Search Results (134)

Background/Objectives: The 3-dimensional (3D) architecture of the genome in the nucleus of a living cell plays an unexpected yet fundamental regulatory role in cell biology. As an imprint of the cellular genetic, epigenetic and metabolic status, it discriminates pathological conditions through conditional changes to long-range 3D interactions (up to 300 kb) and thus could act as a powerful molecular biomarker linked closely to clinical outcomes. Methods: Here an assessment is made of the latest paradigm shift in molecular biology from a supply chain where information flows from DNA to RNA to protein, to the concept of heritable 3D folding of the genome reflecting the epigenetic and metabolic state of the cell, and which serves as a molecular biomarker for complex clinical outcome. Results: While biomarkers based on individual components of the supply chain fail to accurately reflect clinical outcomes, 3D genomics offers highly informative insights, exemplified for immuno-oncology and prostate cancer diagnosis by clinical tests of superior performance, already in practice in the US and UK. Conclusions: A more complete understanding of human biology will require models that account for the flow of information to and from the 3D genomic architecture in living cells, together with its regulation and logic. Integrating these principles into biomarker discovery and therapeutic design, along with other frontline approaches in precision medicine, including multi-omics and other system-level tools, will be essential for advancing precision medicine beyond its current limitations. Full article

The yellow flower lotus (Nelumbo lutea) is the sister species of the sacred lotus (N. nucifera). The evolution of gene expression patterns across multiple tissues during the species divergence of these two lotuses remains unexplored. The WUSCHEL-related homeobox (WOX) family, a plant-specific transcription factor family, plays a crucial role in tissue development and stress responses. In this study, utilizing a chromosome-level reference genome and a transcriptome database covering multiple tissues, we identified and categorized 11 NlWOX genes into three subfamilies. We identified seven syntenic gene pairs between NnWOXs and NlWOXs that originated from whole-genome duplications. Through conserved motif analysis, we found subfamily-specific motifs in the protein sequences of NnWOXs and NlWOXs. Variations in the three-dimensional conformations of homologous WOX genes indicate function divergences between the two lotus species. The gene expression matrix of NlWOX across tissues reveals expression divergences within N. lutea and between the two lotus species. By employing a weight gene co-expression network analysis pipeline, we developed eight NlWOX co-expression networks that differed from the co-expression networks of their syntenic genes. Overall, our findings suggest that genomic variations in the WOX orthologs contribute to the distinct expression patterns and regulatory networks observed during the evolution of these two lotuses. Full article

Background: Cashmere is one of the important economic products of goats, and the KRTAP gene family, as an important family of regulatory genes in the growth process of cashmere fiber, largely affects the quality of cashmere. Methods: In this study, the KRTAP6-3 gene was identified and located on goat chromosome 1 using a goat genome homology search combined with a phylogenetic tree approach. The Longdong cashmere goat KRTAP6-3 gene variation and its effect on cashmere quality were explored by using the polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP) technique, in situ hybridization, and the allele presence/absence model. Results: The results identified a total of six SNPs in KRTAP6-3, three of which were located in the coding region and two of which were synonymous mutations, in addition to 45- bp deletion sequences detected in alleles C and F. Moreover, the KRTAP6-3 mRNA showed a strong expression signal in the cortical layer of the primary and secondary follicles in the inner root sheaths, as well as in the cells of the hair papillae and the matrices during the anagen phase, and signaling at the sites described above is attenuated during the telogen phase. The presence of allele C was associated with increased MFD (mean fiber diameter) (p < 0.01). The MFD of goats with allele C genotype (genotype AC) was significantly higher (p < 0.05) than that of goats without allele C genotype (genotypes AA and AB). Conclusions: This indicates that genetic variation in the KRTAP6-3 gene in goats is significantly associated with cashmere traits and can serve as a candidate gene for molecular markers of cashmere traits. Full article

Background: The German Black Pied Dairy (DSN) cattle is an endangered dual-purpose breed considered an ancestor of the modern Holstein population. DSN is known for its high milk yield, favorable milk composition, and good meat quality. Maintaining a functional body structure is essential for ensuring sustained performance across multiple lactations in dual-purpose breeds like DSN. This study aims to identify candidate genes and genetic regions associated with conformation traits in DSN cattle through genome-wide association studies (GWAS). Methods: The analysis utilized imputed whole-genome sequencing data of 1852 DSN cows with conformation data for 19 linear traits and four composite scores derived from these traits. GWAS was performed using linear mixed models. Results: In total, we identified 118 sequence variants distributed across 24 quantitative trait locus (QTL) regions comprising 74 positional candidate genes. Among the most significant findings were variants associated with “Rump width” on chromosome 21 and “Teat length” on chromosome 22, with AGBL1 and SRGAP3 identified as the most likely candidate genes. Additionally, a QTL region on chromosome 15 linked to “Central ligament” contained 39 olfactory receptor genes, and a QTL region on chromosome 23 associated with “Hock quality” included eight immune-related genes, notably, BOLA and TRIM family members. Conclusions: Selective breeding for favorable alleles of the investigated conformation traits may contribute to DSN’s longevity, robustness, and overall resilience. Hence, continuous focus on healthy udders, feet, and legs in herd management contributes to preserving DSN’s positive traits while improving conformation. Full article

