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At least 127 records · Page 7Linked to original sources

The first near telomere-to-telomere genome assembly of Panulirus homarus homarus.

The scalloped spiny lobster (Panulirus homarus homarus) is an economically important decapod crustacean with high aquaculture potential. Several chromosome-level genomes of this species have been reported. But the lobster or even entire shrimps did not have the telomere-to-telomere assembly until now. Therefore, we present the first near telomere-to-telomere genome assembly of P. h. homarus generated by using pure Oxford Nanopore Technologies ultra-long (ONT) reads and Hi-C sequencing. The final assembly anchored to 73 chromosomes with a contig N50 of 41.1 Mb. 73 chromosomes contain entire 146 telomeres, of which 51 chromosomes have no gaps. A total of 38,396 protein-coding genes were predicted. BUSCO analysis showed a completeness score of 99.8%, indicating a high degree of assembly completeness. This high-quality genomic dataset provides a valuable resource for comparative genomics, evolutionary studies, and genome-assisted breeding of spiny lobsters.

Animals↗

A chromosome-level genome assembly and annotation of Cercis chuniana (Fabaceae).

The genus Cercis L., at the base of the subfamily Cercidoideae of Fabaceae, is known for its ecological adaptability and significant medicinal, ornamental, and economic value. However, the lack of a high-quality genome hinders the understanding of the evolution of Cercis and Fabaceae. In this study, we present a chromosome-level genome of Cercis chuniana by combining Illumina short reads, PacBio HiFi long reads, and Hi-C data. The final genome size is 355.53 Mb, consisting of 12 contigs with a N50 of 42.34 Mb. Notably, 344.24 Mb, corresponding to 96.82% of the genome, was anchored to seven chromosomes. The assembly comprises 24.83% repetitive sequences, including 19.32% long terminal repeats. Additionally, a total of 33,837 protein-coding genes were predicted in the genome, with 32,709 (96.67%) genes successfully annotated. The high-quality genome assembly of C. chuniana not only bridges the existing gap in genomic data and offers important resources for molecular studies of this species, but also provides essential insights for future studies on speciation, functional and comparative genomics within the Fabaceae family.

Genome, Plant↗

TruMatch--a BLAST post-processor that identifies bona fide sequence matches to genome assemblies.

SUMMARY: BLAST is a widely used alignment tool for detecting matches between a query sequence and entries in nucleotide sequence databases. Matches (high-scoring pairs, HSPs) are assigned a score based on alignment length and quality and, by default, are reported with the top-scoring matches listed first. For certain types of searches, however, this method of reporting is not optimal. This is particularly true when searching a genome sequence with a query that was derived from the same genome, or a closely related one. If the genome is complex and the assembly is far from complete, correct matches are often relegated to low positions in the results, where they may be easily overlooked. To rectify this problem, we developed TruMatch--a program that parses standard BLAST outputs and identifies HSPs that involve query segments with unique matches to the assembly. Candidates for bona fide matches between a query sequence and a genome assembly are listed at the top of the TruMatch output. AVAILABILITY: TruMatch is written in Perl and is freely available to non-commercial users via web download at the URL: http://genome.kbrin.uky.edu/fungi_tel/TruMatch/

Algorithms↗

Chromosomal-level genome assembly of minute pirate bug Orius nagaii Yasunaga, 1993 (Hemiptera: Anthocoridae).

Species of the genus Orius, diminutive predatory insects that act as natural enemies of other arthropods, are frequently employed in agricultural pest management for controlling various pests, such as thrips, mites, aphids, whiteflies, etc. However, the scarcity of high-quality genomic resources for these predators hinders our comprehension of their population evolution and predation ecology. Consequently, we assembled and annotated a chromosomal-scale genome of Orius nagaii by collating PacBio and Illumina sequencing and Hi-C genomic analysis techniques. The final genome assembly size 152.62 Mb, with scaffold and contig N50 lengths of 11.53 and 2.39 Mb, respectively. It is organized into 12 pairs of autosomes and a pair of XY sex chromosomes. The quality assessment of the genomic data with BUSCO revealed a completeness of 98.5% (n = 1,367). Also, 11,917 protein-coding genes were discovered, with 94.28% of them having functional annotations. The high-quality genome of O. nagaii produced serves as a valuable resource for comprehending the interactions between predatory natural enemies and hosts, along with their evolutionary trajectories.

