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1.
Sci Rep ; 14(1): 8159, 2024 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589623

RESUMO

Whole-genome sequencing (WGS) is currently making its transition from research tool into routine (clinical) diagnostic practice. The workflow for WGS includes the highly labor-intensive library preparations (LP), one of the most critical steps in the WGS procedure. Here, we describe the automation of the LP on the flowbot ONE robot to minimize the risk of human error and reduce hands-on time (HOT). For this, the robot was equipped, programmed, and optimized to perform the Illumina DNA Prep automatically. Results obtained from 16 LP that were performed both manually and automatically showed comparable library DNA yields (median of 1.5-fold difference), similar assembly quality values, and 100% concordance on the final core genome multilocus sequence typing results. In addition, reproducibility of results was confirmed by re-processing eight of the 16 LPs using the automated workflow. With the automated workflow, the HOT was reduced to 25 min compared to the 125 min needed when performing eight LPs using the manual workflow. The turn-around time was 170 and 200 min for the automated and manual workflow, respectively. In summary, the automated workflow on the flowbot ONE generates consistent results in terms of reliability and reproducibility, while significantly reducing HOT as compared to manual LP.


Assuntos
Lipopolissacarídeos , Robótica , Humanos , Reprodutibilidade dos Testes , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biblioteca Gênica , Sequenciamento Completo do Genoma , DNA , Fluxo de Trabalho
2.
Microb Genom ; 10(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38578268

RESUMO

Background. PCR amplification is a necessary step in many next-generation sequencing (NGS) library preparation methods [1, 2]. Whilst many PCR enzymes are developed to amplify single targets efficiently, accurately and with specificity, few are developed to meet the challenges imposed by NGS PCR, namely unbiased amplification of a wide range of different sizes and GC content. As a result PCR amplification during NGS library prep often results in bias toward GC neutral and smaller fragments. As NGS has matured, optimized NGS library prep kits and polymerase formulations have emerged and in this study we have tested a wide selection of available enzymes for both short-read Illumina library preparation and long fragment amplification ahead of long-read sequencing.We tested over 20 different hi-fidelity PCR enzymes/NGS amplification mixes on a range of Illumina library templates of varying GC content and composition, and find that both yield and genome coverage uniformity characteristics of the commercially available enzymes varied dramatically. Three enzymes Quantabio RepliQa Hifi Toughmix, Watchmaker Library Amplification Hot Start Master Mix (2X) 'Equinox' and Takara Ex Premier were found to give a consistent performance, over all genomes, that mirrored closely that observed for PCR-free datasets. We also test a range of enzymes for long-read sequencing by amplifying size fractionated S. cerevisiae DNA of average size 21.6 and 13.4 kb, respectively.The enzymes of choice for short-read (Illumina) library fragment amplification are Quantabio RepliQa Hifi Toughmix, Watchmaker Library Amplification Hot Start Master Mix (2X) 'Equinox' and Takara Ex Premier, with RepliQa also being the best performing enzyme from the enzymes tested for long fragment amplification prior to long-read sequencing.


Assuntos
DNA , Saccharomyces cerevisiae , Reação em Cadeia da Polimerase/métodos , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos
3.
Molecules ; 29(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38611841

RESUMO

The construction of a small molecule library that includes compounds with medium-sized rings is increasingly essential in drug discovery. These compounds are essential for identifying novel therapeutic agents capable of targeting "undruggable" targets through high-throughput and high-content screening, given their structural complexity and diversity. However, synthesizing medium-sized rings presents notable challenges, particularly with direct cyclization methods, due to issues such as transannular strain and reduced degrees of freedom. This review presents an overview of current strategies in synthesizing medium-sized rings, emphasizing innovative approaches like ring-expansion reactions. It highlights the challenges of synthesis and the potential of these compounds to diversify the chemical space for drug discovery, underscoring the importance of medium-sized rings in developing new bioactive compounds.


