bioactive compounds. This study constructs the High-temperature Daqu Fermentation Microbiome catalog using 463 metagenomes spanning the full fermentation cycle. The catalog comprises 4,264 metagenome-assembled genomes that are dereplicated into 252 representative genome-based species, 82 % of which are absent from current global food microbiome databases. It further contains 14.3 million non-redundant genes, of which 17.3 % are novel, and 17,031 biosynthetic gene clusters, of which 62.63 % are novel, thereby substantially expanding the known genomic and biosynthetic space of food microbiomes. Genome-resolved analyses revealed a U-shaped ecological trajectory, shifting from early Bacillus velezensis-enriched assemblages to transient dominance of lactic acid bacteria during peak thermogenesis, before returning in late fermentation to thermotolerant, spore-forming Bacillota and Actinomycetota. In parallel, biosynthetic potential was further organized into four recurrent, stage-enriched profiles, from RiPP-rich thermogenic states to mature-state assemblages enriched in PKS-, NRPS-, and terpene-related capacities, with Bacillus, Kroppenstedtia, and Saccharopolyspora constituting the principal biosynthetic reservoir. Together, this work uncovers a largely unexplored genomic and biosynthetic reservoir in high-temperature Daqu fermentation, providing a target resource for mining thermotolerant industrial enzymes, flavor-related genes, and bioactive metabolites with biotechnological potential.

Microbiota↗

PubMed2026

theBIGbam: compression and interactive exploration of large-scale sequencing alignments with circular mapping support.

SUMMARY: theBIGbam (github.com/bhagavadgitadu22/theBIGbam) is a genome browser and alignment viewer designed for massive metagenomic and metatranscriptomic datasets. The tool takes BAM files containing read alignments, together with genome assemblies in FASTA format or annotated genome sequences in GenBank format. Alternatively, it can start from raw FASTQ reads and generate alignments using a modified mapper that supports circular genomes, enabling seamless read mapping across genome ends. theBIGbam can compress hundreds of gigabytes of input files 10- to 100-fold into dedicated databases while retaining key per-position information, including coverage depth and recurrent mismatches, insertions, and deletions between reads and the reference. These databases can be served to a local web browser, enabling interactive exploration of any contig in any sample using DNAFeaturesViewer for genome maps and Bokeh for mapping-derived features. Contig-sample pairs available for visualization can be filtered using a range of summary metrics calculated per contig, per sample, and per contig-sample pair to guide users toward the most relevant signals. Through its interactive visualization, theBIGbam facilitates the exploration of complex datasets, while its integrated database-combining assembly features, annotated features, and mapping-derived features-provides the information needed to investigate biological hypotheses systematically. Designed to complement existing browsing tools like IGV and Anvi'o, theBIGbam is particularly suited for examining misassemblies, subpopulations, microdiversity, and contig topology in large-scale datasets. AVAILABILITY AND IMPLEMENTATION: theBIGbam is an open-source Rust/Python package that can be installed from Bioconda or PyPI. The source code and documentation are available on GitHub (github.com/bhagavadgitadu22/theBIGbam).

Software↗

PubMed2025

Genomic analysis of Dasiphora on the Qinghai-Tibet Plateau provides insights into genetic divergence and flower color variation.

