Ce travail a été soutenu par un financement de l&#39;Institut de recherche et d&#39;Morgridge l&#39;Université du Wisconsin Foundation. Nous tenons à remercier Krista Eastman pour son assistance éditoriale.

<ol>
	<li>Tang, F., Barbacioru, C., Wang, Y., Nordman, E., Lee, C., Xu, N., Wang, X., Bodeau, J., Tuch, B. B., Siddiqui, A., Lao, K., Surani, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mRNA-Seq+whole-transcriptome+analysis+of+a+single+cell.">mRNA-Seq whole-transcriptome analysis of a single cell.</a> Nature Methods. 6, 377-382 (2009).</li><li>Armour, C. D., Castle, J. C., Chen, R., Babak, T., Loerch, P., Jackson, S., Shah, J. K., Dey, J., Rohl, C. A., Johnson, J. M., Raymond, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Digital+transcriptome+profiling+using+selective+hexamer+priming+for+cDNA+synthesis.">Digital transcriptome profiling using selective hexamer priming for cDNA synthesis.</a> Nature Methods. 6, 647-649 (2009).</li><li>Mortazavi, A., Williams, B. A., McCue, K., Schaeffer, L., Wold, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+and+quantifying+mammalian+transcriptomes+by+RNA-Seq.">Mapping and quantifying mammalian transcriptomes by RNA-Seq.</a> Nature Methods. 5, 621-628 (2008).</li><li>Mamanova, L., Andrews, R. M., James, K. D., Sheridan, E. M., Ellis, P. D., Langford, C. F., Ost, T. W., Collins, J. E., Turner, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=FRT-seq+amplification-free,+strand-specific+transcriptome+sequencing.">FRT-seq amplification-free, strand-specific transcriptome sequencing.</a> Nature Methods. 5, 130-132 (2010).</li><li>Sengupta, S., Ruotti, V., Bolin, J., Elwell, A., Hernandez, A., Thomson, J., Stewart, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+consistent,+fully+representative+mRNA-Seq+libraries+from+ten+nanograms+of+total+RNA.">Highly consistent, fully representative mRNA-Seq libraries from ten nanograms of total RNA.</a> Biotechniques. 49, 898-904 (2010).</li><li>Langmead, B., Trapnell, C., Pop, M., Salzberg, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrafast+and+memory-efficient+alignment+of+short+DNA+sequences+to+the+human+genome.">Ultrafast and memory-efficient alignment of short DNA sequences to the human genome.</a> Genome. Biology. 10, R25-R25 (2009).</li><li>Li, B., Ruotti, V., Stewart, R. M., Thomson, J. A., Dewey, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA-Seq+gene+expression+estimation+with+read+mapping+uncertainty.">RNA-Seq gene expression estimation with read mapping uncertainty.</a> Biotechniques. 26, 493-500 (2010).</li><li>Thomson, J. A., Itskovitz-Eldor, J., Shapiro, S. S., Waknitz, M. A., Swiergiel, J. J., Marshall, V. S., Jones, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+stem+cell+lines+derived+from+human+blastocysts.">Embryonic stem cell lines derived from human blastocysts.</a> Science. 282, 1145-1147 (1998).</li></ol>

Les auteurs révéler que JAT est un fondateur, stockowner, consultant et membre du conseil de la dynamique cellulaire international (CDI). Il est aussi conseiller scientifique et a des intérêts financiers dans Ventures II Tactiques de cellules souches.

