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Long-read transcriptomics corrects Trichomonas vaginalis intron annotations and refines transcript-end features.

BACKGROUND: Trichomonas vaginalis causes the most prevalent non-viral sexually transmitted infection worldwide. Despite its large genome (181.5 Mb; 36,310 predicted protein-coding genes in NYU_TvagG3_2), intron annotations remain limited and inconsistently validated. A recent short-read RNA-seq study reported 63 putative active introns, but short reads can misassign splice boundaries and cannot resolve complete transcript structures. METHODS: We integrated Oxford Nanopore direct RNA sequencing (DRS), ONT cDNA long-read sequencing, and Illumina RNA-seq to refine intron annotations, transcript-end features, and UTR boundaries in T. vaginalis. Candidate introns were validated by targeted PCR and Sanger sequencing, and representative splicing events were further assessed using public SRA datasets. RESULTS: Starting from 31 historically annotated introns, motif-guided long-read screening and orthogonal validation identified 17 additional validated introns, increasing the curated set to 48 confirmed introns. Among these 17 events, three were previously unrecognized in the current NYU_TvagG3_2 reference annotation. We also corrected five reported loci, including two false-positive introns, two splice-coordinate misannotations, and one gene-sequence error. DRS further supported transcript termination site mapping, UAAA polyadenylation-signal profiling relative to poly(A) addition sites, and single-molecule poly(A)-tail estimation. StringTie mixed-mode assemblies provided updated UTR boundaries for intron-bearing transcripts and transcripts without curated introns. CONCLUSIONS: This study provides a rigorously validated, long-read-refined resource of intron annotations, UTR boundaries, and UAAA-guided transcript-end features for T. vaginalis, together with a reproducible workflow for non-model protists. These refinements improve the current reference annotation and support future studies of functional genomics, parasite biology, pathogenesis, and diagnostic development.

Trichomonas vaginalis↗

Comparative genome mapping among Picea glauca, P. mariana x P. rubens and P. abies, and correspondence with other Pinaceae.

A composite linkage map was constructed from four individual maps for the conifer Picea glauca (Moench) Voss, from anonymous and gene-specific markfers (714 AFLPs, 38 SSRs, and 53 ESTPs). A total of 12 linkage groups were delineated with an average marker density of 2.7 cM. Macro-synteny and macro-colinearity comparisons with two other composite linkage maps developed for the species complex P. mariana (Mill.) B.S.P. x P. rubens Sarg., and for P. abies (L.) Karst. revealed an identical number of linkage groups and a remarkable conservation of the gene content and gene order of linkage groups over the million years since the split between these taxa. Identical gene order among taxa was observed for 10 of the 12 assembled composite linkage groups. The discovery of one breakdown in synteny between P. glauca and the other two taxa indicated the occurrence of an inter-chromosomal rearrangement involving an insertional translocation. Analysis of marker colinearity also revealed a putative segmental duplication. The combined information from these three Picea genomes validated and improved large-scale genome comparisons at the inter-generic level in the family Pinaceae by allowing for the identification of 11 homoeologous linkage groups between Picea and Pinus, and nine such groups between Picea and Pseudotsuga menziesii. Notably, the analysis of synteny among the three genera revealed a putative case of chromosomal fission and an inter-chromosomal rearrangement in the genome of P. menziesii. Both of these changes are inter-connected, indicating much instability in this part of the P. menziesii genome. Overall, the macro-structure of the Pinaceae genome was well conserved, which is notable given the Cretaceous origin of its main lineages.

Genome, Plant↗

Separation of near full-length hepatitis C virus quasispecies variants from a complex population.

A long RT-PCR (LRP) protocol was developed recently for robust amplification of a near full-length HCV genomic sequence from clinical samples, followed by efficient cloning [Fan, X., Xu, Y., Di Biceglie, A.M., 2006. Efficient amplification and cloning of near full-length hepatitis C virus genome from clinical samples. Biochem. Biophys. Res. Commun. 346, 1163-1172]. In the present study, the LRP protocol has been estimated for its error rate and the validation by sequencing fully the near full-length HCV inserts from six recombinant clones derived from a patient sample with complex viral diversity. These sequences were compared with the near full-length HCV sequence that was generated by direct sequencing of multiple overlapped PCR products from the same sample, referred to as the population sequence. Comparative analysis confirmed the artificial nature of the PCR-assembled population sequence and identified potential domains for linked viral mutations. The data also suggested that the hypervariable region 1 (HVR1) may be a biological marker for the phenotype at the quasispecies level. These observations emphasize the significance of the use of near full-length genomic sequences for HCV genetic studies and for reverse genetic analysis using authentic quasispecies variants.

