We would like to thank all the members of the Mitchell lab for helpful discussions. This work was supported by the Canadian Institutes of Health Research, the Canada Foundation for Innovation and the Ontario Ministry of Research and Innovation (operating and infrastructure grants held by JAM).

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笔者看了朱庇特的关于利益冲突的政策，并没有冲突披露。

CRISPR / Cas9介导的基因组编辑技术为基因改造一个简单，快捷，廉价的方法。这里详细生成和分析单等位基因缺失的增强功能性增强特性的方法发生在F1小鼠细胞单核苷酸多态性的优势的。这种类型的方法的优点是:1）单等位基因增强剂缺失不产生时的临界增强剂是从两个等位基因缺失， 即 ，在规定的基因导致细胞杀伤力的蛋白水平大大降低的或改变的发生的混杂影响表型; 2）如果单等位?...

转录调控元件由于异常的基因表达2是发展1和修改这些元素的过程中的基因表达的时空微调可导致疾病的关键。通过全基因组关联研究发现了许多疾病相关的区域是在非编码区，并有转录增强子3-4的功能。识别增强剂并将它们与它们调节是复杂的，因为它们通常位于从它们调节基因几千个碱基远并且可以以组织特异性方式5-6被激活的基因匹配。增强剂的预测通常是基于组蛋白修饰的标记，介体黏着复合物和细胞类型特异性转录结合因子7-10。预测增强剂的验证是最经常通过一个基于矢量的测定，其中所述增强剂激活报告基因11-12的表达进行。这些数据提供了v有关推测的增强子序列的调节潜力aluable信息，但不透露自己的功能其内生基因组范围内或识别它们调节的基因。基因组编辑充当一个强有力的工具来研究由失功能分析在它们的内源上下文转录调控元件的功能。 在基因组编辑，即CRISPR / Cas9基因组编辑系统的最新进展，有利于基因功能的研究。的CRISPR / Cas9系统易于使用和适应性对于许多生物系统。所述Cas9蛋白靶向于由导的RNA（gRNA）13中的基因组中的特定位点。所述SpCas9 / gRNA复杂扫描对其靶基因组序列的基因组中它必须是5&#39;到protospacer相邻基序（PAM）的序列，NGG 14-15。的gRNA到其目标，一个20个核苷酸（nt）的序列与gRNA互补的碱基配对，激活导致域金字塔之戒SpCas9核酸酶活Ë链断裂（DSB）3碱基的序列PAM的上游。特异性是通过在gRNA种子区域完全碱基配对来实现，所述6-12 nt下邻近于PAM;相反地，不匹配5&#39;种子的通常耐受16-17。引入的DSB可以修复或者由非同源末端连接（NHEJ）的DNA修复或同源性定向修复（HDR）mechanisms.NHEJ DNA修复往往造成在目标部位的几个碱基对，可以破坏的插入/缺失（插入缺失）的基因的开放阅读框（ORF）。以产生在基因组2 gRNAs，侧翼感兴趣的区域大的缺失，可以使用18-19。这种方法是对聚成基因座控制区或超增强剂它比常规增强剂9,18,20-22较大转录增强子的研究中特别有用的。 单等位基因缺失是研究转录顺 -regulation一个有价值的模型。观察到昌E在转录水平的增强子的单等位基因缺失之后关联到在基因调控该增强剂的不当两个等位基因的转录可能受影响的影响蜂窝健身时可能出现的混杂影响的作用。评估减少的表达是困难的但不区分野生型等位基因的删除的能力。此外，基因分型在每个等位基因缺失而不区分两个等位基因的能力是具有挑战性的，尤其是对大缺失&gt; 10kb的至1兆23，其中它是难以通过PCR扩增整个野生型区域。使用通过杂交小家鼠 129与小家鼠castaneus生成的F1 ES细胞的允许两个等位基因通过等位基因特异性PCR 18,24区别开来。在这些细胞中的基因组杂交便于等位基因特异缺失筛选和表达分析。上平均有一个SNP位这两个基因组之间的每一个125 bp的为表达和基因分型提供在引物设计的灵活性的分析。一种SNP的存在可以影响引物的熔化温度（T M）与靶实时定量PCR（qPCR的）扩增特异性允许两个等位基因25的歧视。此外，引物的3&#39;末端中的一个错配极大地影响DNA聚合酶从引物防止不期望的等位基因靶26的扩增延伸的能力。描述在下面的协议是使用CRISPR / Cas9基因组编辑系统（ 图1）大于1 kb的等位基因特异性增强缺失和随后的表达分析使用F1 ES细胞。 <img alt="图1" src="/files/ftp_upload/53552/53552fig1.jpg" /> 图1.增强删除使用CRISPR / Cas9研究 顺 -reg基因表达的ulation。（A）中由小家鼠 129和小家鼠castaneus之间的交叉产生的F1 ES细胞用于允许等位基因特异性缺失。 （B）中的两个导向的RNA（gRNA）用于诱导增强子区的一个大Cas9介导的缺失。 （C）的引物组被用于识别大的单-和双等位基因缺失。橙色引物是内引物，紫色引物外侧的引物和绿色的引物的gRNA侧翼引物。 （D）基因表达的变化是使用等位基因特异性qPCR的监控。俄罗斯足协表示相对荧光单位。 <a href="https://www.jove.com/files/ftp_upload/53552/53552fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