Les protocoles actuels pour rendre les bibliothèques fin jumelé nécessitent entre 1 ug de 9 à 2,5 mg 10 montant de départ de l&#39;ARN total. Ici, nous présentons nos amplification linéaire basée T7 (T7LA) méthode pour préparer à la fois simple lecture et les bibliothèques jumelé Illumina fin de séquençage et montrent que cette méthode permet la génération de bibliothèques d&#39;aussi peu que 10 ng d&#39;ARN total, la production de données qui est comparable à celle de minimalement amplifiées (MinAmp) fabriqués à partir de 1000 bibliothèques du matériel fois plus de départ (10 ug d&#39;ARN totaux). Les 10 bibliothèques ng non seulement identifier similaires du nombre total de gènes, mais aussi de produire des signatures d&#39;expression génique qui sont similaires (figures 3a et b). Par ailleurs, à la fois la seule fin de lecture et des bibliothèques jumelé produites par la méthode T7LA sont très semblables les uns aux autres (figure 3C), qui permet aux chercheurs de comparer les données générées par les bibliothèques à partir de deux protocoles. Depuis ces bibliothèques ont été préparés à partir d&#39;embryons humains ARN des cellules souches, nous avons cherchépour les 30 gènes de cellules souches spécifiques entre les bibliothèques et constatent que la quasi-totalité de ces gènes (93-100%) sont identifiés par les bibliothèques fabriqués à partir d&#39;au moins 10 ng d&#39;ARN total de départ (figure 4), validant ainsi notre protocole. Nous croyons que notre protocole serait très utile pour les chercheurs, en particulier dans des circonstances telles que des cellules d&#39;écoulement triés ou laser micro-disséqués tissus où le matériel de départ est limitant. Dans de telles circonstances, notre protocole permettrait la génération de données d&#39;expression génique comparables aux bibliothèques fabriqués à partir de beaucoup plus grande quantité de départ, car notre protocole produit des profils d&#39;expression comparables à travers au moins 3 ordres de grandeur de l&#39;ARN de départ.

<table border="1"><tbody><tr><td> Société </td><td> Kit / Réactif </td><td> Catalogue # </td><td> Commentaires spéciales </td></tr><tr><td> Ambion </td><td> La fragmentation de réactifs </td><td> AM8740 </td><td></td></tr><tr><td> Ambion </td><td> L&#39;acrylamide Liner </td><td> AM9520 </td><td></td></tr><tr><td> Ambion </td><td> Megascript T7 Kit </td><td> AM1334 </td><td></td></tr><tr><td> Ambion </td><td> DEPC non traités eau sans nucléase </td><td> AM9932 </td><td></td></tr><tr><td> Fermentas </td><td> dNTP jeu </td><td> R0181 </td><td></td></tr><tr><td> Fermentas </td><td> dNTP méthylés </td><td> R0431 </td><td> Pour préparation d&#39;échantillon simple lecture seule </td></tr><tr><td> Illumina </td><td> TruSeq SR Cluster Génération kit v5 </td><td> GD-203-5001 </td><td> Pour préparation d&#39;échantillon simple lecture seule </td></tr><tr><td> Illumina </td><td> TruSeq Seq Kit v5 36 cycles </td><td> FC-104-5001 </td><td></td></tr><tr><td> Illumina </td><td> Chip Seq Sample Prep Kit </td><td> IP-102-1001 </td&gt; <td> Pour préparation d&#39;échantillon simple lecture seule. Peut être remplacé par l&#39;ONE échantillon d&#39;ADN de préparation Mix Master Set 1 Cat # E6040S </td></tr><tr><td> Illumina </td><td> TruSeq PE Cluster Génération kit v5 </td><td> PE-203-5001 </td><td> Pour de préparation fin échantillon apparié ne </td></tr><tr><td> Illumina </td><td> Jumelés échantillon Fin Prep Kit </td><td> PE-102-1001 </td><td> Pour de préparation fin échantillon apparié ne </td></tr><tr><td> Invitrogen </td><td> 1kb, plus l&#39;échelle </td><td> 10787-018 </td><td></td></tr><tr><td> Invitrogen </td><td> E. coli RNase H </td><td> 18021-014 </td><td></td></tr><tr><td> Invitrogen </td><td> Rnase Out </td><td> 10777-019 </td><td></td></tr><tr><td> Invitrogen </td><td> Buffer brin deuxième 5x </td><td> 10812-014 </td><td></td></tr><tr><td> Invitrogen </td><td> Polymérase ADN de E. coli </td><td> 18010-017 </td><td></td></tr><tr><td> Invitrogen </td><td> SYBR E-gel sûre 2% </td><td> G521802 </td><td></td></tr><tr><td> Invitrogen </td><td> Exposant que jeII (avec 5X FS tampon et DTT 0,1 M) </td><td> 18080-085 </td><td></td></tr><tr><td> Invitrogen </td><td> Trizol </td><td> 12183555 </td><td></td></tr><tr><td> Invitrogen </td><td> ARN test quibit kit </td><td> Q32852 </td><td></td></tr><tr><td> Invitrogen </td><td> ADNdb HS qubit test kit </td><td> Q32851 </td><td></td></tr><tr><td> Invitrogen </td><td> E. coli ADN ligase </td><td> 18052-019 </td><td></td></tr><tr><td> Invitrogen </td><td> ADN polymérase T4 </td><td> 18005-025 </td><td></td></tr><tr><td> Invitrogen </td><td> Ultra pur Dnase Rnase l&#39;eau </td><td> 10977-015 </td><td></td></tr><tr><td> Invitrogen </td><td> Superscript II double brin kit de synthèse d&#39;ADNc </td><td> 11917-020 </td><td></td></tr><tr><td> Invitrogen </td><td> Amorce aléatoire (Invitrogen) </td><td> 48190-011 </td><td> Pour de préparation fin échantillon apparié ne </td></tr><tr><td> IDT </td><td> Not1Nonamer amorce B </td><td> N / A </td><td> Pour lire Simple Samexemple de préparation ne </td></tr><tr><td> IDT </td><td> Oligo dT T7 </td><td> N / A </td><td></td></tr><tr><td> ONE </td><td> Not 1 kit de digestion </td><td> R0189S </td><td> Pour préparation d&#39;échantillon simple lecture seule </td></tr><tr><td> Qiagen </td><td> Rneasy MinElute kit </td><td> 74204 </td><td></td></tr><tr><td> Qiagen </td><td> RNeasy Mini Kit (50) </td><td> 74104 </td><td></td></tr><tr><td> Qiagen </td><td> Kit de purification de gel </td><td> 28604 </td><td></td></tr><tr><td> Qiagen </td><td> Dnase jeu </td><td> 79254 </td><td></td></tr><tr><td> Qiagen </td><td> Rneasy MinElute kit </td><td> 74204 </td><td></td></tr><tr><td> Zymo recherche </td><td> L&#39;ADN propre et concentrateur (250X) </td><td> D4014 </td><td></td></tr></tbody></table>

