Name: technical demonstration of whole genome array comparative genomic hybridization
Uploaded: 2008-08-05T18:06:00.000+00:00
Duration: 16 min 37 s
Description: Watch this Scientific Journal Video about Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization at JoVE.com

Nous tenons à remercier les membres de l&#39;équipe de Wan Lam Lab tableau BAC particulier Miwa Suzuki et Bryan Chi pour la préparation de cet article. Ce travail a été soutenu par des fonds des Instituts canadiens de recherche en santé, Génome Canada / Génome Colombie-Britannique, et le NIH / NIDCR octroi RO1 DE15965-01.

SONDE D&#39;ETIQUETAGE Remarque: limiter l&#39;exposition des Colorants Cye à la lumière, à tout moment (cela peut être réalisé en travaillant dans une zone obscurcie ou en protégeant les tubes avec une couverture comme le papier d&#39;aluminium) <ol><li> Combiner: (Configuration 1 tube de réaction pour référence et 1 tube de réaction pour l&#39;échantillon) <ul><li> L&#39;ADN (25-400 ng) </li><li> 5 pi de tampon 5X amorces aléatoires (concentration finale: 5X Promega Klenow tampon et 7 pg / uL octamères aléatoire) </li><li> Diluer à 17,0 volume total d&#39;eau distillée uL H 2 O </li></ul></li><li> Faire bouillir pendant 10 minutes à 100 ° C. Transfert immédiatement à la glace pendant 1 minute. </li><li> Ajouter 4 pi de mélange dNTP 10X (2 mM de dATP, dGTP, dTTP, dCTP 1,2 mm). </li><li> Ajouter CyeDyes: <ul><li> Ajouter 2 uL (2 nmoles) de Cy-3 dCTP marqués à l&#39;ADN échantillon </li><li> Ajouter 2 uL (2 nmoles) de Cy-5 étiqueté dCTP à l&#39;ADN de référence (par exemple, l&#39;ADN génomique humain Novagen) </li></ul></li><li> Ajouter 2,5 pi de Klenow (9 U / uL, Promega) et mélanger. </li><li> Incuber à 37 ° C pendant la nuit * (~ 18 heures). * Le temps d&#39;hybridation pendant la nuit peut être ajustée entre 14 à 24 heures sans affecter négativement le processus d&#39;étiquetage pour s&#39;adapter à un horaire de laboratoire. </li></ol> Purification de l&#39;échantillon (Sonde combinée de nettoyage et de préparation à l&#39;hybridation) <ol><li> L&#39;utilisation d&#39;un Microcon YM-30 colonne: <ul><li> Ajouter 100 Cot-1 uL d&#39;ADN (1μg/μL) à la colonne. Ne pas toucher la membrane avec la pointe de pipette. </li><li> Piscine les réactions (référence et échantillon) et ajouter à la colonne. </li><li> Colonne de la Place dans le tube fourni et centrifuger à 13000 g pendant 10 minutes. </li><li> Ajouter 200 ul distillée H 2 0 à la membrane et répéter spin pour se laver. </li><li> Jeter le tube et ajouter 45 uL solution d&#39;hybridation: (Roche DIG Easy) </li></ul> Optionnel: Ajouter 5uL ADN cisaillé de sperme de hareng (unité 10μg/μL, Promega) <ul><li> Inverser Microcon, placer dans un nouveau tube étiqueté, et tournent à 3000 g pendant 3 minutes. </li></ul></li></ol> CALCUL DU INCORPORATIONS <ol><li> Retirez 1,5 uL et l&#39;incorporation fluorophore mesurer à l&#39;aide Spectrophotomètre NanoDrop. Utilisation de votre tampon d&#39;hybridation comme une vierge (DIG Easy) suivez les instructions à l&#39;écran. (Vous pouvez récupérer l&#39;échantillon du piédestal, si nécessaire, après la mesure.) (Remarque:. Incorporations inférieur à 3,0 pmol / uL dans deux canaux ont montré des résultats variables) </li><li> Dénaturer à 85 ° C pendant 10 minutes. </li><li> Placez la sonde à 45 ° C pendant 30 minutes à 1 heure (Cot-1 permet l&#39;ADN recuit.) </li></ol> HYBRIDATION ARRAY <ol><li> Placer 44 uL solution de sonde sur la lamelle (22 mm x 60 mm) (Fisher Scientific). Si possible, placer la lamelle sur une lame chaude ou de bloquer la chaleur pré-chauffé à 45 ° C pour maintenir la température. </li><li> Aligner glisser sur la lamelle et solution de sonde, la baisse d&#39;un bord de la diapositive permettant le contact avec la solution d&#39;hybridation. Continuer d&#39;abaisser jusqu&#39;à ce que la lamelle est attaché à la lame avec la tension de surface. Inverser la diapositive. </li><li> Placer la lame dans la cassette d&#39;hybridation (Telechem), pré-chauffé à 45 ° C, et ajouter 10 uL d&#39;eau dans la rainure inférieure (pour contrôler l&#39;humidité lors de l&#39;hybridation). </li><li> Cassette Seal et incuber pendant 36 - 40 heures à 45 ° C. </li></ol> LAVAGE ARRAY Note: Toutes les solutions de lavage sont à pH 7,0 Retrait de la glissière de la cassette hybridation est critique. DIG Facile cristallise rapidement à température ambiante. La lame doit être immédiatement immergé et la lamelle enlevée dans la solution de lavage. <ol><li> Ajouter environ 60 ml d&#39;0.1XSSC, SDS 0,1% (pH 7,0, 45 ° C) la solution de lavage à une jarre de Coplin avant l&#39;ouverture de la chambre d&#39;hybridation. </li><li> Ouvrez la chambre, ajoutez diapositive à la solution de lavage et enlever la lamelle (il faut glisser). </li><li> Laver la lame 3 fois dans 0.1XSSC + 0,1% SDS à 45 ° C pendant 1 minute chacun avec agitation. </li><li> Rincer la lame 3 fois dans 0.1XSSC frais *. Il devrait y avoir aucune bulle résiduelle de la SDD se laver visibles. * Les diapositives peuvent rester dans la solution de lavage final jusqu&#39;au moment de centrifugeuses et de numérisation (~ 15 minutes). </li><li> Centrifuger la lame dans un des tubes de 50 ml Falcon à 700 g pendant 3 minutes. </li><li> Immédiatement numériser les diapositives (intensités du signal diminue avec le temps.) </li></ol>

