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Cell Systems Mar 2017A systems-level understanding of Gram-positive bacteria is important from both an environmental and health perspective and is most easily obtained when high-quality,...
A systems-level understanding of Gram-positive bacteria is important from both an environmental and health perspective and is most easily obtained when high-quality, validated genomic resources are available. To this end, we constructed two ordered, barcoded, erythromycin-resistance- and kanamycin-resistance-marked single-gene deletion libraries of the Gram-positive model organism, Bacillus subtilis. The libraries comprise 3,968 and 3,970 genes, respectively, and overlap in all but four genes. Using these libraries, we update the set of essential genes known for this organism, provide a comprehensive compendium of B. subtilis auxotrophic genes, and identify genes required for utilizing specific carbon and nitrogen sources, as well as those required for growth at low temperature. We report the identification of enzymes catalyzing several missing steps in amino acid biosynthesis. Finally, we describe a suite of high-throughput phenotyping methodologies and apply them to provide a genome-wide analysis of competence and sporulation. Altogether, we provide versatile resources for studying gene function and pathway and network architecture in Gram-positive bacteria.
Topics: Amino Acids; Bacillus subtilis; Gene Deletion; Gene Library; Genomic Library; Genomics; High-Throughput Screening Assays; Sequence Deletion; Spores, Bacterial
PubMed: 28189581
DOI: 10.1016/j.cels.2016.12.013 -
Nature Methods Aug 2023Capture array-based spatial transcriptomics methods have been widely used to resolve gene expression in tissues; however, their spatial resolution is limited by the...
Capture array-based spatial transcriptomics methods have been widely used to resolve gene expression in tissues; however, their spatial resolution is limited by the density of the array. Here we present expansion spatial transcriptomics to overcome this limitation by clearing and expanding tissue prior to capturing the entire polyadenylated transcriptome with an enhanced protocol. This approach enables us to achieve higher spatial resolution while retaining high library quality, which we demonstrate using mouse brain samples.
Topics: Animals; Mice; Gene Expression Profiling; Gene Library; Poly A; Transcriptome
PubMed: 37349575
DOI: 10.1038/s41592-023-01911-1 -
Nucleic Acids Research Aug 2004We have developed a new primer design method based on the QuickChange site-directed mutagenesis protocol, which significantly improves the PCR amplification efficiency....
We have developed a new primer design method based on the QuickChange site-directed mutagenesis protocol, which significantly improves the PCR amplification efficiency. This design method minimizes primer dimerization and ensures the priority of primer-template annealing over primer self-pairing during the PCR. Several different multiple mutations (up to 7 bases) were successfully performed with this partial overlapping primer design in a variety of vectors ranging from 4 to 12 kb in length. In comparison, all attempts failed when using complete-overlapping primer pairs as recommended in the standard QuickChange protocol. Our protocol was further extended to site-saturation mutagenesis by introducing randomized codons. Our data indicated no specific sequence selection during library construction, with the randomized positions resulting in average occurrence of each base in each position. This method should be useful to facilitate the preparation of high-quality site saturation libraries.
Topics: DNA Primers; Directed Molecular Evolution; Electrophoresis, Agar Gel; Gene Library; Mutagenesis, Site-Directed; Polymerase Chain Reaction; Protein Engineering
PubMed: 15304544
DOI: 10.1093/nar/gnh110 -
Cell Chemical Biology Aug 2021The generation of a library of variant genes is a prerequisite of directed evolution, a powerful tool for biomolecular engineering. As the number of all possible... (Review)
Review
The generation of a library of variant genes is a prerequisite of directed evolution, a powerful tool for biomolecular engineering. As the number of all possible sequences often far exceeds the diversity of a practical library, methods that allow efficient library diversification in living cells are essential for in vivo directed evolution technologies to effectively sample the sequence space and allow hits to emerge. While traditional whole-genome mutagenesis often results in toxicity and the emergence of "cheater" mutations, recent developments that exploit the targeting and editing abilities of genome editors to facilitate in vivo library diversification have allowed for precise mutagenesis focused on specific genes of interest, higher mutational density, and reduced the occurrence of cheater mutations. This minireview summarizes recent advances in genome editor-directed in vivo library diversification and provides an outlook on their future applications in chemical biology.
Topics: Directed Molecular Evolution; Gene Editing; Gene Library
PubMed: 34107297
DOI: 10.1016/j.chembiol.2021.05.008 -
Molecular & Cellular Proteomics : MCP Sep 2023Data-independent acquisition (DIA) mass spectrometry-based proteomics generates reproducible proteome data. The complex processing of the DIA data has led to the...
Data-independent acquisition (DIA) mass spectrometry-based proteomics generates reproducible proteome data. The complex processing of the DIA data has led to the development of multiple data analysis tools. In this study, we assessed the performance of five tools (OpenSWATH, EncyclopeDIA, Skyline, DIA-NN, and Spectronaut) using six DIA datasets obtained from TripleTOF, Orbitrap, and TimsTOF Pro instruments. By comparing identification and quantification metrics and examining shared and unique cross-tool identifications, we evaluated both library-based and library-free approaches. Our findings indicate that library-free approaches outperformed library-based methods when the spectral library had limited comprehensiveness. However, our results also suggest that constructing a comprehensive library still offers benefits for most DIA analyses. This study provides comprehensive guidance for DIA data analysis tools, benefiting both experienced and novice users of DIA-mass spectrometry technology.