single read and paired end mrna-seq illumina libraries from 10 nanograms total rna

Séquençage du transcriptome entier par l&#39;ARNm-Seq est maintenant largement utilisée pour effectuer l&#39;expression génique globale, la mutation, l&#39;allèle spécifique d&#39;expression et d&#39;autres analyses du génome entier. ARNm-Seq ouvre même la porte pour l&#39;analyse de l&#39;expression du gène de la non-séquencé les génomes. ARNm-Seq offre une sensibilité élevée, une large gamme dynamique et permet de mesurer le nombre de copies transcription dans un échantillon. Analyseur d&#39;Illumina génome effectue le séquençage d&#39;un grand nombre (&gt; 10 7) de la séquence relativement courte lit (&lt;150 pb). La «fin jumelé&quot; approche, dans laquelle une seule lecture longue est séquencé à ses deux extrémités, permet de suivre les jonctions d&#39;épissage alternatif , insertions et suppressions, et est utile pour l&#39;assemblage de novo du transcriptome. L&#39;un des défis majeurs auxquels sont confrontés les chercheurs est une quantité limitée de matériau de départ. Par exemple, dans des expériences où les cellules sont récoltées par laser de micro-dissection, disponible à partir d&#39;ARN totaux may mesure en nanogrammes. Préparation de l&#39;ARNm-Seq bibliothèques à partir de ces échantillons ont été décrites 1, 2, mais implique une quantité importante d&#39;amplification PCR qui peuvent introduire des biais. Autres ARN-Seq procédures de construction de bibliothèque avec un minimum d&#39;amplification PCR ont été publiés 3, 4, mais exigent des quantités microgramme de l&#39;ARN total de départ. Nous décrivons ici un protocole pour la plateforme Illumina Genome Analyzer II pour l&#39;ARNm-Seq séquençage pour la préparation de la bibliothèque qui évite significative l&#39;amplification par PCR et ne requiert que 10 nanogrammes d&#39;ARN total. Bien que ce protocole a été décrit précédemment et validés pour une seule fin de séquençage 5, où il a été montré pour produire des bibliothèques sans introduire de biais directionnel amplification significative, il est ici de valider encore pour être utilisé comme un protocole de fin appariées. Nous amplifier sélectivement les ARN messagers polyadénylé de commencer ARN total en utilisant la T7 basée Eberwine méthode d&#39;amplification linéaire, inventé &quot;T7LA &quot;(T7 linéaires d&#39;amplification). Le amplifié ARNm poly-A sont fragmentés, une transcription inverse et l&#39;adaptateur ligaturés pour produire la bibliothèque séquençage final. Pour les deux courses seule fin de lecture et appariés, les séquences sont mappés à l&#39;homme du transcriptome 6 et normalisée de sorte que les données de plusieurs exécutions peuvent être comparés. Nous rapportons la mesure d&#39;expression génique dans des unités de transcriptions par million (TPM), qui est une mesure supérieure à RPKM lorsque l&#39;on compare les échantillons 7.