Assuntos
Descoberta de Drogas , Osteopatia , Biblioteca Gênica , Ciclização
4.
BMC Genomics ; 25(1): 364, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615000

RESUMO

Pseudoalteromonas viridis strain BBR56 was isolated from seawater at Dutungan Island, South Sulawesi, Indonesia. Bacterial DNA was isolated using Promega Genomic DNA TM050. DNA purity and quantity were assessed using NanoDrop spectrophotometers and Qubit fluorometers. The DNA library and sequencing were prepared using Oxford Nanopore Technology GridION MinKNOW 20.06.9 with long read, direct, and comprehensive analysis. High accuracy base calling was assessed with Guppy version 4.0.11. Filtlong and NanoPlot were used for filtering and visualizing the FASTQ data. Flye (2.8.1) was used for de novo assembly analysis. Variant calls and consensus sequences were created using Medaka. The annotation of the genome was elaborated by DFAST. The assembled genome and annotation were tested using Busco and CheckM. Herein, we found that the highest similarity of the BBR56 isolate was 98.37% with the 16 S rRNA gene sequence of P. viridis G-1387. The genome size was 5.5 Mb and included chromosome 1 (4.2 Mbp) and chromosome 2 (1.3 Mbp), which encoded 61 pseudogenes, 4 noncoding RNAs, 113 tRNAs, 31 rRNAs, 4,505 coding DNA sequences, 4 clustered regularly interspaced short palindromic repeats, 4,444 coding genes, and a GC content of 49.5%. The sequence of the whole genome of P. viridis BBR56 was uploaded to GenBank under the accession numbers CP072425-CP072426, biosample number SAMN18435505, and bioproject number PRJNA716373. The sequence read archive (SRR14179986) was successfully obtained from NCBI for BBR56 raw sequencing reads. Digital DNA-DNA hybridization results showed that the genome of BBR56 had the potential to be a new species because no other bacterial genomes were similar to the sample. Biosynthetic gene clusters (BGCs) were assessed using BAGEL4 and the antiSMASH bacterial version. The genome harbored diverse BGCs, including genes that encoded polyketide synthase, nonribosomal peptide synthase, RiPP-like, NRP-metallophore, hydrogen cyanide, betalactone, thioamide-NRP, Lant class I, sactipeptide, and prodigiosin. Thus, BBR56 has considerable potential for further exploration regarding the use of its secondary metabolite products in the human and fisheries sectors.


Assuntos
Pseudoalteromonas , Humanos , Pseudoalteromonas/genética , Pseudogenes , Biblioteca Gênica , DNA Bacteriano
5.
Nat Commun ; 15(1): 3199, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615009

RESUMO

The increasing availability of experimental and computational protein structures entices their use for function prediction. Here we develop an automated procedure to identify enzymes involved in metabolic reactions by assessing substrate conformations docked to a library of protein structures. By screening AlphaFold-modeled vitamin B6-dependent enzymes, we find that a metric based on catalytically favorable conformations at the enzyme active site performs best (AUROC Score=0.84) in identifying genes associated with known reactions. Applying this procedure, we identify the mammalian gene encoding hydroxytrimethyllysine aldolase (HTMLA), the second enzyme of carnitine biosynthesis. Upon experimental validation, we find that the top-ranked candidates, serine hydroxymethyl transferase (SHMT) 1 and 2, catalyze the HTMLA reaction. However, a mouse protein absent in humans (threonine aldolase; Tha1) catalyzes the reaction more efficiently. Tha1 did not rank highest based on the AlphaFold model, but its rank improved to second place using the experimental crystal structure we determined at 2.26 Å resolution. Our findings suggest that humans have lost a gene involved in carnitine biosynthesis, with HTMLA activity of SHMT partially compensating for its function.


Assuntos
Aldeído Liases , Frutose-Bifosfato Aldolase , Humanos , Animais , Camundongos , Frutose-Bifosfato Aldolase/genética , Catálise , Biblioteca Gênica , Glicina Hidroximetiltransferase/genética , Carnitina , Mamíferos
6.
PLoS One ; 19(4): e0298927, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38625992

