Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “genome streamlining”

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.

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

At least 73 records · Page 4Linked to original sources

An inducer-independent, single-plasmid CRISPR-Cas9 system for genome editing in Bacillus species.

Advances in molecular biology tools are essential for streamlining and accelerating genetic engineering of cells across industrial and academic applications. While CRISPR-Cas improves genome editing efficiency, current systems have limitations and are often host specific, which restricts their versatility. This study describes a versatile CRISPR-Cas9 system for genome editing in industrially relevant Bacillus species. By adapting the well-established pJOE8999 vector-based CRISPR-Cas9 genome editing system, we constructed an inducer-independent, broad-host-range genome editing system. It maintains the benefits of low toxicity to the target cell and the cloning host as well as the ease to use of a single-plasmid CRISPR-Cas9 system. We utilized the constitutive Sigma70-type promoter from the conserved veg gene of Bacillus, to develop and test the suitability of promoter variants of different strengths for Cas9 expression. Successful gene deletions in three different Bacillus species demonstrated the versatility of the modified system for this industrially important genus. This was further confirmed by the integration of a reporter gene fusion and the introduction of a single point mutation in the genome of Bacillus licheniformis. This one-step CRISPR-based transformation protocol developed in this study enables fast genome editing workflows with minimal hands-on time. KEY POINTS: • Editing and screening of promoter variants for balanced Cas9 expression in Bacillus. • Development of a versatile inducer-independent, single-plasmid CRISPR-Cas-based system. • Verification of the modified CRISPR-based system for genome editing in different Bacilli.

CRISPR-Cas Systems↗

Prenatal origin of TEL-AML1-positive acute lymphoblastic leukemia in children born in California.

Acute lymphoblastic leukemia (ALL) is the most common form of childhood cancer. The peak incidence of ALL between ages 2 and 5 is accounted for by one subtype, referred to as common acute lymphoblastic leukemia (cALL). About 25% of cALL patients have the TEL-AML1 gene fusion derived from the t(12;21) chromosomal translocation. Recent evidence from retrospective analysis of neonatal blood spots (Guthrie cards) in Europe has demonstrated that this chromosome translocation may arise prenatally. The aim of our study was to determine whether TEL-AML1 fusions arise prenatally in a U.S. population of cALL patients. TEL-AML1-positive cALL cases (n = 14) were identified by fluorescence in situ hybridization, and the genomic breakpoints were identified by a streamlined long-distance PCR approach and sequenced. Clonotypic primers were designed for each patient breakpoint, and a nested PCR assay was used to determine the presence of the TEL-AML1 fusion sequence in neonatal Guthrie cards. Seven of 14 cases demonstrated clonotypic sequences on the archival Guthrie cards. The oldest patient that was positive was 6.7 years old at the time of diagnosis of leukemia. These results confirm previously published findings of a prenatal origin of TEL-AML1 in Europe by demonstrating its occurrence in a California-born population. Secondary changes were also similar to those described previously, with deletion of the second TEL allele being the most common. Other secondary changes included duplication of the fusion gene, trisomy 21, and monosomy X.

California↗

Molecular characterization of archival adrenal tumor tissue from patients with ACTH-independent Cushing syndrome.

Cushing syndrome represents a multitude of signs and symptoms associated with long-term and excessive exposure to glucocorticoids. Solitary cortisol-producing adenomas (CPAs) account for most cases of ACTH-independent Cushing syndrome (CS). Technological advances in next-generation sequencing have significantly increased our understanding about the genetic landscape of CPAs. However, the conventional approach utilizes fresh/frozen tissue samples, which are not routinely available for most clinical adrenal adenoma specimens. This coupled with the fact that CS is relatively rare reduces the accessibility to CPAs for research. In order to circumvent this issue, our group recently developed a sequencing strategy that allowed the use of formalin-fixed paraffin-embedded (FFPE) CPA samples for mutation analysis. Our streamlined approach includes the visualization and genomic DNA (gDNA) capture of the cortisol-producing regions in the tumor using immunohistochemistry (IHC)-guided techniques followed by targeted and/or whole-exome sequencing analysis. This approach has the advantage of using both prospective and retrospective CPA cohorts since FFPE pathologic specimens are routinely banked. This review discusses this advanced approach using IHC-guided gDNA capture of pathologic tissue followed by NGS as a preferred method for mutational analysis of CPAs.