Watch this Scientific Journal Video about Single Read and Paired End mRNA-Seq Illumina Libraries from 10 Nanograms Total RNA at JoVE.com

Single Read and Paired End mRNA-Seq Illumina Libraries from 10 Nanograms Total RNA

Nous décrivons ici une méthode pour la préparation des deux simples de lecture et jumelé fin Illumina ARNm-Seq bibliothèques de séquençage de l&#39;analyse d&#39;expression génique basée sur l&#39;ARN T7 linéaires d&#39;amplification. Ce protocole ne nécessite que 10 nanogrammes d&#39;ARN total de départ et génère des bibliothèques très cohérente représentant transcriptions ensemble.

Simple Lire et jumelés bibliothèques Fin Illumina ARNm-Seq de 10 nanogrammes d&#39;ARN total

Whole transcriptome sequencing by mRNA-Seq is now used extensively to perform global gene expression, mutation, allele-specific expression and other ...

single-read-paired-end-mrna-seq-illumina-libraries-from-10-nanograms

Research

JoVE Journal

Biology

39.1K vues.  Morgridge Institute for Research. Nous décrivons ici une méthode pour la préparation des deux simples de lecture et jumelé fin Illumina ARNm-Seq bibliothèques de séquençage de l'analyse d'expression génique basée sur l'ARN T7 linéaires d'amplification. Ce protocole ne nécessite que 10 nanogrammes d'ARN total de départ et génère des bibliothèques très cohérente représentant transcriptions ensemble.

Vidéo: Single Read and Paired End mRNA-Seq Illumina Libraries from 10 Nanograms Total RNA

Large-Scale Screens of Metagenomic Libraries

Metagenomic libraries archive large fragments of contiguous genomic sequences from microorganisms without requiring prior cultivation. Generating a streamlined procedure for creating and screening metagenomic libraries is therefore useful for efficient high-throughput investigations into the genetic and metabolic properties of uncultured microbial assemblages. Here, key protocols are presented on video, which we propose is the most useful format for accurately describing a long process that alternately depends on robotic instrumentation and (human) manual interventions. First, we employed robotics to spot library clones onto high-density macroarray membranes, each of which can contain duplicate colonies from twenty-four 384-well library plates. Automation is essential for this procedure not only for accuracy and speed, but also due to the miniaturization of scale required to fit the large number of library clones into highly dense spatial arrangements. Once generated, we next demonstrated how the macroarray membranes can be screened for genes of interest using modified versions of standard protocols for probe labeling, membrane hybridization, and signal detection. We complemented the visual demonstration of these procedures with detailed written descriptions of the steps involved and the materials required, all of which are available online alongside the video.

Grands écrans des banques métagénomiques

Metagenomic libraries archive large fragments of contiguous genomic sequences from microorganisms without requiring prior cultivation.  Generating a ...

Recherche

Biologie

RNA Extraction from Neuroprecursor Cells Using the Bio-Rad Total RNA Kit

Extraction d&#39;ARN à partir de cellules Neuroprecursor Utiliser le Bio-Rad ARN total Kit

Obtaining High Quality RNA from Single Cell Populations in Human Postmortem Brain Tissue

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression profiles of pyramidal neurons in layer III. It is well known that the cerebral cortex is an exceptionally heterogeneous structure comprising diverse regions, layers and cell types, each of which is characterized by distinct cellular and molecular compositions and therefore differential gene expression profiles. To circumvent the confounding effects of tissue heterogeneity, we used laser-capture microdissection (LCM) in order to isolate our specific cell-type i.e pyramidal neurons.
Approximately 500 pyramidal neurons stained with the Histogene staining solution were captured using the Arcturus XT LCM system. RNA was then isolated from captured cells and underwent two rounds of T7-based linear amplification using Arcturus/Molecular Devices kits. The Experion LabChip (Bio-Rad) gel and electropherogram indicated good quality a(m)RNA, with a transcript length extending past 600nt required for microarrays. The amount of mRNA obtained averaged 51&mu;g, with acceptable mean sample purity as indicated by the A260/280 ratio, of 2.5. Gene expression was profiled using the Human X3P GeneChip probe array from Affymetrix.