RESUMO

INTRODUCTION: Dyadic care, which is the concurrent provision of care for a birthing person and their infant, is an approach that may improve disparities in postnatal health outcomes, but no synthesis of existing dyadic care studies has been conducted. This scoping review seeks to identify and summarize: 1) dyadic care studies globally, in which the birthing person-infant dyad are cared for together, 2) postnatal health outcomes that have been evaluated following dyadic care interventions, and 3) research and practice gaps in the implementation, dissemination, and effectiveness of dyadic care to reduce healthcare disparities. MATERIALS AND METHODS: Eligible studies will (1) include dyadic care instances for the birthing person and infant, and 2) report clinical outcomes for at least one member of the dyad or intervention outcomes. Studies will be excluded if they pertain to routine obstetric care, do not present original data, and/or are not available in English or Spanish. We will search CINAHL, Ovid (both Embase and Medline), Scopus, Cochrane Library, PubMed, Google Scholar, Global Health, Web of Science Core Collection, gray literature, and WHO regional databases. Screening will be conducted via Covidence and data will be extracted to capture the study design, dyad characteristics, clinical outcomes, and implementation outcomes. The risk of bias will be assessed using the Joanna Briggs Institute Critical Appraisal Tool. A narrative synthesis of the study findings will be presented. DISCUSSION: This scoping review will summarize birthing person-infant dyadic care interventions that have been studied and the evidence for their effectiveness. This aggregation of existing data can be used by healthcare systems working to improve healthcare delivery to their patients with the aim of reducing postnatal morbidity and mortality. Areas for future research will also be highlighted. TRAIL REGISTRATION: This review has been registered at Open Science Framework (OSF, https://osf.io/5fs6e/).


Assuntos
Academias e Institutos , Disparidades em Assistência à Saúde , Lactente , Feminino , Gravidez , Criança , Humanos , Bases de Dados Factuais , Biblioteca Gênica , Cuidado do Lactente , Literatura de Revisão como Assunto
7.
Genome Biol Evol ; 16(4)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38597156

RESUMO

De novo genes emerge from previously noncoding stretches of the genome. Their encoded de novo proteins are generally expected to be similar to random sequences and, accordingly, with no stable tertiary fold and high predicted disorder. However, structural properties of de novo proteins and whether they differ during the stages of emergence and fixation have not been studied in depth and rely heavily on predictions. Here we generated a library of short human putative de novo proteins of varying lengths and ages and sorted the candidates according to their structural compactness and disorder propensity. Using Förster resonance energy transfer combined with Fluorescence-activated cell sorting, we were able to screen the library for most compact protein structures, as well as most elongated and flexible structures. We find that compact de novo proteins are on average slightly shorter and contain lower predicted disorder than less compact ones. The predicted structures for most and least compact de novo proteins correspond to expectations in that they contain more secondary structure content or higher disorder content, respectively. Our experiments indicate that older de novo proteins have higher compactness and structural propensity compared with young ones. We discuss possible evolutionary scenarios and their implications underlying the age-dependencies of compactness and structural content of putative de novo proteins.


Assuntos
Dobramento de Proteína , Proteínas , Humanos , Proteínas/genética , Estrutura Secundária de Proteína , Biblioteca Gênica
8.
Bioinformatics ; 40(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38569896

RESUMO

MOTIVATION: Long-read sequencing technologies, an attractive solution for many applications, often suffer from higher error rates. Alignment of multiple reads can improve base-calling accuracy, but some applications, e.g. sequencing mutagenized libraries where multiple distinct clones differ by one or few variants, require the use of barcodes or unique molecular identifiers. Unfortunately, sequencing errors can interfere with correct barcode identification, and a given barcode sequence may be linked to multiple independent clones within a given library. RESULTS: Here we focus on the target application of sequencing mutagenized libraries in the context of multiplexed assays of variant effects (MAVEs). MAVEs are increasingly used to create comprehensive genotype-phenotype maps that can aid clinical variant interpretation. Many MAVE methods use long-read sequencing of barcoded mutant libraries for accurate association of barcode with genotype. Existing long-read sequencing pipelines do not account for inaccurate sequencing or nonunique barcodes. Here, we describe Pacybara, which handles these issues by clustering long reads based on the similarities of (error-prone) barcodes while also detecting barcodes that have been associated with multiple genotypes. Pacybara also detects recombinant (chimeric) clones and reduces false positive indel calls. In three example applications, we show that Pacybara identifies and correctly resolves these issues. AVAILABILITY AND IMPLEMENTATION: Pacybara, freely available at https://github.com/rothlab/pacybara, is implemented using R, Python, and bash for Linux. It runs on GNU/Linux HPC clusters via Slurm, PBS, or GridEngine schedulers. A single-machine simplex version is also available.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Software , Análise de Sequência de DNA/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biblioteca Gênica , Genótipo , Análise por Conglomerados
9.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38612639