<ol>
	<li>Lockwood, W. W., Chari, R., Chi, B., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+array+comparative+genomic+hybridization+technologies+and+their+applications+in+human+genetics.">Recent advances in array comparative genomic hybridization technologies and their applications in human genetics.</a> European Journal of Human Genetics. 14, 139-1x`48 (2006).</li><li>Ishkanian, A. S., Malloff, C. A., Watson, S. K., deLeeuw, R. J., Chi, B., Coe, B. P., Snijders, A., Albertson, D. G., Pinkel, D., Marra, M. A., Ling, V., MacAulay, C., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+tiling+resolution+DNA+microarray+with+complete+coverage+of+the+human+genome.">A tiling resolution DNA microarray with complete coverage of the human genome.</a> Nature Genetics. 36, 299-303 (2004).</li><li>Watson, S. K., DeLeeuw, R. J., Ishkanian, A. S., Malloff, C. A., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+for+high+throughput+validation+of+amplified+fragment+pools+of+BAC+DNA+for+constructing+high+resolution+CGH+arrays.">Methods for high throughput validation of amplified fragment pools of BAC DNA for constructing high resolution CGH arrays.</a> BMC Genomics. 5, 6 (2004).</li><li>Watson, S. K., DeLeeuw, R. J., Horsman, D. E., Squire, J. A., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytogenetically+balanced+translocations+are+associated+with+focal+copy+number+alterations.">Cytogenetically balanced translocations are associated with focal copy number alterations.</a> Human Genetics. 120, 795-805 (2007).</li><li>Chi, B., DeLeeuw, R. J., Coe, B. P., MacAulay, C., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SeeGH+--+a+software+tool+for+visualization+of+whole+genome+array+comparative+genomic+hybridization+data.">SeeGH -- a software tool for visualization of whole genome array comparative genomic hybridization data.</a> BMC Bioinformatics. 5, 13 (2004).</li><li>Chi, B., DeLeeuw, R. J., Coe, B. P., Ng, R. T., MacAulay, C., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MD-SeeGH:+a+platform+for+integrative+analysis+of+multi-dimensional+genomic+data.">MD-SeeGH: a platform for integrative analysis of multi-dimensional genomic data.</a> BMC Bioinformatics. 9, 243 (2008).</li><li>Coe, B. P., Ylstra, B., Carvalho, B., Meijer, G. A., Macaulay, C., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resolving+the+resolution+of+array+CGH.">Resolving the resolution of array CGH.</a> Genomics. 89, 647-653 (2007).</li><li>Garnis, C., Coe, B. P., Lam, S. L., MacAulay, C., Lam, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+array+CGH+increases+heterogeneity+tolerance+in+the+analysis+of+clinical+samples.">High-resolution array CGH increases heterogeneity tolerance in the analysis of clinical samples.</a> Genomics. 85, 790-793 (2005).</li></ol>