Animals↗

Using temporal reasoning for genome map assembly.

Genomic maps are an indispensable tool for molecular biologists; their modelling has to take into account representation as well as computational issues. The algorithmic complexity of the assembly task is already huge and is even made worse when one wishes to deal with inconsistencies and provide generic tools. This work presents an algorithm tackling the assembly problem by using temporal reasoning techniques. The algorithm has to transform the initial input data, i.e. qualitative and quantitative relations between entities that appear on the maps, so that temporal reasoning algorithms can be applied successfully; this is achieved by performing a partition of these relations upon their relative orientation, creating islets of relations in which reasoning mechanisms are applied. The implementation of the algorithm is based on a temporal reasoning software, taken as is, which gives a high genericity since any improvement in this software (such as efficiency or the management of flexible constraints) can be immediately used by the algorithm.

Algorithms↗

Near-complete reference genome assembly of Hoya carnosa.

Hoya R. Br. is the largest genus in the tribe Marsdenieae (Apocynaceae), comprising 350-450 species. Hoya species are popular in horticulture for their distinctive floral traits and fragrances, primarily sourced from domestication and mutation breeding. However, the lack of molecular analysis for floral morphological traits has limited their cultivation and application. In this study, we assembled a near-complete reference genome for H. carnosa, the model species of the genus, using PacBio HiFi reads and Hi-C method. The genome size was approximately 465.7 Mb with a contig N50 of 39.3 Mb. 99.7% of the sequences were anchored to 11 pseudochromosomes, and the assembly achieved a BUSCO score of 98.5%. We predicted 24,309 protein-coding genes, of which 90.2% (21,927) were functionally annotated. This high-quality genome provides a valuable reference for the research of evolution, conservation and molecular breeding in Hoya.

Genome, Plant↗

GENOTRACE: cDNA-based local GENOme assembly from TRACE archives.

UNLABELLED: GENOTRACE identifies the genomic organization for a cDNA using raw data from genome sequencing projects in progress (trace archives). Local genomic contigs are generated, allowing for example the design of PCR primers in intronic sequences to amplify coding regions of a gene, needed for example for mutation or SNP detection. AVAILABILITY: The package and examples of output files can be downloaded from http://rat.niob.knaw.nl/GENOTRACE

Archives↗

Chromosome-level genome assembly of Ceroplastes pseudoceriferus Green, 1935 (Hemiptera: Coccidae).

Soft scales (Hemiptera: Coccidae) are significant polyphagous pests and majority of which are invasive species. The 364.14 Mb chromosome-level genome of Ceroplastes pseudoceriferus was assembled in this work, with a contig N50 length of 6.16 Mb and scafold N50 length of 21.24 Mb. Approximately 99.89% of assembled sequences were anchored into 18 chromosomes with the assistance of Hi-C reads. Furthermore, approximately 53.98% of the genome was composed of repetitive elements. In total, 10,475 protein-coding genes were predicted, of which 9503 (90.72%) genes were functionally annotated. The BUSCO analysis demonstrated the completeness of the genome annotation is 92.54%. This genome represents first high-quality chromosome level assembly of Coccidae, thereby advancing our knowledge of Coccidae insects and developing effective management strategies that protect crops, forests, and natural ecosystems.

Animals↗

T2T and chromosome-level genome assemblies provide insights into the genetic basis of bioactive compound biosynthesis and environmental adaptation in licorice.