RESUMO

Single-cell RNA sequencing (scRNA-seq) has emerged as a powerful technique for investigating biological heterogeneity at the single-cell level in human systems and model organisms. Recent advances in scRNA-seq have enabled the pooling of cells from multiple samples into single libraries, thereby increasing sample throughput while reducing technical batch effects, library preparation time, and the overall cost. However, a comparative analysis of scRNA-seq methods with and without sample multiplexing is lacking. In this study, we benchmarked methods from two representative platforms: Parse Biosciences (Parse; with sample multiplexing) and 10x Genomics (10x; without sample multiplexing). By using peripheral blood mononuclear cells (PBMCs) obtained from two healthy individuals, we demonstrate that demultiplexed scRNA-seq data obtained from Parse showed similar cell type frequencies compared to 10x data where samples were not multiplexed. Despite relatively lower cell capture affecting library preparation, Parse can detect rare cell types (e.g., plasmablasts and dendritic cells) which is likely due to its relatively higher sensitivity in gene detection. Moreover, a comparative analysis of transcript quantification between the two platforms revealed platform-specific distributions of gene length and GC content. These results offer guidance for researchers in designing high-throughput scRNA-seq studies.


Assuntos
Benchmarking , Leucócitos Mononucleares , Humanos , Biblioteca Gênica , Genômica , Análise de Sequência de RNA
10.
BMC Cancer ; 24(1): 490, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632528

RESUMO

BACKGROUND: Patients with rheumatologic preexisting autoimmune disease (PAD) have not been enrolled in clinical trials of immune checkpoint inhibitors (ICIs). Therefore, the risks and benefits of ICI therapy in such patients are unclear. Herein, we investigated the safety and efficacy of ICIs in rheumatologic PAD patients through a meta-analysis. METHODS: The PubMed, Cochrane Library, Embase and Web of Science databases were searched for additional studies. We analyzed the following data through Stata software: incidence of total irAEs (TirAEs), rate of flares, incidence of new on-set irAEs, rate of discontinuation, objective response rate (ORR) and disease control rate (DCR). RESULTS: We identified 23 articles including 643 patients with rheumatologic PAD. The pooled incidences of TirAEs, flares and new-onset irAEs were 64% (95% CI 55%-72%), 41% (95% CI 31%-50%), and 33% (95% CI 28%-38%), respectively. In terms of severity, the incidences were 7% (95% CI 2%-14%) for Grade 3-4 flares and 12% (95% CI 9%-15%) for Grade 3-4 new-onset irAEs. Patients with RA had a greater risk of flares than patients with other rheumatologic PADs did (RR = 1.35, 95% CI 1.03-1.77). The ORR and DCR were 30% and 44%, respectively. Baseline anti-rheumatic treatment was not significantly associated with the frequency of flares (RR = 1.05, 95% CI 0.63-1.77) or the ORR (RR = 0.45, 95% CI 0.12-1.69). CONCLUSIONS: Patients with rheumatologic PAD, particularly those with RA, are susceptible to relapse of their rheumatologic disease following ICI therapy. ICIs are also effective for treating rheumatologic PAD patients. PROSPECTIVE REGISTER OF SYSTEMATIC REVIEWS (PROSPERO): number CRD 42,023,439,702.