We describe a process using laser-capture microdissection to isolate and extract RNA from a homogeneous cell population, pyramidal neurons, in layer III of the superior temporal gyrus in postmortem human brains. We subsequently linearly amplify (T7-based) mRNA, and hybridize the sample to the Affymetrix human X3P microarray.

Obtention d&#39;ARN de haute qualité provenant des populations cellule unique de tissus post-mortem du cerveau de l&#39;homme

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression ...

A High Throughput Screen for Biomining Cellulase Activity from Metagenomic Libraries

Cellulose, the most abundant source of organic carbon on the planet, has wide-ranging industrial applications with increasing emphasis on biofuel production 1. Chemical methods to modify or degrade cellulose typically require strong acids and high temperatures. As such, enzymatic methods have become prominent in the bioconversion process. While the identification of active cellulases from bacterial and fungal isolates has been somewhat effective, the vast majority of microbes in nature resist laboratory cultivation. Environmental genomic, also known as metagenomic, screening approaches have great promise in bridging the cultivation gap in the search for novel bioconversion enzymes. Metagenomic screening approaches have successfully recovered novel cellulases from environments as varied as soils 2, buffalo rumen 3 and the termite hind-gut 4 using carboxymethylcellulose (CMC) agar plates stained with congo red dye (based on the method of Teather and Wood 5). However, the CMC method is limited in throughput, is not quantitative and manifests a low signal to noise ratio 6. Other methods have been reported 7,8 but each use an agar plate-based assay, which is undesirable for high-throughput screening of large insert genomic libraries. Here we present a solution-based screen for cellulase activity using a chromogenic dinitrophenol (DNP)-cellobioside substrate 9. Our library was cloned into the pCC1 copy control fosmid to increase assay sensitivity through copy number induction 10. The method uses one-pot chemistry in 384-well microplates with the final readout provided as an absorbance measurement. This readout is quantitative, sensitive and automated with a throughput of up to 100X 384-well plates per day using a liquid handler and plate reader with attached stacking system.

This protocol describes a high throughput screen for cellulolytic activity from a metagenomic library expressed in Escherichia coli. The screen is solution based and highly automated, and uses one-pot chemistry in 384 well microplates with the final readout as an absorbance measurement.

Un écran à haut débit pour la bioprospection minière activité cellulase à partir des bibliothèques métagénomique

Cellulose, the most abundant source of organic carbon on the planet, has wide-ranging industrial applications with increasing emphasis on biofuel ...

In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection

In vitro transcription is the synthesis of RNA transcripts by RNA polymerase from a linear DNA template containing the corresponding promoter sequence (T7, T3, SP6) and the gene to be transcribed (Figure 1A). A typical transcription reaction consists of the template DNA, RNA polymerase, ribonucleotide triphosphates, RNase inhibitor and buffer containing Mg2+ ions.
Large amounts of high quality RNA are often required for a variety of applications. Use of in vitro transcription has been reported for RNA structure and function studies such as splicing1, RNAi experiments in mammalian cells2, antisense RNA amplification by the "Eberwine method"3, microarray analysis4 and for RNA vaccine studies5. The technique can also be used for producing radiolabeled and dye labeled probes6. Warren, et al. recently reported reprogramming of human cells by transfection with in vitro transcribed capped RNA7. The T7 High Yield RNA Synthesis Kit from New England Biolabs has been designed to synthesize up to 180 &mu;g RNA per 20 &mu;l reaction. RNA of length up to 10kb has been successfully transcribed using this kit. Linearized plasmid DNA, PCR products and synthetic DNA oligonucleotides can be used as templates for transcription as long as they have the T7 promoter sequence upstream of the gene to be transcribed.
Addition of a 5' end cap structure to the RNA is an important process in eukaryotes. It is essential for RNA stability8, efficient translation9, nuclear transport10 and splicing11. The process involves addition of a 7-methylguanosine cap at the 5' triphosphate end of the RNA. RNA capping can be carried out post-transcriptionally using capping enzymes or co-transcriptionally using cap analogs. In the enzymatic method, the mRNA is capped using the Vaccinia virus capping enzyme12,13. The enzyme adds on a 7-methylguanosine cap at the 5' end of the RNA using GTP and S-adenosyl methionine as donors (cap 0 structure). Both methods yield functionally active capped RNA suitable for transfection or other applications14 such as generating viral genomic RNA for reverse-genetic systems15 and crystallographic studies of cap binding proteins such as eIF4E16.
In the method described below, the T7 High Yield RNA Synthesis Kit from NEB is used to synthesize capped and uncapped RNA transcripts of Gaussia luciferase (GLuc) and Cypridina luciferase (CLuc). A portion of the uncapped GLuc RNA is capped using the Vaccinia Capping System (NEB). A linearized plasmid containing the GLuc or CLuc gene and T7 promoter is used as the template DNA. The transcribed RNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity. Capped CLuc RNA is used as the internal control to normalize GLuc expression.

