| TetR Regulated in vivo Repression Technology to Identify Conditional Gene Silencing in Genetically Engineerable Bacteria Using Vibrio cholerae Murine Infections as Model System
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Author:
Date:
2020-10-05
[Abstract] Investigation of bacterial gene regulation upon environmental changes is still a challenging task. For example, Vibrio cholerae, a pathogen of the human gastrointestinal tract, faces diverse transient conditions in different compartments upon oral ingestion. Genetic reporter systems have been demonstrated to be extremely powerful tools to unravel gene regulation events in complex conditions, but so far focused mainly on gene induction. Herein, we describe the TetR-controlled recombination-based in vivo expression technology TRIVET, which allows detection of gene silencing events. TRIVET resembles a modified variant of the in vivo expression technology (IVET) as well as recombination-based in vivo expression technology (RIVET), which were used to ...
[摘要] [摘要]研究细菌基因对环境变化的调控仍然是一项艰巨的任务。例如，人胃肠道的病原体霍乱弧菌在口服后会在不同的隔室中遇到各种短暂的状况。事实证明，遗传报告系统是揭示复杂条件下基因调控事件的极有力工具，但到目前为止，它主要集中在基因诱导上。在本文中，我们描述了基于TetR控制的重组的体内表达技术TRIVET，该技术可检测基因沉默事件。TRIVET类似于体内表达技术（IVET）以及基于重组的体内变异体 表达技术（RIVET），用于鉴定宿主定殖过程中几种细菌的条件基因诱导。像它的前辈一样，TRIVET是一个基于单细胞的报告系统，可以通过耐药谱的表型变化以时空方式分析细菌基因的阻遏。简而言之，无启动子的tetR （编码转录阻遏物TetR）可通过转座子诱变随机地整合到细菌基因组中，或通过同源重组在目标启动子的下游特异性整合到细菌基因组中。的TetR导致的去阻遏的转录表达的减少的TetR控制解离TNPR，这反过来又导致切除ö F A Ñ抗生素抗性盒（也称为RES-盒）和改变的电阻曲线可观察到的通过划线上氨苄青霉素和卡那霉素板。然后可以将这种改变量化为抗性和非抗性分离株之间的比例。此外，新引入的第二报道基因，promot erless ...
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| Probe-Seq: Method for RNA Sequencing of Specific Cell Types from Animal Tissue
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Author:
Date:
2020-09-20
[Abstract] Most organs and tissues are composed of many types of cells. To characterize cellular state, various transcription profiling approaches are currently available, including whole-tissue bulk RNA sequencing, single cell RNA sequencing (scRNA-Seq), and cell type-specific RNA sequencing. What is missing in this repertoire is a simple, versatile method for bulk transcriptional profiling of cell types for which cell type-specific genetic markers or antibodies are not readily available. We therefore developed Probe-Seq, which uses hybridization of gene-specific probes to RNA markers for isolation of specific types of cells, to enable downstream FACS isolation and bulk RNA sequencing. We show that this method can enable isolation and profiling of specific cell types from mouse retina, frozen human ...
[摘要] [摘要 ] 大多数器官和组织由许多类型的细胞组成。为了表征细胞状态，目前可以使用各种转录分析方法，包括全组织体RNA测序，单细胞RNA测序（scRNA -Seq）和特定于细胞类型的RNA测序。在此库中缺少的是一种简单，通用的方法，无法批量获得细胞类型的特定基因标记或抗体，因此无法批量转录。因此，我们开发了Probe-Seq，该探针使用基因特异性探针与RNA标记的杂交来分离特定类型的细胞，以实现下游FACS分离和大量RNA测序。我们表明，该方法可以实现从小鼠视网膜，冷冻人视网膜，果蝇中肠和发育中的雏鸡视网膜中分离和分析特定细胞类型的特征，这表明它对大多数生物很有用。
[背景技术 [ 0002 ] 在过去的二十年中，使用RNA-Seq和微阵列进行转录谱分析已在生物学研究中无处不在。分析现在是用来了解大多数生物体中细胞和细胞状态的主要工具之一。它被用于正常发育，异常发育和疾病的研究，并极大地扩展了我们对进化关系的理解。特别地，scRNA- Seq已经以前所未有的速度导致了新型细胞类型的鉴定（Picelli 等，2013；Jaitin 等，2014； Klein 等，2015； Macosko 等，2015）。为了更深入地了解这些新描述的细胞类型，一种无需转基因标记或特异性抗原即可将其分离的方法将大有裨益。尽管可以使用scRNA ...
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| Screening Method for CRISPR/Cas9 Inhibition of a Human DNA Virus: Herpes Simplex Virus
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Author:
Date:
2020-09-05
[Abstract] The efficiency of cleavage of individual CRISPR/Cas9-sgRNAs remains difficult to predict based on the CRISPR target sequence alone. Different intracellular environments (dependent on cell type or cell cycle state for example) may affect sgRNA efficiency by altering accessibility of genomic DNA through DNA modifications such as epigenetic marks and DNA-binding proteins (e.g., histones) as well as alteration of the chromatin state of genomic DNA within the nucleus.
We recently reported a multi-step screening method for the identification of efficient sgRNAs targeting the Herpes simplex virus (HSV-1) genome and reported a differential mechanism for viral inhibition by CRISPR-Cas9 in the latent versus lytic phase. The screening platform detailed in this protocol allows ...
[摘要] [摘要 ] 单独基于CRISPR靶序列仍难以预测单个CRISPR / Cas9-sgRNA的切割效率。不同的细胞内环境（例如，取决于细胞类型或细胞周期状态）可能会通过DNA修饰（例如表观遗传标记和DNA结合蛋白（例如组蛋白））和染色质状态的改变来改变基因组DNA的可及性，从而影响sgRNA效率。核内基因组DNA的标记。
我们recen TLY 报道的多步骤方法筛选用于有效sgRNAs靶向的识别的单纯疱疹病毒（HSV-1）的基因组，并报告为在潜对裂解病毒相抑制CRISPR-Cas9的差动机构。该协议中详述的筛选平台允许在无细胞系统中以及在病毒靶细胞（例如人包皮成纤维细胞）的背景下逐步测试切割效率，然后对CRISPR / sgRNA的作用进行功能测试病毒蛋白的表达，复制，和再活化。该策略可以容易地应用于其他靶细胞，例如多能干细胞衍生的人感觉神经元或其他人DNA病毒。
背景 ] 单纯疱疹病毒（HSV）是的一种嗜神经性DNA病毒疱疹病毒科家族引起终身和无法治愈感染在大多数人群的，并可能导致显著发病率和死亡率（Liesegang环等人，1989; Roizman 等人。，2013） ...
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