scholarly journals Characterisation of a Novel Benzopyran Library Using High-Throughput Microscopy

2021 ◽  
Author(s):  
◽  
Jeffrey Sheridan

<p>Drug discovery is a multi-disciplinary field incorporating both chemistry and biology to create novel pharmaceuticals. Nature synthesizes a diverse range of chemical entities that can demonstrate a wide range of biological interactions, though often produces these compounds in small amounts. Using natures structural diversity as a template, organic synthetic chemistry can tap into the structures of natural products and provide novel structures as well as overcome supply issues through large-scale synthetic chemical processes. A novel benzopyran library was synthesised by Sandile Simelane by reacting 3,4,6,-tri-O-acetyl-D-galactal with various phenols to create a novel focused library of bridged benzopyrans. Each molecule has unique functional groups at defined points in the structure due to varying the functional groups on the phenol, allowing for variation within the library whilst retaining the core scaffold. In this thesis, the bioactivity of this novel benzopyran library was explored using a phenotypic screen measuring growth inhibition. A compound, S13, was determined to be the most potent in the library, therefore genome-wide screening was performed using S13. High-throughput microscopy of 4,100 strains, each with a different GFP-tagged protein, was utilized to determine proteins that increased in abundance or changed localization in response to perturbation with S13. Following treatment with S13, the yeast vacuole increased in size due to an aggregation of proteins in the vacuolar lumen. The increase in vacuole size was coincident with a decrease in vacuolar acidity, potentially disrupted autophagy and the upregulation of several proteins involved in ergosterol biosynthesis. Together, these results reveal a novel bridged benzopyran that increases vacuolar size and pH through an epistatic mechanism involving ergosterol biosynthesis.</p>

2021 ◽  
Author(s):  
◽  
Jeffrey Sheridan

<p>Drug discovery is a multi-disciplinary field incorporating both chemistry and biology to create novel pharmaceuticals. Nature synthesizes a diverse range of chemical entities that can demonstrate a wide range of biological interactions, though often produces these compounds in small amounts. Using natures structural diversity as a template, organic synthetic chemistry can tap into the structures of natural products and provide novel structures as well as overcome supply issues through large-scale synthetic chemical processes. A novel benzopyran library was synthesised by Sandile Simelane by reacting 3,4,6,-tri-O-acetyl-D-galactal with various phenols to create a novel focused library of bridged benzopyrans. Each molecule has unique functional groups at defined points in the structure due to varying the functional groups on the phenol, allowing for variation within the library whilst retaining the core scaffold. In this thesis, the bioactivity of this novel benzopyran library was explored using a phenotypic screen measuring growth inhibition. A compound, S13, was determined to be the most potent in the library, therefore genome-wide screening was performed using S13. High-throughput microscopy of 4,100 strains, each with a different GFP-tagged protein, was utilized to determine proteins that increased in abundance or changed localization in response to perturbation with S13. Following treatment with S13, the yeast vacuole increased in size due to an aggregation of proteins in the vacuolar lumen. The increase in vacuole size was coincident with a decrease in vacuolar acidity, potentially disrupted autophagy and the upregulation of several proteins involved in ergosterol biosynthesis. Together, these results reveal a novel bridged benzopyran that increases vacuolar size and pH through an epistatic mechanism involving ergosterol biosynthesis.</p>


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Michal Kucharski ◽  
Jaishree Tripathi ◽  
Sourav Nayak ◽  
Lei Zhu ◽  
Grennady Wirjanata ◽  
...  