Humans↗

Optimization of coupled PCR amplification and cycle sequencing of cloned and genomic DNA.

We describe optimization of a coupled amplification and cycle sequencing (CAS) method for rapid characterization of cloned or genomic DNA. Our modification of this method, termed coupled PCR amplification and cycle sequencing (CPACS), utilizes commercially available reagents, does not require template purification and produces high-quality sequence ladders from nanogram quantities of complex genomic DNA. The reactions have been streamlined to permit automation. Finally, we show that the technique can be applied more efficiently in conjunction with the AutoTrans 350 Direct Transfer Electrophoresis System and 33P-labeled sequencing primers.

Autoanalysis↗

CEAS: cis-regulatory element annotation system.

The recent availability of high-density human genome tiling arrays enables biologists to conduct ChIP-chip experiments to locate the in vivo-binding sites of transcription factors in the human genome and explore the regulatory mechanisms. Once genomic regions enriched by transcription factor ChIP-chip are located, genome-scale downstream analyses are crucial but difficult for biologists without strong bioinformatics support. We designed and implemented the first web server to streamline the ChIP-chip downstream analyses. Given genome-scale ChIP regions, the cis-regulatory element annotation system (CEAS) retrieves repeat-masked genomic sequences, calculates GC content, plots evolutionary conservation, maps nearby genes and identifies enriched transcription factor-binding motifs. Biologists can utilize CEAS to retrieve useful information for ChIP-chip validation, assemble important knowledge to include in their publication and generate novel hypotheses (e.g. transcription factor cooperative partner) for further study. CEAS helps the adoption of ChIP-chip in mammalian systems and provides insights towards a more comprehensive understanding of transcriptional regulatory mechanisms. The URL of the server is http://ceas.cbi.pku.edu.cn.

Binding Sites↗

The evolving genome of Salmonella enterica serovar Pullorum.

Salmonella enterica serovar Pullorum is a fowl-adapted bacterial pathogen that causes dysentery (pullorum disease). Host adaptation and special pathogenesis make S. enterica serovar Pullorum an exceptionally good system for studies of bacterial evolution and speciation, especially regarding pathogen-host interactions and the acquisition of pathogenicity. We constructed a genome map of S. enterica serovar Pullorum RKS5078, using I-CeuI, XbaI, AvrII, and SpeI and Tn10 insertions. Pulsed-field gel electrophoresis was employed to separate the large DNA fragments generated by the endonucleases. The genome is 4,930 kb, which is similar to most salmonellas. However, the genome of S. enterica serovar Pullorum RKS5078 is organized very differently from the majority of salmonellas, with three major inversions and one translocation. This extraordinary genome structure was seen in most S. enterica serovar Pullorum strains examined, with different structures in a minority of S. enterica serovar Pullorum strains. We describe the coexistence of different genome structures among the same bacteria as genomic plasticity. Through comparisons with S. enterica serovar Typhimurium, we resolved seven putative insertions and eight deletions ranging in size from 12 to 157 kb. The genomic plasticity seen among S. enterica serovar Pullorum strains supported our hypothesis about its association with bacterial evolution: a large genomic insertion (157 kb in this case) disrupted the genomic balance, and rebalancing by independent recombination events in individual lineages resulted in diverse genome structures. As far as the structural plasticity exists, the S. enterica serovar Pullorum genome will continue evolving to reach a further streamlined and balanced structure.

Chromosome Mapping↗

The European Health Data Space and the Secondary Use of Sensitive Health Data.