Topics: Mass Spectrometry; Proteomics; Proteome; Gene Library; Data Analysis
PubMed: 37481071
DOI: 10.1016/j.mcpro.2023.100623 -
SLAS Discovery : Advancing Life... Jul 2020Secreted proteins and their cognate plasma membrane receptors regulate human physiology by transducing signals from the extracellular environment into cells resulting in... (Review)
Review
Secreted proteins and their cognate plasma membrane receptors regulate human physiology by transducing signals from the extracellular environment into cells resulting in different cellular phenotypes. Systematic use of secretome proteins in assays enables discovery of novel biology and signaling pathways. Several secretome-based phenotypic screening platforms have been described in the literature and shown to facilitate target identification in drug discovery. In this review, we summarize the current status of secretome-based screening. This includes annotation, production, quality control, and sample management of secretome libraries, as well as how secretome libraries have been applied to discover novel target biology using different disease-relevant cell-based assays. A workflow for secretome-based screening is shared based on the AstraZeneca experience. The secretome library offers several advantages compared with other libraries used for target discovery: (1) screening using a secretome library directly identifies the active protein and, in many cases, its cognate receptor, enabling a rapid understanding of the disease pathway and subsequent formation of target hypotheses for drug discovery; (2) the secretome library covers significant areas of biological signaling space, although the size of this library is small; (3) secretome proteins can be added directly to cells without additional manipulation. These factors make the secretome library ideal for testing in physiologically relevant cell types, and therefore it represents an attractive approach to phenotypic target discovery.
Topics: Cellular Microenvironment; Drug Discovery; Gene Library; High-Throughput Screening Assays; Humans; Proteome
PubMed: 32425085
DOI: 10.1177/2472555220917113 -
BioTechniques Jul 2023
Topics: Epigenome; Gene Library; Chromatin; Chromatin Immunoprecipitation; High-Throughput Nucleotide Sequencing
PubMed: 37386860
DOI: 10.2144/btn-2022-0118 -
Bioinformatics (Oxford, England) May 2023'PascalX' is a Python library providing fast and accurate tools for mapping SNP-wise GWAS summary statistics. Specifically, it allows for scoring genes and annotated...
SUMMARY
'PascalX' is a Python library providing fast and accurate tools for mapping SNP-wise GWAS summary statistics. Specifically, it allows for scoring genes and annotated gene sets for enrichment signals based on data from, both, single GWAS and pairs of GWAS. The gene scores take into account the correlation pattern between SNPs. They are based on the cumulative density function of a linear combination of χ2 distributed random variables, which can be calculated either approximately or exactly to high precision. Acceleration via multithreading and GPU is supported. The code of PascalX is fully open source and well suited as a base for method development in the GWAS enrichment test context.
AVAILABILITY AND IMPLEMENTATION
The source code is available at https://github.com/BergmannLab/PascalX and archived under doi://10.5281/zenodo.4429922. A user manual with usage examples is available at https://bergmannlab.github.io/PascalX/.
Topics: Genome-Wide Association Study; Gene Library; Software; Polymorphism, Single Nucleotide; Libraries
PubMed: 37137228
DOI: 10.1093/bioinformatics/btad296 -
Biotechnology Advances 2020Next generation sequencing is in the process of evolving from a technology used for research purposes to one which is applied in clinical diagnostics. Recently... (Review)
Review
Next generation sequencing is in the process of evolving from a technology used for research purposes to one which is applied in clinical diagnostics. Recently introduced high throughput and benchtop instruments offer fully automated sequencing runs at a lower cost per base and faster assay times. In turn, the complex and cumbersome library preparation, starting with isolated nucleic acids and resulting in amplified and barcoded DNA with sequencing adapters, has been identified as a significant bottleneck. Library preparation protocols usually consist of a multistep process and require costly reagents and substantial hands-on-time. Considerable emphasis will need to be placed on standardisation to ensure robustness and reproducibility. This review presents an overview of the current state of automation of library preparation for next generation sequencing. Major challenges associated with library preparation are outlined and different automation strategies are classified according to their functional principle. Pipetting workstations allow high-throughput processing yet offer limited flexibility, whereas microfluidic solutions offer great potential due to miniaturisation and decreased investment costs. For the emerging field of single cell transcriptomics for example, microfluidics enable singularisation of tens of thousands of cells in nanolitre droplets and barcoding of the RNA to assign each nucleic acid sequence to its cell of origin. Finally, two applications, the characterisation of bacterial pathogens and the sequencing within human immunogenetics, are outlined and benefits of automation are discussed.
Topics: Automation; Gene Library; High-Throughput Nucleotide Sequencing; Humans; RNA; Reproducibility of Results
PubMed: 32199980
DOI: 10.1016/j.biotechadv.2020.107537 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Jan 2021Directed evolution is a cyclic process that alternates between constructing different genes and screening functional gene variants. It has been widely used in... (Review)
Review
Directed evolution is a cyclic process that alternates between constructing different genes and screening functional gene variants. It has been widely used in optimization and analysis of DNA sequence, gene function and protein structure. It includes random gene libraries construction, gene expression in suitable hosts and mutant libraries screening. The key to construct gene library is the storage capacity and mutation diversity, to screen is high sensitivity and high throughput. This review discusses the latest advances in directed evolution. These new technologies greatly accelerate and simplify the traditional directional evolution process and promote the development of directed evolution.
Topics: Base Sequence; Directed Molecular Evolution; Gene Library; Mutation; Proteins
PubMed: 33501798
DOI: 10.13345/j.cjb.200261