Abstract Background Sequencing technology advancements opened new opportunities to use transcriptomics for studying malaria pathology and epidemiology. Even though in recent years the study of whole parasite transcriptome proved to be essential in understanding parasite biology there is no compiled up-to-date reference protocol for the efficient generation of transcriptome data from growing number of samples. Here, a comprehensive methodology on how to preserve, extract, amplify, and sequence full-length mRNA transcripts from Plasmodium-infected blood samples is presented that can be fully streamlined for high-throughput studies. Results The utility of various commercially available RNA-preserving reagents in a range of storage conditions was evaluated. Similarly, several RNA extraction protocols were compared and the one most suitable method for the extraction of high-quality total RNA from low-parasitaemia and low-volume blood samples was established. Furthermore, the criteria needed to evaluate the quality and integrity of Plasmodium RNA in the presence of human RNA was updated. Optimization of SMART-seq2 amplification method to better suit AT-rich Plasmodium falciparum RNA samples allowed us to generate high-quality transcriptomes from as little as 10 ng of total RNA and a lower parasitaemia limit of 0.05%. Finally, a modified method for depletion of unwanted human haemoglobin transcripts using in vitro CRISPR-Cas9 treatment was designed, thus improving parasite transcriptome coverage in low parasitaemia samples. To prove the functionality of the pipeline for both laboratory and field strains, the highest  2-hour resolution RNA-seq transcriptome for P. falciparum 3D7 intraerythrocytic life cycle available to  date was generated, and the entire protocol was applied to create the largest transcriptome data from Southeast Asian field isolates. Conclusions Overall, the presented methodology is an inclusive pipeline for generation of good quality transcriptomic data from a diverse range of Plasmodium-infected blood samples with varying parasitaemia and RNA inputs. The flexibility of this pipeline to be adapted to robotic handling will facilitate both small and large-scale future transcriptomic studies in the field of malaria.


2010 ◽  
Vol 5 ◽  
pp. BMI.S5062 ◽  
Author(s):  
Stephanie J. Loomis ◽  
Lana M. Olson ◽  
Louis R. Pasquale ◽  
Janey Wiggs ◽  
Daniel Mirel ◽  
...  

It is unclear if buccal cell samples contain sufficient human DNA with adequately sized fragments for high throughput genetic bioassays. Yet buccal cell sample collection is an attractive alternative to gathering blood samples for genetic epidemiologists engaged in large-scale genetic biomarker studies. We assessed the genotyping efficiency (GE) and genotyping concordance (GC) of buccal cell DNA samples compared to corresponding blood DNA samples, from 32 Nurses' Health Study (NHS) participants using the Illumina Infinium 660W-Quad platform. We also assessed how GE and GC accuracy varied as a function of DNA concentration using serial dilutions of buccal DNA samples. Finally we determined the nature and genomic distribution of discordant genotypes in buccal DNA samples. The mean GE of undiluted buccal cell DNA samples was high (99.32%), as was the GC between the paired buccal and blood samples (99.29%). GC between the dilutions versus the undiluted buccal DNA was also very high (>97%), though both GE and GC notably declined at DNA concentrations less than 5 ng/μl. Most (>95%) genotype determinations in buccal cell samples were of the “missing call” variety (as opposed to the “alternative genotype call” variety) across the spectrum of buccal DNA concentrations studied. Finally, for buccal DNA concentration above 1.7 ng/ul, discordant genotyping calls did not cluster in any particular chromosome. Buccal cell-derived DNA represents a viable alternative to blood DNA for genotyping on a high-density platform.


Author(s):  
Donovan H Parks ◽  
Michael Imelfort ◽  
Connor T Skennerton ◽  
Philip Hugenholtz ◽  
Gene W Tyson

Large-scale recovery of genomes from isolates, single cells, and metagenomic data has been made possible by advances in computational methods and substantial reductions in sequencing costs. While this increasing breadth of draft genomes is providing key information regarding the evolutionary and functional diversity of microbial life, it has become impractical to finish all available reference genomes. Making robust biological inferences from draft genomes requires accurate estimates of their completeness and contamination. Current methods for assessing genome quality are ad hoc and generally make use of a limited number of ‘marker’ genes conserved across all bacterial or archaeal genomes. Here we introduce CheckM, an automated method for assessing the quality of a genome using a broader set of marker genes specific to the position of a genome within a reference genome tree and information about the collocation of these genes. We demonstrate the effectiveness of CheckM using synthetic data and a wide range of isolate, single cell and metagenome derived genomes. CheckM is shown to provide accurate estimates of genome completeness and contamination, and to outperform existing approaches. Using CheckM, we identify a diverse range of errors currently impacting publicly available isolate genomes and demonstrate that genomes obtained from single cells and metagenomic data vary substantially in quality. In order to facilitate the use of draft genomes, we propose an objective measure of genome quality that can be used to select genomes suitable for specific gene- and genome-centric analyses of microbial communities.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nicole Gruenheit ◽  
Amy Baldwin ◽  
Balint Stewart ◽  
Sarah Jaques ◽  
Thomas Keller ◽  
...  