Licorice is an important medicinal herb worldwide, including three Chinese Pharmacopoeia species (Glycyrrhiza uralensis, G. inflata, G. glabra), with bioactive compounds crucial for disease treatment and industrial applications. However, the genetic mechanisms underlying the biosynthesis, diversification, and environmental adaptation of bioactive compounds in Glycyrrhiza species have long remained unclear. Herein, we assembled a gapless telomere-to-telomere (T2T) genome of G. uralensis with resolved telomeres and centromeres and three significantly improved high-quality chromosome-level Glycyrrhiza genomes, alongside a variation map of 188 wild accessions. Population analysis revealed evolutionary divergence among species, with selection signals linked to medicinal compound pathways. We identified 4CL5 as a key gene for stress response and compound synthesis. GWAS validation highlighted the GiPHL1-Gi4CL5 module's role in licochalcone A accumulation and enhanced stress adaptation in G. inflata. This study provides the first T2T Glycyrrhiza genome and insights into medicinal compound biosynthesis and environmental adaptation.

Glycyrrhiza↗

Chromosome-level haplotype-resolved genome assembly of the giant honeycomb oyster, Hyotissa hyotis.

The giant honeycomb oyster, Hyotissa hyotis, a common bivalve inhabitant of tropical and subtropical coastal waters, holds significant ecological and economic importance due to its shell characteristics, rapid growth, and high-quality adductor muscle. However, the lack of high-quality genome has impeded the genetic study and artificial breeding of this species. In this study, we provided the first chromosomal-level haplotype-resolved assembly for the H. hyotis (2n = 20) by combining PacBio HiFi long-read and Hi-C sequencing. We obtained a haplotype-resolved assembly of 3.39 Gb in size, of which 96.69% were anchored to 20 chromosomes. The haplotype A and B genome (HapA and HapB) was 1,639.90 and 1,643.23 Mb in size, respectively. Accordingly, a total of 28,720 and 29,003 protein-coding genes were annotated from HapA and HapB. Through the BUSCO evaluation, the assembly and annotation results exhibited the completeness value of 94.65% and 94.03% for HapA, while 94.13% and 92.98% for HapB. This high-quality genome assembly provides valuable resource for further genetic studies and genetic improvement of the group of oysters.

Animals↗

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 chromosomal level genome assembly of Nguni Sheep, Ovis aries.

Nguni sheep (Ovis aries) are indigenous to the Southern Africa region and common within the smallholder and poor resources farming systems. They are well adapted to different agroecological regions. However, limited genomic resources such as high-quality reference genomes have hindered our understanding of its adaptation and establishment of an effective breeding program. To address this, we assembled a chromosomal-level genome of Nguni sheep using a combination of PacBio HiFi reads and Omni-C reads. The genome size was estimated to be 2.9 Gb with a contig/scaffold N50 74 Mb and 99.6 Mb and a genome completeness of 96.1%, as estimated by the Benchmarking Universal Single-Copy Orthologs (BUSCO) program. The final genome encompassed a total of 25,926 protein-coding genes. The findings of this study provide a valuable genomic resource for understanding the adaptability of the Nguni sheep and the establishment of effective breeding programs.

Animals↗

ERGA-BGE chromosome-level genome assembly of the giant stream lacewing  Osmylus fulvicephalus (Scopoli, 1763).

The giant stream lacewing, Osmylus fulvicephalus (Scopoli, 1763), is a widespread European species belonging to the insect order Neuroptera. Its cryptic larvae are predators found at the banks of streams and smaller rivers where they use their piercing, lance-shaped stylets to inject venom into their arthropod prey. Here, we present the reference genome of the giant stream lacewing as a crucial resource for uncovering the genetic basis of venom evolution in Neuroptera. The chromosome-level genome encompasses 674.7 Mb and is composed of 60 contigs and 24 scaffolds where 99.2% of the assembly is distributed among the 6 contiguous chromosomal pseudomolecules and two sex chromosomes (X and Y). Contig and scaffold N50 have a value of 51.5 Mb and 116.2 Mb, respectively. This reference genome is the first genomic resource from the family of lance lacewings, providing valuable data for clarifying the phylogenetic placement of the family Osmylidae within Neuroptera.