The Qinghai-Tibet Plateau (QTP) harbors diverse alpine flora, including the ecologically significant shrubs Dasiphora fruticosa and D. glabra, for which taxonomic uncertainties remain and adaptive mechanisms are still poorly understood. Based on high-quality genome assembly, population resequencing, and multi-omics integration, we elucidated their evolutionary divergence and flower color genetics. Chromosome-level haplotype-resolved genomes were assembled: autotetraploid D. fruticosa (929.99 Mb) and diploid D. glabra (450.89 Mb). Phylogenetic analysis showed that the tetraploid D. fruticosa and D. glabra in this study clustered together, while the diploid D. fruticosa sequenced by previous research formed a distinct lineage clustered outside. Consistently, population structure analysis of 55 samples revealed three major clades, with D. fruticosa further subdivided into two divergent branches. Additionally, hybridization events detected by Admixture, coupled with ploidy complexity identified via flow cytometry highlight the intricate genetic relationships within this genus. Adaptive gene families expanded in antioxidant (flavonoid synthesis) and secondary metabolism pathways, adapting to ultraviolet radiation and cold stress. Natural selection analysis identified 193 candidate genes (e.g., TFB5 in the DNA repair pathway), predominantly localized to chromosome 5, which are potential candidates for high-altitude adaptation. Transcriptome and metabolome analyses showed D. fruticosa's yellow petals derive from flavonol (quercetin) accumulation, while D. glabra's white petals result from proanthocyanidin biosynthesis via high LAR/ANR expression. This study provides insights into the taxonomic revision and adaptive genetic divergence of alpine plants, and offers a foundation for horticultural improvement of Dasiphora.

Flowers↗

PubMed2007

Comparative genomic analysis of the mouse and rat amylase multigene family.

The rat and mouse amylase gene families were characterized using sequence data from the UCSC genome assembly. We found that the rat genome contains one amylase-1 and two amylase-2 genes, lying close to one another on the same chromosome. Detailed analysis revealed at least six additional amylase pseudogenes in the rat genome in the region adjacent to the amylase-2 genes. In contrast, the mouse has one amylase-1 gene and five amylase-2 genes; the latter are tandemly and systematically arranged on the same chromosome and were generated by segmental duplication. Detailed analysis revealed that the mouse has two amylase pseudogenes, located 5' to the five amylase-2 segments. Thus, the amylase genes of mouse and rat tend to be amplified; the sequences of some of them are fixed while others have become pseudogenes during evolution. This is the second report of amylase genomic organization in mammals and the first in the rodents.

Amylases↗

PubMed2026

Flavobacteria consume nitrous oxide produced by partial denitrifiers in coastal sediments.

Nearly one-fifth of global emissions of the potent greenhouse gas nitrous oxide (N2O) originate from the ocean, particularly from nutrient-polluted coastal regions. Permeable (sandy) sediments, which cover half of the continental shelf worldwide, are potential sources of N2O due to increasing nutrient inputs from urbanization and agriculture. Yet, the microbial processes determining N2O emissions in these dynamic and unique ecosystems remain understudied. Here, we combined environmental measurements, bacterial cultivation, and genomic analyses to understand the microbes and processes controlling N2O cycling in permeable sediments from Port Phillip Bay (Australia). We established a genomic resource comprising 249 metagenome-assembled genomes and 95 new isolate genomes. Genome-based metabolic reconstructions and culture-based gas measurements revealed that diverse bacteria in these sediments produce N2O through incomplete denitrification pathways. However, these bacteria co-occurred with highly abundant clade II N2O-reducing bacteria from the Flavobacteriaceae family. Kinetic profiling showed that both clade II nosZ flavobacterial isolates and whole sand communities exhibited a low apparent affinity for N2O under the tested experimental conditions, expanding the currently limited kinetic data available for N2O reducing microorganisms from coastal permeable sediments, including flavobacterial clade II N2O reducers. Collectively, these findings indicate that abundant N₂O reducing communities can substantially consume N2O within permeable sediments, thus limiting N2O accumulation despite active N2O production. Together with previous hydrodynamic models predicting low N2O release from permeable sediments, our results highlight the important role of specialized microbial communities in regulating N2O cycling under increasing nutrient pollution.

Nitrous Oxide↗

PubMed2005

Identification of transposable elements using multiple alignments of related genomes.