<table><tbody><tr><td>Phusion High-Fidelity DNA Polymerase</td><td>NEB</td><td>M0530S</td><td>high fidelity DNA polymerase used in gRNA assembly</td></tr><tr><td>Gibson Assembly Master Mix</td><td>NEB</td><td>E2611L</td><td></td></tr><tr><td>gRNA_Cloning Vector</td><td>Addgene</td><td>41824</td><td>A target sequence is cloned into this vector to create the gRNA plasmid</td></tr><tr><td>pCas9_GFP</td><td>Addgene</td><td>44719</td><td>Codon-optimized SpCas9 and EGFP co-expression plasmid</td></tr><tr><td>AflII</td><td>NEB</td><td>R0520S</td><td></td></tr><tr><td>EcoRI</td><td>NEB</td><td>R3101S</td><td></td></tr><tr><td>Neon Transfection System 100 &amp;micro;L Kit</td><td>Life Technologies</td><td>MPK10096</td><td>Microporator transfection technology</td></tr><tr><td>prepGEM</td><td>ZyGEM</td><td>PT10500</td><td>genomic DNA extraction reagent</td></tr><tr><td>Nucleo Spin Gel &amp;amp; PCR Clean-up</td><td>Macherey-Nagel</td><td>740609.5</td><td></td></tr><tr><td>High-Speed Plasmid Mini Kit</td><td>Geneaid</td><td>PD300</td><td></td></tr><tr><td>Maxi Plasmid Kit Endotoxin Free&amp;nbsp;</td><td>Geneaid</td><td>PME25</td><td></td></tr><tr><td>SYBR select mix for CFX</td><td>Life Technologies</td><td>4472942</td><td>qPCR reagent</td></tr><tr><td>iScript cDNA synthesis kit</td><td>Bio-rad</td><td>170-8891</td><td>Reverse transcription reagent</td></tr><tr><td>0.25% Trypsin with EDTA</td><td>Life Technologies</td><td>25200072</td><td></td></tr><tr><td>PBS without Ca/Mg&lt;sup&gt;2+&lt;/sup&gt;</td><td>Sigma</td><td>D8537</td><td></td></tr><tr><td>0.5 M EDTA</td><td>Bioshop</td><td>EDT111.500</td><td></td></tr><tr><td>HBSS</td><td>Life Technologies</td><td>14175095</td><td></td></tr><tr><td>1 M HEPES</td><td>Life Technologies</td><td>13630080</td><td></td></tr><tr><td>BSA fraction V (7.5%)</td><td>Life Technologies</td><td>15260037</td><td></td></tr><tr><td>Max Efficiency DH5&amp;alpha; competent cells</td><td>Invitrogen</td><td>18258012</td><td></td></tr><tr><td>FBS</td><td>ES cell qualified</td><td></td><td>FBS is subjected to a prior testing in mouse ES cells for pluripotency</td></tr><tr><td>DMSO</td><td>Sigma</td><td>D2650</td><td></td></tr><tr><td>Glutamax</td><td>Invitrogen</td><td>35050</td><td></td></tr><tr><td>DMEM</td><td>Life Technologies</td><td>11960069</td><td></td></tr><tr><td>Pencillin/Streptomycin</td><td>Invitrogen</td><td>15140</td><td></td></tr><tr><td>Sodium pyruvate</td><td>Invitrogen</td><td>11360</td><td></td></tr><tr><td>Non-essential aminoacid</td><td>Invitrogen</td><td>11140</td><td></td></tr><tr><td>&amp;beta;-mercaptoethanol</td><td>Sigma</td><td>M7522</td><td></td></tr><tr><td>96-well plate</td><td>Sarstedt</td><td>83.3924</td><td></td></tr><tr><td>Sealing tape</td><td>Sarstedt</td><td>95.1994</td><td></td></tr><tr><td>CoolCell LX</td><td>Biocision</td><td>BCS-405</td><td>alcohol-free cell freezing container</td></tr><tr><td>CHIR99021</td><td>Biovision</td><td>1748-5</td><td>Inhibitor for F1 ES cell culture</td></tr><tr><td>PD0325901</td><td>Invivogen</td><td>inh-pd32</td><td>Inhibitor for F1 ES cell culture</td></tr><tr><td>LIF</td><td>Chemicon</td><td>ESG1107</td><td>Inhibitor for F1 ES cell culture</td></tr></tbody></table>