INTRODUCTION: The European Health Data Space (EHDS) is one of the European Union's most ambitious data-governance projects. It aims to create a common framework through which electronic health data can be accessed and reused across Member States for care, research, innovation, policy, and public-interest purposes. Its practical viability depends not only on digital infrastructure, but also on legal, ethical, and organisational harmonisation, particularly for genetic and genomic data. METHODS: This paper examines the EHDS with emphasis on the secondary use of health data. It reviews the EHDS institutional architecture, discusses Finland's Findata as a national model for structured access, and analyses challenges for data holders and data donors, including interoperability, governance burdens, privacy protection, residual re-identification risk, and genomic-data sensitivity. RESULTS: A cross-border cancer-genomics case study shows that the EHDS can streamline data discovery and the routing of access requests, but does not by itself eliminate legal fragmentation, heterogeneous ethics review, and consent-related barriers. DISCUSSION: Effective implementation will require harmonisation beyond infrastructure, including clearer consent standards, more consistent ethics procedures, interoperable metadata, and proportionate safeguards for genomic data.

Electronic Health Records↗

On the synthesis and interpretation of consistent but weak gene-disease associations in the era of genome-wide association studies.

Emerging technologies are allowing researchers to study hundreds of thousands of genetic variants simultaneously as risk factors for common complex diseases. Both theoretical considerations and empirical evidence suggest that specific genetic variants causally associated with common diseases will have small effects (risk ratios mostly <2.0). However, the combination of even a few small effects (e.g. effects of fewer than 20 common genetic variants) could account for a sizeable population attributable fraction of common diseases and shed important light on disease pathogenesis and environmental determinants. Nevertheless, the inauguration of genome-wide association studies only magnifies the challenge of differentiating between the expected, true weak associations from the numerous spurious effects caused by misclassification, confounding and significance-chasing biases. Standards are urgently needed for presenting and interpreting cumulative evidence on gene-disease associations, especially for consistent but weak associations. Criteria for synthesis of the evidence should include sound methods for study conduct and analysis, biological plausibility, experimental evidence and adequate replication in large-scale, collaborative studies. Efforts by the Human Genome Epidemiology Network (HuGENet) are currently ongoing to streamline and operationalize these criteria for data on genetic associations with common diseases.

Cohort Studies↗

Double replacement: strategy for efficient introduction of subtle mutations into the murine Col1a-1 gene by homologous recombination in embryonic stem cells.

A subtle mutation that rendered type I collagen resistant to mammalian collagenase has been introduced into the murine Col1a-1 (recently redesignated Cola-1) gene by homologous recombination in embryonic stem (ES) cells. Initially, a "hit and run" procedure was used. Since two steps were required for introducing each mutation and more than one mutation was to be introduced in the same genomic region independently, we have developed a streamlined procedure that involves two sequential replacement-type homologous recombination events. In the first step, an internal deletion was introduced into the Col1a-1 locus along with the positive and negative selectable markers, neo and tk, to mark the region of interest. G418-resistant homologous recombinants were isolated and used in the second step in which the deleted Col1a-1 allele was replaced with a construct containing the desired mutation. Homologous recombinants containing the mutation were identified among the Tk- ES clones after selection with FIAU [1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil (called fialuridine)]. Approximately 10% of such clones contained the desired mutation. The double replacement procedure greatly reduces the time and amount of work required to introduce mutations independently into the same or closely linked regions. Once the homologous recombinants derived from the first step are established, the introduction of other mutations into the deleted region becomes a one-step procedure. For X number of introduced mutations, 2X selections are required with the "hit and run" approach, but only X + 1 are required with the double-replacement method. This innovative procedure could be very useful in studies of gene structure and function as well as gene expression and regulation.

Animals↗

Crystallization data mining in structural genomics: using positive and negative results to optimize protein crystallization screens.