Assuntos
Artrite Reumatoide , Doenças Autoimunes , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico , Bases de Dados Factuais , Biblioteca Gênica
11.
BMC Bioinformatics ; 25(1): 154, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637756

RESUMO

BACKGROUND: High-throughput sequencing is a powerful tool that is extensively applied in biological studies. However, sequencers may produce low-quality bases, leading to ambiguous bases, 'N's. PCR duplicates introduced in library preparation are conventionally removed in genomics studies, and several deduplication tools have been developed for this purpose. Two identical reads may appear different due to ambiguous bases and the existing tools cannot address 'N's correctly or efficiently. RESULTS: Here we proposed and implemented TrieDedup, which uses the trie (prefix tree) data structure to compare and store sequences. TrieDedup can handle ambiguous base 'N's, and efficiently deduplicate at the level of raw sequences. We also reduced its memory usage by approximately 20% by implementing restrictedDict in Python. We benchmarked the performance of the algorithm and showed that TrieDedup can deduplicate reads up to 270-fold faster than pairwise comparison at a cost of 32-fold higher memory usage. CONCLUSIONS: The TrieDedup algorithm may facilitate PCR deduplication, barcode or UMI assignment, and repertoire diversity analysis of large-scale high-throughput sequencing datasets with its ultra-fast algorithm that can account for ambiguous bases due to sequencing errors.


Assuntos
Algoritmos , Software , Genômica , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA
12.
Appl Microbiol Biotechnol ; 108(1): 305, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38643427

RESUMO

Non-equilibrium (NEQ) alchemical free energy calculations are an emerging tool for accurately predicting changes in protein folding free energy resulting from amino acid mutations. In this study, this method in combination with the Rosetta ddg monomer tool was applied to predict more thermostable variants of the polyethylene terephthalate (PET) degrading enzyme DuraPETase. The Rosetta ddg monomer tool efficiently enriched promising mutations prior to more accurate prediction by NEQ alchemical free energy calculations. The relative change in folding free energy of 96 single amino acid mutations was calculated by NEQ alchemical free energy calculation. Experimental validation of ten of the highest scoring variants identified two mutations (DuraPETaseS61M and DuraPETaseS223Y) that increased the melting temperature (Tm) of the enzyme by up to 1 °C. The calculated relative change in folding free energy showed an excellent correlation with experimentally determined Tm resulting in a Pearson's correlation coefficient of r = - 0.84. Limitations in the prediction of strongly stabilizing mutations were, however, encountered and are discussed. Despite these challenges, this study demonstrates the practical applicability of NEQ alchemical free energy calculations in prospective enzyme engineering projects. KEY POINTS: • Rosetta ddg monomer enriches stabilizing mutations in a library of DuraPETase variants • NEQ free energy calculations accurately predict changes in Tm of DuraPETase • The DuraPETase variants S223Y, S42M, and S61M have increased Tm.


Assuntos
Aminoácidos , Polietilenotereftalatos , Estudos Prospectivos , Biblioteca Gênica , Mutação
13.
Methods Mol Biol ; 2787: 183-197, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38656490

RESUMO

PacBio long-read sequencing is a third-generation technology that generates long reads up to 20 kilobases (kb), unlike short-read sequencing instruments that produce up to 600 bases. Long-read sequencing is particularly advantageous in higher organisms, such as humans and plants, where repetitive regions in the genome are more abundant. The PacBio long-read sequencing uses a single molecule, real-time approach where the SMRT cells contain several zero-mode waveguides (ZMWs). Each ZMW contains a single DNA molecule bound by a DNA polymerase. All ZMWs are flushed with deoxy nucleotides with a fluorophore specific to each nucleotide. As the sequencing proceeds, the detector detects the wavelength of the fluorescence and the nucleotides are read in real-time. This chapter describes the sample and library preparation for PacBio long-read sequencing for grapevine.


Assuntos
Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Vitis , Vitis/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , DNA de Plantas/genética , Genoma de Planta
14.
Nat Commun ; 15(1): 3447, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658554

RESUMO

Achieving cost-competitive bio-based processes requires development of stable and selective biocatalysts. Their realization through in vitro enzyme characterization and engineering is mostly low throughput and labor-intensive. Therefore, strategies for increasing throughput while diminishing manual labor are gaining momentum, such as in vivo screening and evolution campaigns. Computational tools like machine learning further support enzyme engineering efforts by widening the explorable design space. Here, we propose an integrated solution to enzyme engineering challenges whereby ML-guided, automated workflows (including library generation, implementation of hypermutation systems, adapted laboratory evolution, and in vivo growth-coupled selection) could be realized to accelerate pipelines towards superior biocatalysts.