generating crispr/cas9 mediated monoallelic deletions to study enhancer function in mouse embryonic stem cells

Enhancers control cell identity by regulating tissue-specific gene expression in a position and orientation independent manner. These enhancers are often located distally from the regulated gene in intergenic regions or even within the body of another gene. The position independent nature of enhancer activity makes it difficult to match enhancers with the genes they regulate. Deletion of an enhancer region provides direct evidence for enhancer activity and is the gold standard to reveal an enhancer's role in endogenous gene transcription. Conventional homologous recombination based deletion methods have been surpassed by recent advances in genome editing technology which enable rapid and precisely located changes to the genomes of numerous model organisms. CRISPR/Cas9 mediated genome editing can be used to manipulate the genome in many cell types and organisms rapidly and cost effectively, due to the ease with which Cas9 can be targeted to the genome by a guide RNA from a bespoke expression plasmid. Homozygous deletion of essential gene regulatory elements might lead to lethality or alter cellular phenotype whereas monoallelic deletion of transcriptional enhancers allows for the study of cis-regulation of gene expression without this confounding issue. Presented here is a protocol for CRISPR/Cas9 mediated deletion in F1 mouse embryonic stem (ES) cells (Mus musculus129 x Mus castaneus). Monoallelic deletion, screening and expression analysis is facilitated by single nucleotide polymorphisms (SNP) between the two alleles which occur on average every 125 bp in these cells.

这里所描述的协议使用的F1 ES细胞，研究基因表达的顺式 -regulation使用CRISPR / Cas9基因组编辑（ 图1）产生的单等位基因增强剂删除的细胞。用于基因分型和基因表达的gRNA和等位基因特异性引物的设计是在该方法的关键因素。每个等位基因特异性引物组必须通过qPCR进行验证，以确认等位基因特异性。等位基因特异性引物仅扩增各自的基因组DNA靶标是理想?...

Watch this Scientific Journal Video about Generating CRISPR/Cas9 Mediated Monoallelic Deletions to Study Enhancer Function in Mouse Embryonic Stem Cells at JoVE.com

Generating CRISPR/Cas9 Mediated Monoallelic Deletions to Study Enhancer Function in Mouse Embryonic Stem Cells

Experimental validation of enhancer activity is best approached by loss-of-function analysis. Presented here is an efficient protocol that uses CRISPR/Cas9 mediated deletion to study allele-specific regulation of gene transcription in F1 ES cells which contain a hybrid genome (Mus musculus129 x Mus castaneus).

生成CRISPR / Cas9介导的单等位基因缺失来研究小鼠胚胎干细胞功能增强

Enhancers control cell identity by regulating tissue-specific gene expression in a position and orientation independent manner. These enhancers are often ...

generating-crisprcas9-mediated-monoallelic-deletions-to-study

Research

JoVE Journal

Developmental Biology

14.1K 次观看.  University of Toronto. Experimental validation of enhancer activity is best approached by loss-of-function analysis. Presented here is an efficient protocol that uses CRISPR/Cas9 mediated deletion to study allele-specific regulation of gene transcription in F1 ES cells which contain a hybrid genome (Mus musculus129 x Mus castaneus).