Recent efforts to collect and mine crystallization data from structural genomics (SG) consortia have led to the identification of minimal screens and novel screening strategies that can be used to streamline the crystallization process. Two groups, the Joint Center for Structural Genomics and the University of Toronto, carried out large-scale crystallization trials on different sets of bacterial targets (539, JCSG and 755, Toronto), using different sample processing and crystallization methods, and then analyzed their results to identify the smallest subset of conditions that would have crystallized the maximum number of protein targets. The JCSG Core Screen contains 67 conditions (from 480) while the Toronto Minimal Screen contains 6 (from 48). While the exact conditions included in the two screens do not overlap, the major precipitants of the conditions are similar and thus both screens can be used to determine if a protein has a natural propensity to crystallize. In addition, studies from other groups including the University of Queensland, the Mycobacterium tuberculosis SG group, the Southeast Collaboratory for SG, and the York Structural Biology Laboratory indicate that alternative crystallization strategies may be more successful at identifying initial crystallization conditions than typical sparse matrix screens. These minimal screens and alternative screening strategies are already being used to optimize the crystallization processes within large SG efforts. The differences between these results, however, demonstrate that additional studies which examine the influence of protein biophysical properties and sample preparation methods on crystal formation must also be carried out before more robust screens can be identified.

Chemistry Techniques, Analytical↗

One large-insert plant-transformation-competent BIBAC library and three BAC libraries of Japonica rice for genome research in rice and other grasses.

We report one large-insert BIBAC library and three BAC libraries for japonica rice cv Nipponbare. The BIBAC library was constructed in the HindIII site of a plant-transformation-competent binary vector (pCLD04541) and the three BAC libraries were constructed in the BamHI, HindIII and EcoRI sites of a BAC vector (pECBAC1), respectively. Each library contains 23,040 clones, has an average insert size of 130 kb, 170 kb, 150 kb and 156 kb, and covers 6.7x, 8.7x, 7.7x and 8.0 x rice haploid genomes, respectively. The combined libraries contain 92,160 clones in total, covering 31.1 x rice haploid genomes. To demonstrate their utility, we screened the libraries with 55 DNA markers mapped to chromosome 8 of the rice genetic maps and analyzed a number of clones by the restriction fingerprinting and contig assembly method. The results indicate that the libraries completely cover the rice genome and, thus, are well-suited for genome research in rice and other gramineous crops. The BIBAC library represents the first plant-transformation-competent large-insert DNA library for rice, which will streamline map-based cloning, functional analysis of the rice genome sequence and molecular breeding in rice and other grass species. These libraries are being used in the development of a whole-genome, BAC/BIBAC-based, integrated physical, genetic and sequence map of rice and in the research of genome-wide comparative genomics of grass species.

Journal Article↗

CRISPRessoSea: streamlined analysis and comparison of pooled amplicon CRISPR screens.

BACKGROUND: CRISPR genome editing enables precise modification of genomic targets but may also induce unintended edits at off-target sites with similar sequences. Pooled amplicon sequencing can assess on- and off-target editing across many samples, yet analyzing, aggregating, and visualizing results from multiple pooled experiments remains challenging. Tools to simplify and standardize these analyses are needed to provide reproducible and comparable interpretation of editing data. RESULTS: We developed CRISPRessoSea, a software package that processes, compares, and visualizes genome editing rates from pooled amplicon sequencing experiments. The tool provides standardized workflows for analyzing editing across multiple targets and samples, supports both nuclease- and base-editing modalities, and generates clear, data-rich summaries suitable for downstream interpretation. CONCLUSIONS: CRISPRessoSea facilitates reproducible, scalable analysis of CRISPR editing outcomes across diverse experimental designs, enabling more efficient and transparent assessment of genome editing specificity. The software is freely available at https://github.com/clementlab/CRISPRessoSea .

Software↗

VirDetector: a bioinformatic pipeline for virus surveillance using nanopore sequencing.