Cloning, Molecular↗

Revisiting the genome assembly of Lupinus species reveals differential diploidization after a shared whole-genome duplication.

Accurate genome assemblies are essential for comparative genomics, yet Hi-C-guided scaffolding can introduce structural errors that misrepresent chromosome architecture and bias evolutionary inferences. Here, we identified pervasive scaffolding errors-including artificial fusions, internal inversions, and incomplete contig mounting-in 2 previously published Lupinus genomes (L. cosentinii and L. digitatus) using a segmentation method based on long terminal repeat (LTR) retrotransposon density. We reassembled both genomes, producing chromosome-level references of 472.7 Mb (16 chromosomes) and 427.2 Mb (21 chromosomes), with BUSCO completeness >98.5%. Synteny validation and reapplication of LTR profiling confirmed that all prior errors were resolved. Using these corrected genomes together with 4 additional Lupinus species and 2 outgroup legumes, we investigated postpolyploid evolution. Synonymous substitution rate (Ks) analysis revealed a genus-specific whole-genome duplication (WGD) event (Ks = 0.17) shared by all 6 Lupinus species. The proportion of WGD-derived genes varied markedly, from 60% in L. digitatus to only 36% in L. mutabilis, indicating differential diploidization. While all species retained a core set of WGD duplicates enriched in cytoskeleton organization, ion transport, and defense responses, each exhibited lineage-specific functional trajectories: cell wall modification in L. cosentinii and L. digitatus, nitrogen metabolism in L. albus and L. angustifolius, flower development in L. luteus, and stress/lipid metabolism in L. mutabilis. Our corrected assemblies provide optimal references for Lupinus comparative genomics, and our findings demonstrate that a shared WGD event can lead to both conserved and highly divergent postpolyploid fates, likely underpinning adaptive diversification within the genus.

Lupinus↗

bioWidgets: data interaction components for genomics.

MOTIVATION: The presentation of genomics data in a perspicuous visual format is critical for its rapid interpretation and validation. Relatively few public database developers have the resources to implement sophisticated front-end user interfaces themselves. Accordingly, these developers would benefit from a reusable toolkit of user interface and data visualization components. RESULTS: We have designed the bioWidget toolkit as a set of JavaBean components. It includes a wide array of user interface components and defines an architecture for assembling applications. The toolkit is founded on established software engineering design patterns and principles, including componentry, Model-View-Controller, factored models and schema neutrality. As a proof of concept, we have used the bioWidget toolkit to create three extendible applications: AnnotView, BlastView and AlignView.

Amino Acid Sequence↗

An embedding-based framework enables statistical testing of gene-set function hypotheses inferred by large language models.

Emerging large language models (LLMs) can infer gene functions directly from gene lists, enabling hypothesis generation without predefined gene sets. However, these LLM-derived predictions are qualitative, and principled statistical validation is lacking. Here, we develop an embedding-based statistical framework that transforms gene and function descriptions into vector representations, enabling statistical testing of gene-gene and gene-function relationships and quantitative prioritization of de novo functional hypotheses inferred by LLMs. We benchmark seven state-of-the-art embedding models using curated and retrieval-augmented literature-derived gene descriptions across diverse biological contexts. OpenAI's text-embedding-3-large and Google's gemini-embedding-001 perform best, capturing gene-gene functional relationships in 88.7-92.5% of Gene Ontology biological processes and approximately 98.6% of canonical pathways. In gene-function association analyses, these models achieve high sensitivity (95.2-98.4%) and specificity (72.7-84.3%). Through contamination analysis and evaluation using experimentally informed protein assembly gene sets, our framework distinguishes biologically meaningful LLM-inferred hypotheses from noise, outperforming confidence-based inference and conventional enrichment analysis. We further develop the open-source R package DEGEmbedR and demonstrate its utility for interpreting a drug perturbation-derived differentially expressed gene (DEG) signature lacking significant conventional enrichment results. Together, these results establish LLM-derived embeddings as a quantitative foundation for functional genomics and the statistical validation of LLM-based gene function inference.