视频: Generating CRISPR/Cas9 Mediated Monoallelic Deletions to Study Enhancer Function in Mouse Embryonic Stem Cells

Dissection of Enhancer Function Using Multiplex CRISPR-based Enhancer Interference in Cell Lines

Multiple enhancers often regulate a given gene, yet for most genes, it remains unclear which enhancers are necessary for gene expression, and how these enhancers combine to produce a transcriptional response. As millions of enhancers have been identified, high-throughput tools are needed to determine enhancer function on a genome-wide scale. Current methods for studying enhancer function include making genetic deletions using nuclease-proficient Cas9, but it is difficult to study the combinatorial effects of multiple enhancers using this technique, as multiple successive clonal cell lines must be generated. Here, we present Enhancer-i, a CRISPR interference-based method that allows for functional interrogation of multiple enhancers simultaneously at their endogenous loci. Enhancer-i makes use of two repressive domains fused to nuclease-deficient Cas9, SID and KRAB, to achieve enhancer deactivation via histone deacetylation at targeted loci. This protocol utilizes transient transfection of guide RNAs to enable transient inactivation of targeted regions and is particularly effective at blocking inducible transcriptional responses to stimuli in tissue culture settings. Enhancer-i is highly specific both in its genomic targeting and its effects on global gene expression. Results obtained from this protocol help to understand whether an enhancer is contributing to gene expression, the magnitude of the contribution, and how the contribution is affected by other nearby enhancers.

This protocol describes the steps needed to design and perform multiplexed targeting of enhancers with the deactivating fusion protein SID4X-dCas9-KRAB, also known as enhancer interference (Enhancer-i). This protocol enables the identification of enhancers that regulate gene expression and facilitates the dissection of relationships between enhancers regulating a common target gene.

基于多重 CRISPR 增强器的细胞系干扰增强功能解剖

Multiple enhancers often regulate a given gene, yet for most genes, it remains unclear which enhancers are necessary for gene expression, and how these ...

科研

遗传学

Structure-function Studies in Mouse Embryonic Stem Cells Using Recombinase-mediated Cassette Exchange

Gene engineering in mouse embryos or embryonic stem cells (mESCs) allows for the study of the function of a given protein. Proteins are the workhorses of the cell and often consist of multiple functional domains, which can be influenced by posttranslational modifications. The depletion of the entire protein in conditional or constitutive knock-out (KO) mice does not take into account this functional diversity and regulation. An mESC line and a derived mouse model, in which a docking site for FLPe recombination-mediated cassette exchange (RMCE) was inserted within the ROSA26 (R26) locus, was previously reported. Here, we report on a structure-function approach that allows for molecular dissection of the different functionalities of a multidomain protein. To this end, RMCE-compatible mice must be crossed with KO mice and then RMCE-compatible KO mESCs must be isolated. Next, a panel of putative rescue constructs can be introduced into the R26 locus via RMCE targeting. The candidate rescue cDNAs can be easily inserted between RMCE sites of the targeting vector using recombination cloning. Next, KO mESCs are transfected with the targeting vector in combination with an FLPe recombinase expression plasmid. RMCE reactivates the promoter-less neomycin-resistance gene in the ROSA26 docking sites and allows for the selection of the correct targeting event. In this way, high targeting efficiencies close to 100% are obtained, allowing for insertion of multiple putative rescue constructs in a semi-high throughput manner. Finally, a multitude of R26-driven rescue constructs can be tested for their ability to rescue the phenotype that was observed in parental KO mESCs. We present a proof-of-principle structure-function study in p120 catenin (p120ctn) KO mESCs using endoderm differentiation in embryoid bodies (EBs) as the phenotypic readout. This approach enables the identification of important domains, putative downstream pathways, and disease-relevant point mutations that underlie KO phenotypes for a given protein.

Proteins often contain multiple domains that can exert different cellular functions. Gene knock-outs (KO) do not consider this functional diversity. Here, we report a recombination-mediated cassette exchange (RMCE)-based structure-function approach in KO embryonic stem cells that allows for the molecular dissection of various functional domains or variants of a protein.

在小鼠胚胎干细胞结构功能研究使用重组酶介导的盒式交换

Gene engineering in mouse embryos or embryonic stem cells (mESCs) allows for the study of the function of a given protein. Proteins are the workhorses of ...