Biodiversity Genomics Europe↗

Genome assembly and subgenomic interactions in Brassica napus additional lines with an alien B05 chromosome from B. juncea.

Alien chromosome addition lines hold significant value for breeding and genetic research. However, the genetic interaction between the recipient genome(s) and the alien chromosomes remain largely unclear. Here, we analyzed the genomic composition and gene expression of two purple-leaved B. napus alien addition lines carrying chromosome B05 from B. juncea: the monosomic line ZYCB3 (MAAL, 2n = 39, AACC + 1B05) and the disomic line ZY52 (DAAL, 2n = 40, AACC + 2B05). We assembled a chromosome-level genome of the DAAL ZY52 disomic line and characterized its genomic variation and chromosome introgression patterns. In addition to chromosome B05, multiple introgressed fragments derived from the donor B. juncea line ZYJC were identified, revealing extensive genome remodeling during distant hybridization and backcross breeding. We then used multi-omics approaches to explore chromosomal interactions and the regulation of anthocyanin biosynthesis. Notably, the addition of chromosome B05 was associated with stronger repression of homoeologous genes on C-subgenome chromosomes than on A-subgenome chromosomes. In ZY52, homoeologous genes on chromosome C01 showed reduced expression, whereas in the ZYCB3 monosomic line reduced expression was observed on both C01 and C02. Comparative transcriptomic and metabolomic analyses further showed that highly expressed anthocyanin biosynthesis genes (ABGs) on chromosome B05contributed to anthocyanin accumulation and the purple-leaf phenotype in both addition lines. Overall, this study provides new insights into interchromosomal interactions, genome remodeling, and phenotypic variation in alien addition lines.

Journal Article↗

A telomere-to-telomere reference genome assembly of the red silk cotton tree (Bombax ceiba).

Bombax ceiba, an important ornamental tree and potential fiber resource in the textile industry, is widely distributed in tropical and subtropical regions. In this study, we assembled a nearly gap-free telomere-to-telomere (T2T) genome of B. ceiba using Illumina, PacBio High-fidelity (HiFi), ONT ultra-long, and Hi-C sequencing technologies. The genome spanned approximately 807.89 Mb, with a scaffold N50 of 16.58 Mb, and 754.68 Mb (93.41%) of genomic sequences were anchored onto 48 pseudo-chromosomes. Benchmarking Universal Single-Copy Orthologs (BUSCO) analysis revealed a completeness of 99.40%, identifying 1,378 single-copy and 213 duplicated genes out of 1,614. The genome contained 67.72% (547.11 Mb) repeat regions, with 39,708 predicted protein-coding genes. Collectively, our study provides valuable genomic data for investigating the evolutionary history of the Malvaceae family.

Genome, Plant↗

The First Highly Contiguous Genome Assembly for the Western Bluebird (Sialia mexicana).

The western bluebird (Sialia mexicana) is a secondary cavity-nesting thrush that has experienced historical population declines, local extirpations, and more recent recoveries associated with nest box programs. Despite these regional successes, recent eBird estimates suggest continued range-wide declines and substantial geographic variation in population trajectories, making this species a useful system for future studies of demographic change, connectivity, and conservation genomics. However, genomic resources for western bluebirds remain limited, and no reference genome currently exists for any species in the genus Sialia. Here, we present the first high-quality de novo reference genome for S. mexicana. Using PacBio HiFi long-read sequencing from an adult female, we generated a highly contiguous, phased 1.3 Gb nuclear assembly with a contig N50 of 24.8 Mb and high BUSCO completeness of 98.3%. We annotated the nuclear genome using transcriptomic and protein evidence, identifying 16,656 protein-coding genes and 26,060 transcripts/protein isoforms. We also assembled a complete ∼16 kb mitochondrial genome from Illumina short-read data. This reference genome provides a foundational resource for future studies of population structure, genetic diversity, connectivity, demographic history, and adaptation in western bluebirds and related taxa.

Animals↗