Large Language Models↗

Multiple-complete-digest restriction fragment mapping: generating sequence-ready maps for large-scale DNA sequencing.

Multiple-complete-digest mapping is a DNA mapping technique based on complete-restriction-digest fingerprints of a set of clones that provides highly redundant coverage of the mapping target. The maps assembled from these fingerprints order both the clones and the restriction fragments. Maps are coordinated across three enzymes in the examples presented. Starting with yeast artificial chromosome contigs from the 7q31.3 and 7p14 regions of the human genome, we have produced cosmid-based maps spanning more than one million base pairs. Each yeast artificial chromosome is first subcloned into cosmids at a redundancy of x15-30. Complete-digest fragments are electrophoresed on agarose gels, poststained, and imaged on a fluorescent scanner. Aberrant clones that are not representative of the underlying genome are rejected in the map construction process. Almost every restriction fragment is ordered, allowing selection of minimal tiling paths with clone-to-clone overlaps of only a few thousand base pairs. These maps demonstrate the practicality of applying the experimental and software-based steps in multiple-complete-digest mapping to a target of significant size and complexity. We present evidence that the maps are sufficiently accurate to validate both the clones selected for sequencing and the sequence assemblies obtained once these clones have been sequenced by a "shotgun" method.

Base Composition↗

A bacterial artificial chromosome based physical map of the Ustilago maydis genome.

Ustilago maydis, a basidiomycete, is a model organism among phytopathogenic fungi. A physical map of U. maydis strain 521 was developed from bacterial artificial chromosome (BAC) clones. BAC fingerprints used polyacrylamide gel electrophoresis to separate restriction fragments. Fragments were labeled at the HindIII site and co-digested with HaeIII to reduce fragments to 50-750 bp. Contiguous overlapping sets of clones (contigs) were assembled at nine stringencies (from P < or = 1 x 10(-6) to 1 x 10(-24)). Each assembly nucleated contigs with different percentages of bands overlapping between clones (from 20% to 97%). The number of clones per contig decreased linearly from 41 to 12 from P < or = 1 x 10(-7) to 1 x 10 (-12). The number of separate contigs increased from 56 to 150 over the same range. A hybridization-based physical map of the same BAC clones was compared with the fingerprint contigs built at P < or = 1 x 10(-7). The two methods provided consistent physical maps that were largely validated by genome sequence. The combined hybridization and fingerprint physical map provided a minimum tile path composed of 258 BAC clones (18-20 Mbp) distributed among 28 merged contigs. The genome of U. maydis was estimated to be 20.5 Mbp by pulsed-field gel electrophoresis and 24 Mbp by BAC fingerprints. There were 23 separate chromosomes inferred by both pulsed-field gel electrophoresis and fingerprint contigs. Only 11 of the tile path BAC clones contained recognizable centromere, telomere, and subtelomere repeats (high-copy DNA), suggesting that repeats caused some false merges. There were 247 tile path BAC clones that encompassed about 17.5 Mbp of low-copy DNA sequence. BAC clones are available for repeat and unique gene cluster analysis including tDNA-mediated transformation. Program FingerPrint Contigs maps aligned with each chromosome can be viewed at http://www.siu.edu/~meksem/ustilago_maydis/.

Chromosomes, Artificial, Bacterial↗

De novo transcriptome assembly and gene expression analysis of Cnidium officinale under high-temperature conditions.