发育生物学

A Method to Study de novo Formation of Chromatin Domains

The organization and structure of chromatin domains are unique to individual cell lineages. Their misregulation might lead to a loss in cellular identity and/or disease. Despite tremendous efforts, our understanding of the formation and propagation of chromatin domains is still limited. Chromatin domains have been studied under steady-state conditions, which are not conducive to following the initial events during their establishment. Here, we present a method to inducibly reconstruct chromatin domains and follow their re-formation as a function of time. Although, first applied to the case of PRC2-mediated repressive chromatin domain formation, it could be easily adapted to other chromatin domains. The modification of and/or the combination of this method with genomics and imaging technologies will provide invaluable tools to study the establishment of chromatin domains in great detail. We believe that this method will revolutionize our understanding of how chromatin domains form and interact with each other.

A Method to Study de novo Formation of Chromatin Domains

This method is designed to follow formation of PRC2-mediated chromatin domains in cell lines, and the method can be adapted to many other systems.

色质域新形成研究方法

The organization and structure of chromatin domains are unique to individual cell lineages. Their misregulation might lead to a loss in cellular identity ...

Generation of Defined Genomic Modifications Using CRISPR-CAS9 in Human Pluripotent Stem Cells

Human pluripotent stem cells offer a powerful system to study gene function and model specific mutations relevant to disease. The generation of precise heterozygous genetic modifications is challenging due to CRISPR-CAS9 mediated indel formation in the second allele. Here, we demonstrate a protocol to help overcome this difficulty by using two repair templates in which only one expresses the desired sequence change, while both templates contain silent mutations to prevent re-cutting and indel formation. This methodology is most advantageous for gene editing coding regions of DNA to generate isogenic control and mutant human stem cell lines for studying human disease and biology. In addition, optimization of transfection and screening methodologies have been performed to reduce labor and cost of a gene editing experiment. Overall, this protocol is widely applicable to many genome editing projects utilizing the human pluripotent stem cell model.

This protocol provides a method to facilitate the generation of defined heterozygous or homozygous nucleotide changes using CRISPR-CAS9 in human pluripotent stem cells.

在人类多能干细胞中使用CRISPR-CAS9生成定义的基因组修饰

Human pluripotent stem cells offer a powerful system to study gene function and model specific mutations relevant to disease. The generation of precise ...

Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells

The bulk of the human genome (~98%) is comprised of non-coding sequences. Cis-regulatory elements (CREs) are non-coding DNA sequences that contain binding sites for transcriptional regulators to modulate gene expression. Alterations of CREs have been implicated in various diseases including cancer. While promoters and enhancers have been the primary CREs for studying gene regulation, very little is known about the role of silencer, which is another type of CRE that mediates gene repression. Originally identified as an adaptive immunity system in prokaryotes, CRISPR/Cas9 has been exploited to be a powerful tool for eukaryotic genome editing. Here, we present the use of this technique to delete an intronic silencer in the human RUNX1 gene and investigate the impacts on gene expression in OCI-AML3 leukemic cells. Our approach relies on electroporation-mediated delivery of two preassembled Cas9/guide RNA (gRNA) ribonucleoprotein (RNP) complexes to create two double-strand breaks (DSBs) that flank the silencer. Deletions can be readily screened by fragment analysis. Expression analyses of different mRNAs transcribed from alternative promoters help evaluate promoter-dependent effects. This strategy can be used to study other CREs and is particularly suitable for hematopoietic cells, which are often difficult to transfect with plasmid-based methods. The use of a plasmid- and virus-free strategy allows simple and fast assessments of gene regulatory functions.

Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells

Direct delivery of preassembled Cas9/guide RNA ribonucleoprotein complexes is a fast and efficient means for genome editing in hematopoietic cells. Here, we utilize this approach to delete a RUNX1 intronic silencer and examine the transcriptional responses in OCI-AML3 leukemic cells.

CRISPR/Cas9核糖核酸蛋白在急性骨髓性白血病细胞中的RUNX1电子消光器的转录作用研究

The bulk of the human genome (~98%) is comprised of non-coding sequences. Cis-regulatory elements (CREs) are non-coding DNA sequences that contain binding ...