Assuntos
Biocatálise , Engenharia de Proteínas , Engenharia de Proteínas/métodos , Enzimas/metabolismo , Enzimas/genética , Enzimas/química , Aprendizado de Máquina , Evolução Molecular Direcionada/métodos , Automação , Biblioteca Gênica
15.
STAR Protoc ; 5(1): 102908, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38461411

RESUMO

Processing dissociated cells for transcriptomics is challenging when targeting small brain structures, like brainstem nuclei, where cell yield may be low. Here, we present a protocol for dissecting, dissociating, and cryopreserving mouse brainstem that allows asynchronous sample collection and downstream processing of cells obtained from brainstem tissue in neonatal mice. Although we demonstrate this protocol with the isolated preBötzinger complex and downstream SmartSeq3 cDNA library preparation, it could be readily adapted for other brainstem areas and library preparation approaches.


Assuntos
Tronco Encefálico , Análise da Expressão Gênica de Célula Única , Camundongos , Animais , Núcleo Celular , Perfilação da Expressão Gênica/métodos , Biblioteca Gênica
16.
Sci Rep ; 14(1): 7121, 2024 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-38531981

RESUMO

Citrus canker is a bacterial disease caused by Xanthomonas citri subsp. citri (Xcc) that affects the citrus industry worldwide. Hrp pili subunits (HrpE), an essential component of Type III secretion system (T3SS) bacteria, play a crucial role in the pathogenesis of Xcc by transporting effector proteins into the host cell and causing canker symptoms. Therefore, development of antibodies that block HrpE can suppress disease progression. In this study, a specific scFv detecting HrpE was developed using phage display technique and characterized using sequencing, ELISA, Western blotting, and molecular docking. In addition, a plant expression vector of pCAMBIA-scFvH6 was constructed and agroinfiltrated into Nicotiana tabacum cv. Samson leaves. The hypersensitive response (HR) in the leaves of transformed and non-transformed plants was evaluated by inoculating leaves with Xcc. After three rounds of biopanning of the phage library, a specific human scFv antibody, named scFvH6, was identified that showed high binding activity against HrpE in ELISA and Western blotting. Molecular docking results showed that five intermolecular hydrogen bonds are involved in HrpE-scFvH6 interaction, confirming the specificity and high binding activity of scFvH6. Successful transient expression of pCAMBIA-scFvH6 in tobacco leaves was verified using immunoassay tests. The binding activity of plant-produced scFvH6 to detect HrpE in Western blotting and ELISA was similar to that of bacterial-produced scFvH6 antibody. Interestingly, tobacco plants expressing scFvH6 showed a remarkable reduction in HR induced by Xcc compared with control plants, so that incidence of necrotic lesions was significantly higher in non-transformed controls (≥ 1.5 lesions/cm2) than in the plants producing scFvH6 (≤ 0.5 lesions/cm2) after infiltration with Xcc inoculum. Our results revealed that the expression of scFvH6 in tobacco leaves can confer resistance to Xcc, indicating that this approach could be considered to provide resistance to citrus bacterial canker disease.


Assuntos
Citrus , Xanthomonas , Humanos , Simulação de Acoplamento Molecular , Xanthomonas/genética , Citrus/microbiologia , Biblioteca Gênica , Doenças das Plantas/microbiologia , Folhas de Planta/metabolismo
17.
Sci Adv ; 10(13): eadk1200, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38552012

RESUMO

Ferroptosis is a form of iron-dependent, lipid peroxidation-driven regulatory cell death that has been implicated in the pathogenesis of multiple diseases, including organ injury, ischemia/reperfusion, and neurodegenerative diseases. However, inhibitors that directly and specifically target ferroptosis are not yet available. Here, we identify the compound AS-252424 (AS) as a potent ferroptosis inhibitor through kinase inhibitor library screening. Our results show that AS effectively inhibits lipid peroxidation and ferroptosis in both human and mouse cells. Mechanistically, AS directly binds to the glutamine 464 of ACSL4 to inhibit its enzymatic activity, resulting in the suppression of lipid peroxidation and ferroptosis. By using nanoparticle-based delivery systems, treatment with AS-loaded nanoparticles effectively alleviate ferroptosis-mediated organ injury in mouse models, including kidney ischemia/reperfusion injury and acute liver injury (ALI). Thus, our results identify that AS is a specific and targeted inhibitor of ACSL4 with remarkable antiferroptosis function, providing a potential therapeutic for ferroptosis-related diseases.