BACKGROUND: The medicinal plant Cnidium officinale (CO) is widespread in Northeast Asia and vulnerable to heat stress. The naturally occurring composition of pharmacological ingredients of CO results in overall physiological consequences; therefore, it is crucial to have a comprehensive understanding of metabolic response to ambient heat in terms of acclimation to estimate how much CO is exposed to threatening environmental conditions. RESULTS: Transcriptome analysis is critical for understanding the consequences of long-term physiological adaptation of CO to abiotic stress. However, transcriptome analysis on this species, particularly under prolonged stress conditions, has remained limited. We employed a temperature gradient tunnel (TGT) to subject CO to high-temperature exposure for four months, enabling us to observe the cumulative effects of heat and assess its acclimation mechanisms. In the absence of genome sequencing data, we performed de novo transcriptome assembly and compared DEGs from temperature treatment plots of a TGT and a growth chamber (GC). Since interpreting transcriptomic data can be complex, we employed a sequential analytical approach, including DEG clustering, GO enrichment, KEGG pathway mapping, miRNA-target gene analysis, and multiple rounds of RNA sequencing validation. DEGs were classified into two categories: genes exhibiting significant fold changes and genes showing significant count changes rather than fold changes. Then, we analyzed the functional roles&#xa0;of DEGs to determine which pathways respond to ambient and stressful high temperatures and validated the findings through cross-comparison with GC. Additionally, we conducted miRNA analysis to investigate post-transcriptional regulation under high temperatures. CO grown under higher ambient temperatures exhibited slight upregulation of pathways related to protein stability and turnover, ABA biosynthesis, and energy production, such as photosynthesis and oxidative phosphorylation. However, under extreme heat stress, most metabolic pathways were downregulated except for those involved in transcription, translation, oxidative phosphorylation and the biosynthesis of cutin, suberin, and wax. CONCLUSION: This study demonstrated that proper clustering of genes based on expression levels and fold changes in two different experimental conditions, along with pathway mapping, may provide a comprehensive understanding of CO's response to heat stress. These insights could contribute to future research on heat tolerance and crop improvement.

Gene Expression Profiling↗

A tryptophan-rich hexapeptide inhibits nucleic acid destabilization chaperoned by the HIV-1 nucleocapsid protein.

The nucleocapsid protein (NC) of HIV-1 exerts critical functions in viral genome replication and virus assembly. Since the recognition of target nucleic acids is required in the initial step of most NC-mediated processes, attempts were made to find small molecules capable of competing with this recognition. In particular, several Trp-rich hexapeptides were recently found to strongly bind RNA sequences targeted by NC. To further validate these peptides as potential anti-NC agents, we studied the ability of Ac-HKWPWW-NH2, taken as a representative, to interfere with the NC chaperone properties required during reverse transcription. Using NMR and steady-state and time-resolved fluorescence spectroscopy, we characterized the structure of Ac-HKWPWW-NH2 as well as its binding to viral sequences such as TAR and PBS involved in the two obligatory strand transfers of reverse transcription. Results show that Ac-HKWPWW-NH2 exhibits an almost symmetric cis-trans equilibrium at the level of the Pro residue where it is structured. The peptide binds both TAR and PBS sequences with low micromolar affinities. The cis-Pro and trans-Pro conformations of the peptide bind with comparable affinities to (-)PBS, mainly through stacking interactions between the Trp residues and the (-)PBS bases. Though all three Trp residues may contribute to the (-)PBS/Ac-HKWPWW-NH2 complex formation, Trp3 and Trp5 residues are the key residues in the complexes with the cis-Pro and trans-Pro conformations, respectively. Moreover, Ac-HKWPWW-NH2 stabilizes cTAR secondary structure and largely inhibits the NC-directed melting of cTAR. This further strengthens the interest of this peptide for deriving modified peptides capable of inhibiting NC and HIV-1 replication.

Amino Acid Sequence↗

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&#x2009;Gb, perfectly matching the haploid chromosome number with a contig N50 of 46.17&#x2009;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↗

Construction and application of a full-coverage, high-resolution, human chromosome 8q genomic microarray for comparative genomic hybridization.