In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection

This method describes high yield in vitro synthesis of both capped and uncapped mRNA from a linearized plasmid containing the Gaussia luciferase (GLuc) gene. The RNA is purified and a fraction of the uncapped RNA is enzymatically capped using the Vaccinia virus capping enzyme. In the final step, the mRNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity.

Transcription in vitro et plafonnement de l&#39;ARNm de luciférase Gaussia Suivie par la transfection de cellules HeLa

In vitro transcription is the synthesis of RNA transcripts by RNA polymerase from a linear DNA template containing the corresponding promoter sequence ...

Chromatin Interaction Analysis with Paired-End Tag Sequencing (ChIA-PET) for Mapping Chromatin Interactions and Understanding Transcription Regulation

Genomes are organized into three-dimensional structures, adopting higher-order conformations inside the micron-sized nuclear spaces 7, 2, 12. Such architectures are not random and involve interactions between gene promoters and regulatory elements 13. The binding of transcription factors to specific regulatory sequences brings about a network of transcription regulation and coordination 1, 14. 
Chromatin Interaction Analysis by Paired-End Tag Sequencing (ChIA-PET) was developed to identify these higher-order chromatin structures 5,6. Cells are fixed and interacting loci are captured by covalent DNA-protein cross-links. To minimize non-specific noise and reduce complexity, as well as to increase the specificity of the chromatin interaction analysis, chromatin immunoprecipitation (ChIP) is used against specific protein factors to enrich chromatin fragments of interest before proximity ligation. Ligation involving half-linkers subsequently forms covalent links between pairs of DNA fragments tethered together within individual chromatin complexes. The flanking MmeI restriction enzyme sites in the half-linkers allow extraction of paired end tag-linker-tag constructs (PETs) upon MmeI digestion. As the half-linkers are biotinylated, these PET constructs are purified using streptavidin-magnetic beads. The purified PETs are ligated with next-generation sequencing adaptors and a catalog of interacting fragments is generated via next-generation sequencers such as the Illumina Genome Analyzer. Mapping and bioinformatics analysis is then performed to identify ChIP-enriched binding sites and ChIP-enriched chromatin interactions 8. 
We have produced a video to demonstrate critical aspects of the ChIA-PET protocol, especially the preparation of ChIP as the quality of ChIP plays a major role in the outcome of a ChIA-PET library. As the protocols are very long, only the critical steps are shown in the video.

Chromatin Interaction Analysis with Paired-End Tag Sequencing ChIA-PET for Mapping Chromatin Interactions and Understanding Transcription Regulation

Chromatin Interaction Analysis by Paired-End Tag Sequencing (ChIA-PET) is a method for de novo detection of chromatin interactions, for better understanding of transcriptional control.

Analyse de l&#39;interaction avec la chromatine Tag appariés Fin de séquençage (Chia-PET) pour la cartographie des interactions Chromatine et transcription Comprendre le règlement

Genomes are organized into three-dimensional structures, adopting higher-order conformations inside the micron-sized nuclear spaces 7, 2, 12. Such ...