Accurate genome-wide cataloging of transposable elements (TEs) will facilitate our understanding of mobile DNA evolution, expose the genomic effects of TEs on the host genome, and improve the quality of assembled genomes. Using the availability of several nearly complete Drosophila genomes and developments in whole genome alignment methods, we introduce a large-scale comparative method for identifying repetitive mobile DNA regions. These regions are highly enriched for transposable elements. Our method has two main features distinguishing it from other repeat-finding methods. First, rather than relying on sequence similarity to determine the location of repeats, the genomic artifacts of the transposition mechanism itself are systematically tracked in the context of multiple alignments. Second, we can derive bounds on the age of each repeat instance based on the phylogenetic species tree. We report results obtained using both complete and draft sequences of four closely related Drosophila genomes and validate our results with manually curated TE annotations in the Drosophila melanogaster euchromatin. We show the utility of our findings in exploring both transposable elements and their host genomes: In the study of TEs, we offer predictions for novel families, annotate new insertions of known families, and show data that support the hypothesis that all known TE families in D. melanogaster were recently active; in the study of the host, we show how our findings can be used to determine shifts in the eu-heterochromatin junction in the pericentric chromosome regions.

Animals↗

PubMed2026

Mechanistic Perspectives From Genomics and Pangenomics of Medicinal and Aromatic Plants: Linking Genome Architecture to Phytochemical Diversity.

Medicinal and aromatic plants (MAPs) produce a remarkable diversity of specialized metabolites with significant pharmaceutical, nutraceutical, and industrial value. Although advances in long-read sequencing, chromosome-scale genome assembly, and pangenomics have greatly expanded genomic resources, the mechanistic links between genome architecture and phytochemical diversity remain incompletely understood. The present review synthesizes current evidence describing how structural genomic variation may contribute to phytochemical diversity, while acknowledging that many proposed genome-to-metabolite relationships require further experimental validation. Examples illustrate how genome architecture is associated with specialized-metabolite biosynthesis through multiple regulatory processes. However, the strength of supporting evidence varies considerably among MAP species. Moreover, relatively few genome-to-metabolite relationships have been confirmed through direct functional validation. We further discuss how pangenomics, multiomics integration, genome editing, synthetic biology, and artificial intelligence support the discovery, validation, and engineering of specialized metabolic pathways. Casual conclusions are evaluated according to the strength of available evidence, highlighting where causal relationships have been experimentally established and where conclusions remain primarily association-based. Overall, this review provides an integrated conceptual and evidence-based perspective summarizing proposed relationships between genome architecture and phytochemical diversity and outlines future priorities for functional genomics, precision breeding, metabolic engineering, and sustainable utilization of MAPs.

artificial intelligence↗

PubMed2006

Chicken genomics resource: sequencing and annotation of 35,407 ESTs from single and multiple tissue cDNA libraries and CAP3 assembly of a chicken gene index.

Its accessibility, unique evolutionary position, and recently assembled genome sequence have advanced the chicken to the forefront of comparative genomics and developmental biology research as a model organism. Several chicken expressed sequence tag (EST) projects have placed the chicken in 10th place for accrued ESTs among all organisms in GenBank. We have completed the single-pass 5'-end sequencing of 37,557 chicken cDNA clones from several single and multiple tissue cDNA libraries and have entered 35,407 EST sequences into GenBank. Our chicken EST sequences and those found in public databases (on July 1, 2004) provided a total of 517,727 public chicken ESTs and mRNAs. These sequences were used in the CAP3 assembly of a chicken gene index composed of 40,850 contigs and 79,192 unassembled singlets. The CAP3 contigs show a 96.7% match to the chicken genome sequence. The University of Delaware (UD) EST collection (43,928 clones) was assembled into 19,237 nonredundant sequences (13,495 contigs and 5,742 unassembled singlets). The UD collection contains 6,223 unique sequences that are not found in other public EST collections but show a 76% match to the chicken genome sequence. Our chicken contig and singlet sequences were annotated according to the highest BlastX and/or BlastN hits. The UD CAP3 contig assemblies and singlets are searchable by nucleotide sequence or key word (http://cogburn.dbi.udel.edu), and the cDNA clones are readily available for distribution from the chick EST website and clone repository (http://www.chickest.udel.edu). The present paper describes the construction and normalization of single and multiple tissue chicken cDNA libraries, high-throughput EST sequencing from these libraries, the CAP3 assembly of a chicken gene index from all public ESTs, and the identification of several nonredundant chicken gene sets for production of custom DNA microarrays.

Animals↗