BACKGROUND: Array-based comparative genomic hybridization (aCGH) enables genome-wide quantitative delineation of genomic imbalances. A high-resolution contig array was developed specifically for chromosome 8q because this chromosome arm is frequently altered in many human cancers. METHODS: A minimal tiling path contig of 702 8q-specific bacterial artificial chromosome (BAC) clones was generated with a novel computational tool (BAC Contig Assembler). BAC clones were amplified by degenerative oligonucleotide primer (DOP) polymerase chain reaction and subsequently printed onto glass slides. For validation of the array DNA samples of gastroesophageal and prostate cancer cell lines, and chronic myeloid leukemia specimens were used, which were previously characterized by multicolor fluorescence in situ hybridization and conventional CGH. RESULTS: Single and double copy gains were confidently demonstrated with the 8q array. Single copy loss and high-level amplifications were accurately detected and confirmed by bicolor fluorescence in situ hybridization experiments. The 8q array was further tested with paraffin-embedded prostate cancer specimens. In these archival specimens, the copy number changes were confirmed. In fresh and archival samples, additional alterations were disclosed. In comparison with conventional CGH, the resolution of the detected changes was much improved, which was demonstrated by an amplicon of 0.7 Mb and a deletion of 0.6 Mb, both spanned by only six BAC clones. CONCLUSIONS: A comprehensive array is presented, which provides a high-resolution method for mapping copy number alterations on chromosome 8q.

Adenocarcinoma↗

Raman markers of nonaromatic side chains in an alpha-helix assembly: Ala, Asp, Glu, Gly, Ile, Leu, Lys, Ser, and Val residues of phage fd subunits.

The study of filamentous virus structure by Raman spectroscopy requires accurate band assignments. In previous work, site- and residue-specific isotope substitutions were implemented to elucidate definitive assignments for Raman bands arising from vibrational modes of the alpha-helical coat protein main chain and aromatic side chains in the class I filamentous phage, fd [Overman, S. A., and Thomas, G. J., Jr. (1995) Biochemistry 34, 5440-5451; Overman, S. A., and Thomas, G. J., Jr. (1998) Biochemistry 37, 5654-5665]. Here, we extend the previous methods and expand the assignment scheme to identify Raman markers of nonaromatic side chains of the coat protein in the native fd assembly. This has been accomplished by Raman analysis of 11 different fd isotopomers selectively incorporating deuterium at specific sites in either alanine, aspartic acid, glutamic acid, glycine, isoleucine, leucine, lysine, serine, or valine residues of the coat protein. Raman markers are also identified for the corresponding deuterated side chains. In combination with previous assignments, the results provide a comprehensive understanding of coat protein contributions to the Raman signature of the fd virion and validate Raman markers assigned to the packaged single-stranded DNA genome. The findings described here show that nonaromatic side chains contribute prolifically to the fd Raman signature, that marker bands for specific nonaromatics differ in general from those observed in corresponding polypeptides and amino acids, and that the frequencies and intensities of many nonaromatic markers are sensitive to secondary and higher-order structures. Nonaromatic markers within the 1200-1400 cm-1 interval also interfere seriously with the diagnostic Raman amide III band that is normally exploited in secondary structure analysis. Implications of these findings for the assessment of protein conformation by Raman spectroscopy are considered.

Alanine↗

The design of drug candidate molecules as selective inhibitors of therapeutically relevant protein kinases.

The human genome encompasses some 2,000 proteins that utilize adenosine 5'-triphosphate (ATP) in one way or another and some 500 of these are protein-tyrosine and protein-serine/threonine kinases (PTKs & PSTKs). Substrate phosphorylation by these enzymes is nature's predominant molecular way of organizing cellular signal transduction and regulating biochemical processes in general. It is not surprising, therefore, that abnormal phosphorylation of cellular proteins is a hallmark of disease and that there has been a growing interest in the use of kinase inhibitors as drugs. In fact the search for such agents has recently culminated in the approval of the first kinase inhibitor drugs for medical use. Although it has been demonstrated exhaustively that potent and structurally diverse ATP-antagonistic small molecule kinase inhibitors can be found through mass screening and structure-guided design, the question of biochemical, cellular, and in vivo selectivity of such inhibitors remains much less clear. Here the medicinal chemistry of kinase inhibitors is reviewed critically with particular emphasis on target selectivity and specificity. Approaches based on chemical genomics, combinatorial target-guided ligand assembly, computational chemistry, and structural biology techniques, which aim at classifying both inhibitors and kinase targets, are given special emphasis. The various strategies in which differences in biochemical mechanism of kinase function can be exploited in order to attain selective inhibition are also discussed. Furthermore, recent developments in the design of inhibitors to selected individual validated therapeutic kinase targets, including cell cycle kinases and receptor PTKs, etc. are summarised.