TChIP-Seq: Cell-Type-Specific Epigenome Profiling

Epigenetic regulation plays central roles in gene expression. Since histone modification was discovered in the 1960s, its physiological and pathological functions have been extensively studied. Indeed, the advent of next-generation deep sequencing and chromatin immunoprecipitation (ChIP) via specific histone modification antibodies has revolutionized our view of epigenetic regulation across the genome. Conversely, tissues typically consist of diverse cell types, and their complex mixture poses analytic challenges to investigating the epigenome in a particular cell type. To address the cell type-specific chromatin state in a genome-wide manner, we recently developed tandem chromatin immunoprecipitation sequencing (tChIP-Seq), which is based on the selective purification of chromatin by tagged core histone proteins from cell types of interest, followed by ChIP-Seq. The goal of this protocol is the introduction of best practices of tChIP-Seq. This technique provides a versatile tool for tissue-specific epigenome investigation in diverse histone modifications and model organisms.

We describe a step-by-step protocol for tandem chromatin immunoprecipitation sequencing (tChIP-Seq) that enables the analysis of cell-type-specific genome-wide histone modification.

TChIP-Seq : Type-spécifiques des cellules épigénome profilage

Epigenetic regulation plays central roles in gene expression. Since histone modification was discovered in the 1960s, its physiological and pathological ...

Nuclei Isolation from Adult Mouse Kidney for Single-Nucleus RNA-Sequencing

The kidneys regulate diverse biological processes such as water, electrolyte, and acid-base homeostasis. Physiological functions of the kidney are executed by multiple cell types arranged in a complex architecture across the corticomedullary axis of the organ. Recent advances in single-cell transcriptomics have accelerated the understanding of cell type-specific gene expression in renal physiology and disease. However, enzyme-based tissue dissociation protocols, which are frequently utilized for single-cell RNA-sequencing (scRNA-seq), require mostly fresh (non-archived) tissue, introduce transcriptional stress responses, and favor the selection of abundant cell types of the kidney cortex resulting in an underrepresentation of cells of the medulla.
Here, we present a protocol that avoids these problems. The protocol is based on nuclei isolation at 4 &#176;C from frozen kidney tissue. Nuclei are isolated from a central piece of the mouse kidney comprised of the cortex, outer medulla, and inner medulla. This reduces the overrepresentation of cortical cells typical for whole-kidney samples for the benefit of medullary cells such that data will represent the entire corticomedullary axis at sufficient abundance. The protocol is simple, rapid, and adaptable and provides a step towards the standardization of single-nuclei transcriptomics in kidney research.

Here, we present a protocol to isolate high-quality nuclei from frozen mouse kidneys that improve the representation of medullary kidney cell types and avoids the gene expression artifacts from enzymatic tissue dissociation.

Isolement de noyaux à partir de reins de souris adultes pour le séquençage de l’ARN mononucléaire

The kidneys regulate diverse biological processes such as water, electrolyte, and acid-base homeostasis. Physiological functions of the kidney are ...

Isolement et profilage de noyaux uniques à partir de tissus de mammifères congelés

A Simple, Quick, and Partially Automated Protocol for the Isolation of Single Nuclei from Frozen Mammalian Tissues for Single Nucleus Sequencing

Single-cell and single-nucleus RNA sequencing have become common laboratory applications due to the wealth of transcriptomic information that they provide. Single nucleus RNA sequencing, particularly, is useful for investigating gene expression in difficult-to-dissociate tissues. Furthermore, this approach is also compatible with frozen (archival) material. Here, we describe a protocol to isolate high-quality single nuclei from frozen mammalian tissues for downstream single nucleus RNA sequencing in a partially-automated manner using commercially available instruments and reagents. Specifically, a robotic dissociator is used to automate and standardize tissue homogenization, followed by an optimized chemical gradient to filter the nuclei. Lastly, we accurately and automatically count the nuclei using an automated fluorescent cell counter. The performance of this protocol is demonstrated on mouse brain, rat kidney, and cynomolgus liver and spleen tissue. This protocol is straightforward, rapid, and readily adaptable to various mammalian tissues without requiring extensive optimization and provides good quality nuclei for downstream single nuclei RNA sequencing.

Pleins feux sur l’auteur : Améliorer la découverte de médicaments - Développement de protocoles automatisés et standardisés pour l’extraction de noyaux à partir de tissus congelés 

The study describes a simple, quick, and partially automated protocol to isolate high-quality nuclei from frozen mammalian tissues for downstream single nuclei RNA sequencing.

Un protocole simple, rapide et partiellement automatisé pour l’isolement de noyaux uniques à partir de tissus de mammifères congelés pour le séquençage d’un seul noyau