Abstract Background Genomes can be sequenced with relative ease, but ascribing gene function remains a major challenge. Genetically tractable model systems are crucial to meet this challenge. One powerful model is the social amoeba Dictyostelium discoideum, a eukaryotic microbe widely used to study diverse questions in the cell, developmental and evolutionary biology. Results We describe REMI-seq, an adaptation of Tn-seq, which allows high throughput, en masse, and quantitative identification of the genomic site of insertion of a drug resistance marker after restriction enzyme-mediated integration. We use REMI-seq to develop tools which greatly enhance the efficiency with which the sequence, transcriptome or proteome variation can be linked to phenotype in D. discoideum. These comprise (1) a near genome-wide resource of individual mutants and (2) a defined pool of ‘barcoded’ mutants to allow large-scale parallel phenotypic analyses. These resources are freely available and easily accessible through the REMI-seq website that also provides comprehensive guidance and pipelines for data analysis. We demonstrate that integrating these resources allows novel regulators of cell migration, phagocytosis and macropinocytosis to be rapidly identified. Conclusions We present methods and resources, generated using REMI-seq, for high throughput gene function analysis in a key model system.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Kaushik Raj ◽  
Naveen Venayak ◽  
Patrick Diep ◽  
Sai Akhil Golla ◽  
Alexander F. Yakunin ◽  
...  

Abstract Background Microorganisms can be metabolically engineered to produce a wide range of commercially important chemicals. Advancements in computational strategies for strain design and synthetic biological techniques to construct the designed strains have facilitated the generation of large libraries of potential candidates for chemical production. Consequently, there is a need for high-throughput laboratory scale techniques to characterize and screen these candidates to select strains for further investigation in large scale fermentation processes. Several small-scale fermentation techniques, in conjunction with laboratory automation have enhanced the throughput of enzyme and strain phenotyping experiments. However, such high throughput experimentation typically entails large operational costs and generate massive amounts of laboratory plastic waste. Results In this work, we develop an eco-friendly automation workflow that effectively calibrates and decontaminates fixed-tip liquid handling systems to reduce tip waste. We also investigate inexpensive methods to establish anaerobic conditions in microplates for high-throughput anaerobic phenotyping. To validate our phenotyping platform, we perform two case studies—an anaerobic enzyme screen, and a microbial phenotypic screen. We used our automation platform to investigate conditions under which several strains of E. coli exhibit the same phenotypes in 0.5 L bioreactors and in our scaled-down fermentation platform. We also propose the use of dimensionality reduction through t-distributed stochastic neighbours embedding (t-SNE) in conjunction with our phenotyping platform to effectively cluster similarly performing strains at the bioreactor scale. Conclusions Fixed-tip liquid handling systems can significantly reduce the amount of plastic waste generated in biological laboratories and our decontamination and calibration protocols could facilitate the widespread adoption of such systems. Further, the use of t-SNE in conjunction with our automation platform could serve as an effective scale-down model for bioreactor fermentations. Finally, by integrating an in-house data-analysis pipeline, we were able to accelerate the ‘test’ phase of the design-build-test-learn cycle of metabolic engineering.


2021 ◽  
Author(s):  
Brian C Zhang ◽  
Arjun Biddanda ◽  
Pier Francesco Palamara

Accurate inference of gene genealogies from genetic data has the potential to facilitate a wide range of analyses. We introduce a method for accurately inferring biobank-scale genome-wide genealogies from sequencing or genotyping array data, as well as strategies to utilize genealogies within linear mixed models to perform association and other complex trait analyses. We use these new methods to build genome-wide genealogies using genotyping data for 337,464 UK Biobank individuals and to detect associations in 7 complex traits. Genealogy-based association detects more rare and ultra-rare signals (N = 133, frequency range 0.0004% - 0.1%) than genotype imputation from ~65,000 sequenced haplotypes (N = 65). In a subset of 138,039 exome sequencing samples, these associations strongly tag (average r = 0.72) underlying sequencing variants, which are enriched for missense (2.3×) and loss-of-function (4.5×) variation. Inferred genealogies also capture additional association signals in higher frequency variants. These results demonstrate that large-scale inference of gene genealogies may be leveraged in the analysis of complex traits, complementing approaches that require the availability of large, population-specific sequencing panels.


2020 ◽  
Vol 49 (D1) ◽  
pp. D825-D830 ◽  
Author(s):  
◽  
Guang-Hui Liu ◽  
Yiming Bao ◽  
Jing Qu ◽  
Weiqi Zhang ◽  
...  