Antineoplastic Agents↗

Comparative performance of portable DNA extraction protocols and bioinformatics workflows for rapid detection of gram-negative bacteria and antimicrobial resistance using Oxford Nanopore sequencing.

Oxford Nanopore Technology (ONT) enables rapid, portable pathogen identification and antimicrobial resistance (AMR) detection, but the reliability of downstream genomic analyses is highly dependent on DNA extraction quality, particularly in resource-limited settings. This study comparatively evaluated four portable bacterial DNA extraction protocols derived from three commercial kits to determine their impact on nanopore sequencing performance, bioinformatics workflow completion, and field deployability. Six gram-negative bacterial isolates (Escherichia coli, n = 4; Pseudomonas sp., n = 1; and Salmonella sp., n = 1) were processed using four extraction protocols: SwiftX DNA, SwiftX DNA with proteinase K (ProtK), SwiftX ParaBact, and NucleoSpin Microbial. Twenty-four resulting DNA extracts were sequenced on a single multiplexed MinION R10.4.1 flow cell. Sequencing data were analyzed using validated Galaxy-based generic and species-specific pipelines. Workflow completion was defined as successful progression through quality control, assembly, virulence, plasmid, and AMR detection modules. DNA purity varied substantially by extraction protocol and was strongly associated with successful workflow completion (Kruskal-Wallis, P = 0.0006). Accordingly, NucleoSpin Microbial achieved 100% workflow completion, and SwiftX ParaBact achieved 83%, while both SwiftX DNA-based protocols failed to complete full workflows. Importantly, key AMR genes required to classify isolates as multidrug-resistant were consistently detected using both NucleoSpin Microbial and SwiftX ParaBact extractions. However, NucleoSpin Microbial assemblies showed significantly higher contiguity and enabled a broader, more complete detection of virulence factors, pathogenicity islands, plasmid replicons, and accessory AMR genes, reflecting enhanced genomic resolution.IMPORTANCERapid whole-genome sequencing is increasingly used to detect antimicrobial resistance and guide public health responses, but its reliability depends strongly on how bacterial DNA is extracted. In this study, we have shown that DNA extraction method choice has a major impact on Oxford Nanopore sequencing performance across clinically relevant gram-negative bacteria. While silica column-based extraction maximized genomic completeness and analytical depth, paramagnetic bead-based reverse purification offered superior portability with sufficient resolution for frontline AMR surveillance. These findings highlight a practical trade-off between field deployability and high-resolution genomic characterization in low-resource settings.

DNA extraction↗

Heterokairic Genes and the Eco-Evo-Devo of Timing.

Concepts of developmental timing have traditionally been framed under heterochrony as evolved (genetically based) differences in timing, while environmentally induced shifts in timing within genotypes have been treated more loosely. In this article, heterokairy is presented as plasticity in the timing of developmental events, and the term "heterokairic genes" is proposed for environmentally modulated heterochronic genes that underlie this plasticity. Evidence from nematodes, insects, plants, and vertebrates is assembled, with emphasis placed on systems where environmental cues are relayed through endocrine or metabolic pathways to known timing modules/genes. On this basis, a distinction is drawn between validated heterokairic genes, supported by direct mechanistic data, and a broader set of candidates inferred from gene-environment interactions in developmental timing. The eco-evolutionary consequences of such genes are considered, and experimental and genomic strategies for their identification are outlined. It is argued that heterokairic genes provide a useful bridge between environmental variation, developmental mechanisms, and evolutionary change in timing.

Animals↗

DNA sequence determination by hybridization: a strategy for efficient large-scale sequencing.

The concept of sequencing by hybridization (SBH) makes use of an array of all possible n-nucleotide oligomers (n-mers) to identify n-mers present in an unknown DNA sequence. Computational approaches can then be used to assemble the complete sequence. As a validation of this concept, the sequences of three DNA fragments, 343 base pairs in length, were determined with octamer oligonucleotides. Possible applications of SBH include physical mapping (ordering) of overlapping DNA clones, sequence checking, DNA fingerprinting comparisons of normal and disease-causing genes, and the identification of DNA fragments with particular sequence motifs in complementary DNA and genomic libraries. The SBH techniques may accelerate the mapping and sequencing phases of the human genome project.

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↗