Genome-editing technology has advanced significantly since the 2020 Nobel Prize in Chemistry was awarded for the development of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9). While CRISPR–Cas9 has become widely used in academic research, its social implementation has lagged due to unresolved patent disputes and slower progress in gene function analysis. To address this, new approaches bypassing direct gene function analysis are needed, with bioinformatics and next-generation sequencing (NGS) playing crucial roles. NGS is essential for sequencing the genome of target species, but challenges such as data quality, genome heterogeneity, ploidy, and small individual sizes persist. Despite these issues, advancements in sequencing technologies, like PacBio high-fidelity (HiFi) long reads and high-throughput chromosome conformation capture (Hi-C), have improved genome sequencing. Bioinformatics contributes to genome editing through off-target prediction and target gene selection, both of which require accurate genome sequence information. In this review, I will give updates on the development of genome editing and bioinformatics technologies with a focus on the rapid progress in genome sequencing. Full article

Avermectin is a widely used insecticide for pest control, such as the Plutella xylostella. Despite its efficacy in pest management, concerns have been raised regarding its effect on non-target species, such as the important economic insect silkworm (Bombyx mori). We aimed to investigate the effects of avermectin application on the 3D genome architecture of silkworm midgut using high-throughput techniques such as high-throughput chromosome conformation capture (Hi-C) coupled with RNA sequencing (RNA-seq) and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq). Midgut tissue samples, during the fifth instar and three days, were collected from silkworm larvae fed mulberry leaves (control group) and leaves soaked in avermectin solution for 12 h (experimental group). Our findings revealed that avermectin treatment led to significant changes, including 386 differentially expressed genes (252 up-regulated, 134 down-regulated) and increased chromatin accessibility, particularly those involved in immune response, metabolism, and cellular stress pathways. The Hi-C data revealed more intense spatial interactions in the experimental group, leading to increased expression of detoxification proteins like ABC transporter. This study provides important insights into the molecular basis of pesticide resistance and a foundational basis for further research on the genetic and epigenetic mechanisms of insect stress responses. Full article

The 3D organization of chromatin in the nucleus plays a critical role in regulating gene expression and maintaining cellular functions in eukaryotic cells. High-throughput chromosome conformation capture (Hi-C) and its derivative technologies have been developed to map genome-wide chromatin interactions at the population and single-cell levels. However, insufficient sequencing depth and high noise levels in bulk Hi-C data, particularly in single-cell Hi-C (scHi-C) data, result in low-resolution contact matrices, thereby limiting diverse downstream computational analyses in identifying complex chromosomal organizations. To address these challenges, we developed a transformer-based deep learning model, HiCENT, to impute and enhance both scHi-C and Hi-C contact matrices. Validation experiments on large-scale bulk Hi-C and scHi-C datasets demonstrated that HiCENT achieves superior enhancement effects compared to five popular methods. When applied to real Hi-C data from the GM12878 cell line, HiCENT effectively enhanced 3D structural features at the scales of topologically associated domains and chromosomal loops. Furthermore, when applied to scHi-C data from five human cell lines, it significantly improved clustering performance, outperforming five widely used methods. The adaptability of HiCENT across different datasets and its capacity to improve the quality of chromatin interaction data will facilitate diverse downstream computational analyses in 3D genome research, single-cell studies and other large-scale omics investigations. Full article

Individual cells and cells within the tissues and organs constantly face mechanical challenges, such as tension, compression, strain, shear stress, and the rigidity of cellular and extracellular surroundings. Besides the external mechanical forces, cells and their components are also subjected to intracellular mechanical forces, such as pulling, pushing, and stretching, created by the sophisticated force-generation machinery of the cytoskeleton and molecular motors. All these mechanical stressors switch on the mechanotransduction pathways, allowing cells and their components to respond and adapt. Mechanical force-induced changes at the cell membrane and cytoskeleton are also transmitted to the nucleus and its nucleoskeleton, affecting nucleocytoplasmic transport, chromatin conformation, transcriptional activity, replication, and genome, which, in turn, orchestrate cellular mechanical behavior. The memory of mechanoresponses is stored as epigenetic and chromatin structure modifications. The mechanical state of the cell in response to the acellular and cellular environment also determines cell identity, fate, and immune response to invading pathogens. Here, we give a short overview of the latest developments in understanding these processes, emphasizing their effects on cell nuclei, chromosomes, and chromatin. Full article