SUMMARY: Virus surveillance programmes are designed to counter the growing threat of viral outbreaks to human health. Nanopore sequencing, in particular, has proven to be suitable for this purpose, as it is readily available and provides rapid results. However, as special bioinformatic programs are required to extract the relevant information from the sequencing data, applications are needed that allow users without extensive bioinformatics knowledge to carry out the relevant analysis steps. We present VirDetector, a bioinformatic pipeline for virus surveillance using nanopore sequencing. The pipeline automatically installs all required programs and databases and allows all its steps to be executed with a single console command. After preprocessing the samples, including the possibility for basecalling, the pipeline classifies each sample taxonomically and reconstructs the viral consensus genomes, which are then used in phylogenetic analyses. This streamlined workflow provides a user-friendly and efficient solution for monitoring viral pathogens. AVAILABILITY AND IMPLEMENTATION: VirDetector is freely available at https://github.com/NLKaiser/VirDetector and https://zenodo.org/records/14637302 (10.5281/zenodo.14637302).

Nanopore Sequencing↗

Refined repetitive sequence searches utilizing a fast hash function and cross species information retrievals.

BACKGROUND: Searching for small tandem/disperse repetitive DNA sequences streamlines many biomedical research processes. For instance, whole genomic array analysis in yeast has revealed 22 PHO-regulated genes. The promoter regions of all but one of them contain at least one of the two core Pho4p binding sites, CACGTG and CACGTT. In humans, microsatellites play a role in a number of rare neurodegenerative diseases such as spinocerebellar ataxia type 1 (SCA1). SCA1 is a hereditary neurodegenerative disease caused by an expanded CAG repeat in the coding sequence of the gene. In bacterial pathogens, microsatellites are proposed to regulate expression of some virulence factors. For example, bacteria commonly generate intra-strain diversity through phase variation which is strongly associated with virulence determinants. A recent analysis of the complete sequences of the Helicobacter pylori strains 26695 and J99 has identified 46 putative phase-variable genes among the two genomes through their association with homopolymeric tracts and dinucleotide repeats. Life scientists are increasingly interested in studying the function of small sequences of DNA. However, current search algorithms often generate thousands of matches -- most of which are irrelevant to the researcher. RESULTS: We present our hash function as well as our search algorithm to locate small sequences of DNA within multiple genomes. Our system applies information retrieval algorithms to discover knowledge of cross-species conservation of repeat sequences. We discuss our incorporation of the Gene Ontology (GO) database into these algorithms. We conduct an exhaustive time analysis of our system for various repetitive sequence lengths. For instance, a search for eight bases of sequence within 3.224 GBases on 49 different chromosomes takes 1.147 seconds on average. To illustrate the relevance of the search results, we conduct a search with and without added annotation terms for the yeast Pho4p binding sites, CACGTG and CACGTT. Also, a cross-species search is presented to illustrate how potential hidden correlations in genomic data can be quickly discerned. The findings in one species are used as a catalyst to discover something new in another species. These experiments also demonstrate that our system performs well while searching multiple genomes -- without the main memory constraints present in other systems. CONCLUSION: We present a time-efficient algorithm to locate small segments of DNA and concurrently to search the annotation data accompanying the sequence. Genome-wide searches for short sequences often return hundreds of hits. Our experiments show that subsequently searching the annotation data can refine and focus the results for the user. Our algorithms are also space-efficient in terms of main memory requirements. Source code is available upon request.

Algorithms↗

Impact of precision oncology research in pediatric poor prognosis cancer: patient, parent and healthcare provider perspectives.