Assuntos
Ferroptose , Humanos , Animais , Camundongos , Morte Celular , Modelos Animais de Doenças , Biblioteca Gênica , Isquemia
18.
PLoS Comput Biol ; 20(3): e1011937, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38489348

RESUMO

The tracking of lineage frequencies via DNA barcode sequencing enables the quantification of microbial fitness. However, experimental noise coming from biotic and abiotic sources complicates the computation of a reliable inference. We present a Bayesian pipeline to infer relative microbial fitness from high-throughput lineage tracking assays. Our model accounts for multiple sources of noise and propagates uncertainties throughout all parameters in a systematic way. Furthermore, using modern variational inference methods based on automatic differentiation, we are able to scale the inference to a large number of unique barcodes. We extend this core model to analyze multi-environment assays, replicate experiments, and barcodes linked to genotypes. On simulations, our method recovers known parameters within posterior credible intervals. This work provides a generalizable Bayesian framework to analyze lineage tracking experiments. The accompanying open-source software library enables the adoption of principled statistical methods in experimental evolution.


Assuntos
Ensaios de Triagem em Larga Escala , Software , Teorema de Bayes , Análise de Sequência de DNA , Biblioteca Gênica
19.
Methods Mol Biol ; 2774: 135-152, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38441763

RESUMO

Sequencing-based, massively parallel genetic assays have enabled simultaneous characterization of the genotype-phenotype relationships for libraries encoding thousands of unique protein variants. Since plasmid transfection and lentiviral transduction have characteristics that limit multiplexing with pooled libraries, we developed a mammalian synthetic biology platform that harnesses the Bxb1 bacteriophage DNA recombinase to insert single promoterless plasmids encoding a transgene of interest into a pre-engineered "landing pad" site within the cell genome. The transgene is expressed behind a genomically integrated promoter, ensuring only one transgene is expressed per cell, preserving a strict genotype-phenotype link. Upon selecting cells based on a desired phenotype, the transgene can be sequenced to ascribe each variant a phenotypic score. We describe how to create and utilize landing pad cells for large-scale, library-based genetic experiments. Using the provided examples, the experimental template can be adapted to explore protein variants in diverse biological problems within mammalian cells.


Assuntos
Bacteriófagos , Genômica , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Biblioteca Gênica , Bioensaio , Proteínas Mutantes , Mamíferos
20.
Sci Rep ; 14(1): 6756, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514891

RESUMO

Transposon directed insertion-site sequencing (TraDIS), a variant of transposon insertion sequencing commonly known as Tn-Seq, is a high-throughput assay that defines essential bacterial genes across diverse growth conditions. However, the variability between laboratory environments often requires laborious, time-consuming modifications to its protocol. In this technical study, we aimed to refine the protocol by identifying key parameters that can impact the complexity of mutant libraries. Firstly, we discovered that adjusting electroporation parameters including transposome concentration, transposome assembly conditions, and cell densities can significantly improve the recovery of viable mutants for different Escherichia coli strains. Secondly, we found that post-electroporation conditions, such as recovery time and the use of different mediums for selecting mutants may also impact the complexity of viable mutants in the library. Finally, we developed a simplified sequencing library preparation workflow based on a Nextera-TruSeq hybrid design where ~ 80% of sequenced reads correspond to transposon-DNA junctions. The technical improvements presented in our study aim to streamline TraDIS protocols, making this powerful technique more accessible for a wider scientific audience.


Assuntos
Elementos de DNA Transponíveis , Genes Bacterianos , Mutagênese Insercional , Elementos de DNA Transponíveis/genética , Análise Custo-Benefício , Sequência de Bases , Escherichia coli/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biblioteca Gênica
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