CRISPR/Cas9-Mediated Highly Efficient Gene Targeting in Embryonic Stem Cells for Developing Gene-Manipulated Mouse Models

The CRISPR/Cas9 system has made it possible to develop genetically modified mice by direct genome editing using fertilized zygotes. However, although the efficiency in developing gene-knockout mice by inducing small indel mutation would be sufficient enough, the efficiency of embryo genome editing for making large-size DNA knock-in (KI) is still low. Therefore, in contrast to the direct KI method in embryos, gene targeting using embryonic stem cells (ESCs) followed by embryo injection to develop chimera mice still has several advantages (e.g., high throughput targeting in vitro, multi-allele manipulation, and Cre and flox gene manipulation can be carried out in a short period). In addition, strains with difficult-to-handle embryos in vitro, such as BALB/c, can also be used for ESC targeting. This protocol describes the optimized method for large-size DNA (several kb) KI in ESCs by applying CRISPR/Cas9-mediated genome editing followed by chimera mice production to develop gene-manipulated mouse models.

Here we present a protocol for developing genetically modified mouse models using embryonic stem cells, especially for large DNA knock-in (KI). This protocol is tuned up using CRISPR/Cas9 genome editing, resulting in significantly improved KI efficiency compared with the conventional homologous recombination-mediated linearized DNA targeting method.

CRISPR/Cas9介导的胚胎干细胞中的高效基因靶向，用于开发基因操纵的小鼠模型

The CRISPR/Cas9 system has made it possible to develop genetically modified mice by direct genome editing using fertilized zygotes. However, although the ...

Efficient Genome Editing of Mice by CRISPR Electroporation of Zygotes

With exceptional efficiency, accuracy, and ease, the CRISPR/Cas9 system has significantly improved genome editing in cell culture and lab animal experiments. When generating animal models, the electroporation of zygotes offers higher efficiency, simplicity, cost, and throughput as an alternative to the gold standard method of microinjection. Electroporation is also gentler, with higher viability, and reliably delivers Cas9/single-guide RNA (sgRNA) ribonucleoproteins (RNPs) into the zygotes of common laboratory mouse strains (e.g., C57BL/6J and C57BL/6N) that approaches 100% delivery efficiency. This technique enables insertion/deletion (indels) mutations, point mutations, the deletion of whole genes or exons, and small insertions in the range of 100-200 bp to insert LoxP or short tags like FLAG, HA, or V5. While constantly being improved, here we present the current state of CRISPR-EZ in a protocol that includes sgRNA production through in vitro transcription, embryo processing, RNP assembly, electroporation, and the genotyping of preimplantation embryos. A graduate-level researcher with minimal experience manipulating embryos can obtain genetically edited embryos in less than 1 week using this protocol. Here, we offer a straightforward, low-cost, efficient, high-capacity method that could be used with mouse embryos.

Here, we describe a simple technique intended for the efficient generation of genetically modified mice called CRISPR RNP Electroporation of Zygotes (CRISPR-EZ). This method delivers editing reagents by electroporation into embryos at an efficiency approaching 100%. This protocol is effective for point mutations, small genomic insertions, and deletions in mammalian embryos.

通过受精卵的CRISPR电穿孔对小鼠进行高效基因组编辑

With exceptional efficiency, accuracy, and ease, the CRISPR/Cas9 system has significantly improved genome editing in cell culture and lab animal ...

Lentiviral CRISPR/Cas9-Mediated Genome Editing for the Study of Hematopoietic Cells in Disease Models

Manipulating genes in hematopoietic stem cells using conventional transgenesis approaches can be time-consuming, expensive, and challenging. Benefiting from advances in genome editing technology and lentivirus-mediated transgene delivery systems, an efficient and economical method is described here that establishes mice in which genes are manipulated specifically in hematopoietic stem cells. Lentiviruses are used to transduce Cas9-expressing lineage-negative bone marrow cells with a guide RNA (gRNA) targeting specific genes and a red fluorescence reporter gene (RFP), then these cells are transplanted into lethally-irradiated C57BL/6 mice. Mice transplanted with lentivirus expressing non-targeting gRNA are used as controls. Engraftment of transduced hematopoietic stem cells are evaluated by flow cytometric analysis of RFP-positive leukocytes of peripheral blood. Using this method, ~90% transduction of myeloid cells and ~70% of lymphoid cells at 4 weeks after transplantation can be achieved. Genomic DNA is isolated from RFP-positive blood cells, and portions of the targeted site DNA are amplified by PCR to validate the genome editing. This protocol provides a high-throughput evaluation of hematopoiesis-regulatory genes and can be extended to a variety of mouse disease models with hematopoietic cell involvement.