BACKGROUND: Comprehensive genomic analyses are increasingly accessible to children, adolescents and young adults (AYAs) with poor prognosis cancers. Challenges and successes of pediatric precision oncology studies from the perspectives of AYA patients, parents and healthcare providers (HCPs) are poorly described. METHODS: Between March 2021 and May 2023, we interviewed AYA patients (12-21&#xa0;years), parents and HCPs who participated in pediatric precision oncology studies for poor prognosis cancers in British Columbia. Interviews followed an investigator-developed semi-structured topic guide. Data were coded inductively and deductively by one qualitative researcher and one trainee, supported by two additional team members. Analytic themes were established using qualitative thematic analysis. RESULTS: We interviewed 9 AYAs, 10 parents, and 17 HCPs. We identified five analytic themes: importance of clear communication of study information between patients, families and multidisciplinary HCPs; a need to support disclosure, understanding and clinical integration of research results; barriers to accessing innovative therapy and mitigation strategies; approaches to managing parent, patient and HCP hopes and expectations; personal challenges and stressors related to participation. CONCLUSIONS: We highlight unmet needs and offer practical considerations for integrating precision oncology into clinical practice. Considerations include educating and supporting oncologists through genomics results disclosure, increasing engagement with multidisciplinary HCPs, streamlining access to study information and results, coordinating efforts to clinically validate results and access therapies, and establishing real-world outcome data to inform clinical decision-making. Implementation of these strategies will optimize care for patients and families who are navigating poor prognosis cancers.

Humans↗

A BAC- and BIBAC-based physical map of the soybean genome.

Genome-wide physical maps are crucial to many aspects of advanced genome research. We report a genome-wide, bacterial artificial chromosome (BAC) and plant-transformation-competent binary large-insert plasmid clone (hereafter BIBAC)-based physical map of the soybean genome. The map was constructed from 78001 clones from five soybean BAC and BIBAC libraries representing 9.6 haploid genomes and three cultivars, and consisted of 2905 BAC/BIBAC contigs, estimated to span 1408 Mb in physical length. We evaluated the reliability of the map contigs using different contig assembly strategies, independent contig building methods, DNA marker hybridization, and different fingerprinting methods, and the results showed that the contigs were assembled properly. Furthermore, we tested the feasibility of integrating the physical map with the existing soybean composite genetic map using 388 DNA markers. The results further confirmed the nature of the ancient tetraploid origin of soybean and indicated that it is feasible to integrate the physical map with the linkage map even though greater efforts are needed. This map represents the first genome-wide, BAC/BIBAC-based physical map of the soybean genome and would provide a platform for advanced genome research of soybean and other legume species. The inclusion of BIBACs in the map would streamline the utility of the map for positional cloning of genes and QTLs, and functional analysis of soybean genomic sequences.

Chromosomes, Artificial, Bacterial↗

Exploiting the potential of knowledge management in R&D and drug discovery: extracting value from information.

While the life sciences industry is still coming to terms with the consequences of the Human Genome Project, the market place is forcing businesses to streamline, re-focus and even merge with or acquire businesses across the entire sector. In these troubled times, is there a place for knowledge management in research and development and drug discovery? This article reviews some of the major challenges in realizing the value of information and asks if knowledge management has made a significant impact in drug discovery.

Databases as Topic↗

Measuring Cell Dimensions in Fission Yeast Using Machine Learning.

In fission yeast (Schizosaccharomyces pombe), cell length is a crucial indicator of cell cycle progression. Microscopy screens that examine the effect of agents or genotypes suspected of altering genomic or metabolic stability and thus cell size are crucial for studying disruptions to cell cycle dynamics. This method is based on using an automated cell segmentation algorithm to measure S. pombe cells imaged by brightfield (BF) microscopy methods. PhotoPhenosizer (PP) is a machine learning-based tool designed for automated cell measuring and dimensional analysis of morphology frequency distributions. Integration of this method into large-scale pipelines for tracking cell dimension change streamlines morphological measurements, which facilitates the examination of cellular responses to genomic and metabolic stresses. In this protocol, we use PP to observe the effect of genomic instability on cell size dynamics over a 12-day chronological lifespan assay. Our results show that relative to wild-type cells, a replication stress mutant shows larger cells during chronological aging in excess glucose media. Our results are consistent with activation of checkpoints that regulate cell morphology in response to DNA damage. This method's application highlights the relevance of its incorporation in experimental routines that require large-scale image processing and its adoption by users with routine needs in S. pombe molecular research projects.

Schizosaccharomyces↗