Abstract Organismal aging is driven by interconnected molecular changes encompassing internal and extracellular factors. Combinational analysis of high-throughput ‘multi-omics’ datasets (gathering information from genomics, epigenomics, transcriptomics, proteomics, metabolomics and pharmacogenomics), at either populational or single-cell levels, can provide a multi-dimensional, integrated profile of the heterogeneous aging process with unprecedented throughput and detail. These new strategies allow for the exploration of the molecular profile and regulatory status of gene expression during aging, and in turn, facilitate the development of new aging interventions. With a continually growing volume of valuable aging-related data, it is necessary to establish an open and integrated database to support a wide spectrum of aging research. The Aging Atlas database aims to provide a wide range of life science researchers with valuable resources that allow access to a large-scale of gene expression and regulation datasets created by various high-throughput omics technologies. The current implementation includes five modules: transcriptomics (RNA-seq), single-cell transcriptomics (scRNA-seq), epigenomics (ChIP-seq), proteomics (protein–protein interaction), and pharmacogenomics (geroprotective compounds). Aging Atlas provides user-friendly functionalities to explore age-related changes in gene expression, as well as raw data download services. Aging Atlas is freely available at https://bigd.big.ac.cn/aging/index.


Author(s):  
Tianshun Gao ◽  
Jiang Qian

Abstract Enhancers are distal cis-regulatory elements that activate the transcription of their target genes. They regulate a wide range of important biological functions and processes, including embryogenesis, development, and homeostasis. As more and more large-scale technologies were developed for enhancer identification, a comprehensive database is highly desirable for enhancer annotation based on various genome-wide profiling datasets across different species. Here, we present an updated database EnhancerAtlas 2.0 (http://www.enhanceratlas.org/indexv2.php), covering 586 tissue/cell types that include a large number of normal tissues, cancer cell lines, and cells at different development stages across nine species. Overall, the database contains 13 494 603 enhancers, which were obtained from 16 055 datasets using 12 high-throughput experiment methods (e.g. H3K4me1/H3K27ac, DNase-seq/ATAC-seq, P300, POLR2A, CAGE, ChIA-PET, GRO-seq, STARR-seq and MPRA). The updated version is a huge expansion of the first version, which only contains the enhancers in human cells. In addition, we predicted enhancer–target gene relationships in human, mouse and fly. Finally, the users can search enhancers and enhancer–target gene relationships through five user-friendly, interactive modules. We believe the new annotation of enhancers in EnhancerAtlas 2.0 will facilitate users to perform useful functional analysis of enhancers in various genomes.


2021 ◽  
Vol 11 ◽  
Author(s):  
Mariangela Arca ◽  
Tristan Mary-Huard ◽  
Brigitte Gouesnard ◽  
Aurélie Bérard ◽  
Cyril Bauland ◽  
...  

Genebanks harbor original landraces carrying many original favorable alleles for mitigating biotic and abiotic stresses. Their genetic diversity remains, however, poorly characterized due to their large within genetic diversity. We developed a high-throughput, cheap and labor saving DNA bulk approach based on single-nucleotide polymorphism (SNP) Illumina Infinium HD array to genotype landraces. Samples were gathered for each landrace by mixing equal weights from young leaves, from which DNA was extracted. We then estimated allelic frequencies in each DNA bulk based on fluorescent intensity ratio (FIR) between two alleles at each SNP using a two step-approach. We first tested either whether the DNA bulk was monomorphic or polymorphic according to the two FIR distributions of individuals homozygous for allele A or B, respectively. If the DNA bulk was polymorphic, we estimated its allelic frequency by using a predictive equation calibrated on FIR from DNA bulks with known allelic frequencies. Our approach: (i) gives accurate allelic frequency estimations that are highly reproducible across laboratories, (ii) protects against false detection of allele fixation within landraces. We estimated allelic frequencies of 23,412 SNPs in 156 landraces representing American and European maize diversity. Modified Roger’s genetic Distance between 156 landraces estimated from 23,412 SNPs and 17 simple sequence repeats using the same DNA bulks were highly correlated, suggesting that the ascertainment bias is low. Our approach is affordable, easy to implement and does not require specific bioinformatics support and laboratory equipment, and therefore should be highly relevant for large-scale characterization of genebanks for a wide range of species.


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