La mauvaise qualité de l&#39;ADN ne fournira pas un profil d&#39;hybridation bien. Il est essentiel de s&#39;assurer que l&#39;échantillon d&#39;ADN de référence et sont exempts de contaminants tels que le phénol, l&#39;ARN, le sel, etc qui peuvent interférer avec l&#39;étape de marquage Premier aléatoire avant de commencer une expérience d&#39;hybridation. Par exemple, la remise en suspension de l&#39;ADN dans Tris - EDTA (TE) au lieu de l&#39;eau n&#39;est pas recommandée car la concentration en sel élevée peut inhiber la réa...

<table><tbody><tr><td>5X Klenow Buffer</td><td>Reagent</td><td>Promega Corp.</td><td></td><td></td></tr><tr><td>Random Octamers </td><td>Reagent</td><td>Alpha DNA</td><td></td><td></td></tr><tr><td>10X dNTP mix</td><td>Reagent</td><td>Promega Corp.</td><td></td><td>2mM dATP, dGTP, dTTP, 1.2mM dCTP</td></tr><tr><td>Cy-3 labeled dCTP</td><td>Reagent</td><td>GE Healthcare</td><td></td><td></td></tr><tr><td>Cy-5 labeled dCTP</td><td>Reagent</td><td>GE Healthcare</td><td></td><td></td></tr><tr><td>Human Genomic DNA Reference</td><td>Reagent</td><td>Novagen, EMD Millipore</td><td></td><td>Example of a possible reference</td></tr><tr><td>Klenow</td><td>Reagent</td><td>Promega Corp.</td><td></td><td></td></tr><tr><td>YM-30 Column</td><td>Reagent</td><td>EMD Millipore</td><td></td><td></td></tr><tr><td>Cot-1 DNA</td><td>Reagent</td><td>Invitrogen</td><td></td><td></td></tr><tr><td>DIG Easy</td><td>Reagent</td><td>Roche Group</td><td></td><td></td></tr><tr><td>Sheared Herring Sperm DNA</td><td>Reagent</td><td>Promega Corp.</td><td></td><td></td></tr><tr><td>Coverslip</td><td>Reagent</td><td>Fisher Scientific</td><td></td><td>22mm x 60mm</td></tr><tr><td>Hybridization Cassette</td><td>Tool</td><td>Telechem</td><td></td><td></td></tr></tbody></table>