Described are protocols for the highly efficient genome editing of murine hematopoietic stem and progenitor cells (HSPC) by the CRISPR/Cas9 system to rapidly develop mouse model systems with hematopoietic system-specific gene modifications.

Lentiviral CRISPR/Cas9介导基因组编辑，用于疾病模型中造血细胞的研究

Manipulating genes in hematopoietic stem cells using conventional transgenesis approaches can be time-consuming, expensive, and challenging. Benefiting ...

免疫与感染

Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific eukaryotic genome engineering. CRISPR/Cas9 is an inexpensive, facile, and efficient genome editing tool that allows genetic perturbation of genes and genetic elements. Here we present a simple methodology for CRISPR design, cloning, and delivery for the production of genomic deletions. In addition, we describe techniques for deletion, identification, and characterization. This strategy relies on cellular delivery of a pair of chimeric single guide RNAs (sgRNAs) to create two double strand breaks (DSBs) at a locus in order to delete the intervening DNA segment by non-homologous end joining (NHEJ) repair. Deletions have potential advantages as compared to single-site small indels given the efficiency of biallelic modification, ease of rapid identification by PCR, predictability of loss-of-function, and utility for the study of non-coding elements. This approach can be used for efficient loss-of-function studies of genes and genetic elements in mammalian cell lines.

CRISPR/Cas9 is a robust system to produce disruption of genes and genetic elements. Here we describe a protocol for the efficient creation of genomic deletions in mammalian cell lines using CRISPR/Cas9.

基因缺失在通过CRISPR / Cas9哺乳动物细胞系生成

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific ...

生物学

使用 CRISPR/Cas9 系统进行着丝粒相关 Protein-E 基因编辑

Generation of Centromere-Associated Protein-E CENP-E-/- Knockout Cell Lines using the CRISPR/Cas9 System

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system has emerged as a powerful tool for precise and efficient gene editing in a variety of organisms. Centromere-associated protein-E (CENP-E) is a plus-end-directed kinesin required for kinetochore-microtubule capture, chromosome alignment, and spindle assembly checkpoint. Although cellular functions of the CENP-E proteins have been well studied, it has been difficult to study the direct functions of CENP-E proteins using traditional protocols because CENP-E ablation usually leads to spindle assembly checkpoint activation, cell cycle arrest, and cell death. In this study, we have completely knocked out the CENP-E gene in human HeLa cells and successfully generated the CENP-E-/- HeLa cells using the CRISPR/Cas9 system.
Three optimized phenotype-based screening strategies were established, including cell colony screening, chromosome alignment phenotypes, and the fluorescent intensities of CENP-E proteins, which effectively improve the screening efficiency and experimental success rate of the CENP-E knockout cells. Importantly, CENP-E deletion results in chromosome misalignment, the abnormal location of the BUB1 mitotic checkpoint serine/threonine kinase B (BubR1) proteins, and mitotic defects. Furthermore, we have utilized the CENP-E knockout HeLa cell model to develop an identification method for CENP-E-specific inhibitors.
In this study, a useful approach to validate the specificity and toxicity of CENP-E inhibitors has been established. Moreover, this paper presents the protocols of CENP-E gene editing using the CRISPR/Cas9 system, which could be a powerful tool to investigate the mechanisms of CENP-E in cell division. Moreover, the CENP-E&#160;knockout cell line would contribute to the discovery and validation of CENP-E inhibitors, which have important implications for antitumor drug development, studies of cell division mechanisms in cell biology, and clinical applications.

作者聚焦:建立 CENP-E 敲除 HeLa 细胞 – 一种研究驱动蛋白 7 CENP-E 生物学及其抑制剂的新方法

This article reports the construction of centromere-associated protein-E (CENP-E) knockout cells using the CRISPR/Cas9 system and three phenotype-based screening strategies. We have utilized the CENP-E&#160;knockout cell line to establish a novel approach to validate the specificity and toxicity of the CENP-E inhibitors, which is useful for drug development and biological research.

使用 CRISPR/Cas9 系统生成着丝粒相关蛋白- E CENP-E-/- 敲除细胞系

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system has emerged as a powerful tool for precise and efficient gene editing ...