Circular bacteriocins are potent antimicrobials against pathogenic Gram-positives. In searching for marine bacteriocins, an antibacterial peptide (flexusin A) was purified from the fermentation broth of marine bacterium Bacillus flexus R29-2. Genome sequencing and gene annotation revealed the chromosome contained an unknown circular bacteriocin gene cluster. Approaches including shot-gun proteomics analysis, AntiSMASH and BAGEL4 predication as well as the comprehensive sequence alignment, were then conducted, respectively, to verify the correlation of flexusin A with the gene-encoded precursor peptide. The results confirmed that flexusin A was the mature circular bacteriocin of the predicated precursor peptide with six amino acids as leader peptide. Flexusin A was 6098.4 Da in size, with a net charge of +3 and PI of 9.60. It shared the typical saposin-like fold spatial conformation features as commonly found in other circular bacteriocins. Flexusin A was pH, thermal, and protease tolerant. It exhibited a narrow antimicrobial spectrum against Gram-positives, and it can strongly inhibit Staphylococcus aureus by causing cell destruction via membrane destabilization. Taken together, a novel circular bacteriocin flexusin A was identified in this work. The characterization of flexusin A has extended circular bacteriocins family to 26 members. This is also the first report on bacteriocin production by B. flexus. Full article

G-quadruplexes (G4s) are unique nucleic acid structures composed of guanine-rich (G-rich) sequences that can form diverse topologies based on the arrangement of their four strands. G4s have attracted attention for their potential roles in various biological processes and human diseases. In this review, we focus on the G4 structures formed by human telomeric sequences, (GGGTTA)_n, and the hexanucleotide repeat expansion, (GGGGCC)_n, in the first intron region of the chromosome 9 open reading frame 72 (C9orf72) gene, highlighting their structural diversity and biological significance. Human telomeric G4s play crucial roles in telomere retention and gene regulation. In particular, we provide an in-depth summary of known telomeric G4s and focus on our recently discovered chair-type conformation, which exhibits distinct folding patterns. The chair-type G4s represent a novel folding pattern with unique characteristics, expanding our knowledge of telomeric G4 structural diversity and potential biological functions. Specifically, we emphasize the G4s formed by the (GGGGCC)_n sequence of the C9orf72 gene, which represents the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The thorough structural analysis in this review advances our comprehension of the disease mechanism and provides valuable insights into developing targeted therapeutic strategies in ALS/FTD. Full article

Background/Objectives: Colorectal cancer (CRC) arises from the epithelial lining of the colon or rectum, often following a progression from benign adenomatous polyps to malignant carcinoma. Screening modalities such as colonoscopy, faecal immunochemical tests (FIT), and FIT-DNA are critical for early detection and prevention, but non-invasive methods lack sensitivity to polyps and early CRC. Chromosome conformations (CCs) are potent epigenetic regulators of gene expression. We have previously developed an epigenetic assay, EpiSwitch^®®, that employs an algorithmic-based CCs analysis. Using EpiSwitch^®® technology, we have shown the presence of cancer-specific CCs in peripheral blood mononuclear cells (PBMCs) and primary tumours of patients with melanoma and prostate cancer. EpiSwitch^®®-based commercial tests are now available to diagnose prostate cancer with 94% accuracy (PSE test) and response to immune checkpoint inhibitors across 14 cancers with 85% accuracy (CiRT test). Methods/Results/Conclusions: Using blood samples collected from n = 171 patients with CRC, n = 44 patients with colorectal polyps and n = 110 patients with a ‘clear’ colonoscopy we performed whole Genome DNA screening for CCs correlating to CRC diagnosis. Our findings suggest the presence of two eight-marker CC signatures (EpiSwitch^®® NST) in whole blood that allow diagnosis of CRC and precancerous polyps, respectively. Independent validation cohort testing demonstrated high accuracy in identifying colorectal polyps and early versus late stages of CRC with an exceptionally high sensitivity of 79–90% and a high positive prediction value of 60–84%. Linking the top diagnostic CCs to nearby genes, we have built pathways maps that likely underline processes contributing to the pathology of polyp and CRC progression, including TGFβ, cMYC, Rho GTPase, ROS, TNFa/NFκB, and APC. Full article

(1) Background: Chitons (Mollusca, Polyplacophora) are relatively primitive species in Mollusca that allow the study of biomineralization. Although mitochondrial genomes have been isolated from Polyplacophora, there is no genomic information at the chromosomal level; (2) Methods: Here we report a chromosome-level genome assembly for Acanthochiton rubrolineatus using PacBio (Pacific Biosciences, United States) reads and high-throughput chromosome conformation capture (Hi-C) data; (3) Results: The assembly spans 1.08 Gb with a contig N50 of 3.63 Mb and 99.97% of the genome assigned to eight chromosomes. Among the 32,291 predicted genes, 76.32% had functional predictions. The divergence time of Brachiopoda and Mollusca was ~550.8 Mya (million years ago), and that of A. rubrolineatus and other mollusks was ~548.5 Mya; (4) Conclusions: This study not only offers high-quality reference sequences for the Acanthochiton rubrolineatus genome, but also establishes groundwork for investigating the mechanisms of Polyplacophora biomineralization and its evolutionary history. This research will aid in uncovering the genetic foundations of molluscan adaptations across diverse environments. Full article

The genus Ilex belongs to the sole family and is the single genus within the order Aquifoliales, exhibiting significant phenotypic diversity. However, the genetic differences underlying these phenotypic variations have rarely been studied. In this study, collinearity analyses of three Ilex genomes, Ilex latifolia Thunb., Ilex polyneura (Hand.-Mazz.) S. Y. Hu, and Ilex asprella Champ. ex Benth., indicated a recent fusion event contributing to the reduction of chromosomes in I. asprella. Comparative genome analyses showed slight differences in gene annotation among the three species, implying a minimal disruption of genes following chromosomal fusion in I. asprella. Comprehensive annotation of transposable elements (TEs) revealed that TEs constitute a significant portion of the Ilex genomes, with LTR transposons being predominant. TEs exhibited an inverse relationship with gene density, potentially influencing gene regulation and chromosomal architecture. TE insertions were shown to affect the conformation and binding sites of key genes such as 7-deoxyloganetin glucosyltransferase and transmembrane kinase (TMK) genes, highlighting potential functional impacts. The structural variations caused by TE insertions suggest significant roles in the evolutionary dynamics, leading to either loss or gain of gene function. This study underscores the importance of TEs in shaping the genomic landscape and evolutionary trajectories of Ilex species. Full article

The linear conformation of animals exerts an influence on health, reproduction, production, and welfare, in addition to longevity, which directly affects the profitability of milk-producing farms. The objectives of this study were (1) to perform genome-wide association studies (GWASs) of conformation traits, namely the Rump, Feet and Legs, Mammary System, Dairy Strength, and Final Classification traits, and (2) to identify genes and related pathways involved in physiological processes associated with conformation traits in Brazilian Holstein cattle. Phenotypic and genotypic data from 2339 Holstein animals distributed across the states of Rio Grande do Sul, Paraná, São Paulo, and Minas Gerais were used. The genotypic data were obtained with a 100 K SNP marker panel. The single-step genome-wide association study (ssGWAS) method was employed in the analyses. Genes close to a significant SNP were identified in an interval of 100 kb up- and downstream using the Ensembl database available in the BioMart tool. The DAVID database was used to identify the main metabolic pathways and the STRING program was employed to create the gene regulatory network. In total, 36 significant SNPs were found on 15 chromosomes; 27 of these SNPs were linked to genes that may influence the traits studied. Fourteen genes most closely related to the studied traits were identified, as well as four genes that showed interactions in important metabolic pathways such as myogenesis, adipogenesis, and angiogenesis. Among the total genes, four were associated with myogenesis (TMOD2, TMOD3, CCND2, and CTBP2), three with angiogenesis (FGF23, FGF1, and SCG3), and four with adipogenesis and body size and development (C5H12orf4, CCND2, EMILIN1, and FGF6). These results contribute to a better understanding of the biological mechanisms underlying phenotypic variability in conformation traits in Brazilian Holstein cattle. Full article

KMT2A (alias: mixed-lineage leukemia [MLL]) gene mapping on chromosome 11q23 encodes the lysine-specific histone N-methyltransferase 2A and promotes transcription by inducing an open chromatin conformation. Numerous genomic breakpoints within the KMT2A gene have been reported in young children and adults with hematologic disorders and are present in up to 10% of acute leukemias. These rearrangements describe distinct features and worse prognosis depending on the fusion partner, characterized by chemotherapy resistance and high rates of relapse, with a progression-free survival of 30–40% and overall survival below 25%. Less intensive regimens are used in pediatric patients, while new combination therapies and targeted immunotherapeutic agents are being explored in adults. Beneficial therapeutic effects, and even cure, can be reached with hematopoietic stem cell transplantation, mainly in young children with dismal molecular lesions; however, delayed related toxicities represent a concern. Herein, we summarize the translocation partner genes and partial tandem duplications of the KMT2A gene, their molecular impact, clinical aspects, and novel targeted therapies. Full article