technical demonstration of whole genome array comparative genomic hybridization

Hybridation génomique comparative (CGH array) est une méthode pour détecter les gains et pertes de segments d&#39;ADN ou le dosage des gènes dans le génome 1. Les avancées récentes dans cette technologie ont permis de comparaison haute résolution des génomes entiers pour l&#39;identification d&#39;altérations génétiques dans le cancer et autres maladies génétiques 2. Le Sous-Megabase Résolution Carrelage-set tableau (ou SMRT) tableau est composé d&#39;un ensemble d&#39;environ trente mille bactéries qui se chevauchent chromosomes artificiels (BAC) des clones qui couvrent le génome humain en ~ 100 paires kilobases (kb) des segments 2. Ces cibles d&#39;alcoolémie sont individuellement synthétisés et repéré en double sur une lame de verre simple 2-4. CGH array est basé sur le principe de l&#39;hybridation compétitive. Des échantillons et l&#39;ADN de référence sont étiquetés avec différentiel Cyanine-3 et colorants de cyanine-5 fluorescentes, et co-hybride à la matrice. Après une période d&#39;incubation de l&#39;échantillon non liés sont lavés de la diapositive et le tableau est imagé. Un logiciel librement disponible personnalisé appelé SeeGH (www.flintbox.ca) est utilisé pour traiter l&#39;important volume de données recueillies - une expérience unique génère 53 892 points de données. SeeGH visualise le ratio d&#39;intensité de signal entre le log2 2 échantillons à chaque cible d&#39;alcoolémie qui est aligné verticalement avec la position chromosomique 5,6. Le tableau SMRT peut détecter des altérations aussi petite que 50 kb 7. Le tableau SMRT peut détecter une variété d&#39;événements réarrangement d&#39;ADN y compris les gains d&#39;ADN, des pertes, des amplifications et délétions homozygotes. Un avantage unique de la matrice de SMRT est que l&#39;on peut utiliser l&#39;ADN isolé à partir d&#39;échantillons de paraffine fixés au formol embarqués. Lorsqu&#39;il est combiné avec les exigences d&#39;entrée faible de l&#39;ADN non amplifié (25-100 ng) ce qui permet le profilage des échantillons précieux tels que ceux produits par microdissection 7,8. Ceci est attribué à la grande taille de chacune des cibles hybridation BAC, qui permet la liaison de suffisamment d&#39;échantillons étiquetés pour produire des signaux pour la détection. Un autre avantage de cette plateforme est la tolérance de l&#39;hétérogénéité des tissus, en diminuant le besoin de microdissection tissulaire fastidieuse 8. Ce protocole est un tutoriel vidéo étape par étape, de marquage de l&#39;ADN d&#39;entrée grâce à l&#39;acquisition du signal pour le tableau du génome de carrelage SMRT toute voie.

Watch this Scientific Journal Video about Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization at JoVE.com

Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization

Cette vidéo est une démonstration technique du protocole d&#39;hybridation pour l&#39;ensemble du génome de carrelage CGH array chemin, qui scanne l&#39;ensemble du génome humain en utilisant seulement 25 à 100 ng d&#39;ADN qui peuvent être isolées à partir de diverses sources, y compris les archives du matériel fixé au formol.

Démonstration technique de l&#39;hybridation tableau Whole Genome génomique comparative

Array comparative genomic hybridization (array CGH) is a method for detecting gains and losses of DNA segments or gene dosage in the genome 1.  Recent ...

technical-demonstration-whole-genome-array-comparative-genomic

Research

JoVE Journal

Biology

12.7K vues.  BC Cancer Research Centre. *The slides can remain in the 

Vidéo: Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization

The Terroir Concept Interpreted through Grape Berry Metabolomics and Transcriptomics

Terroir refers to the combination of environmental factors that affect the characteristics of crops such as grapevine (Vitis vinifera) according to particular habitats and management practices. This article shows how certain terroir signatures can be detected in the berry metabolome and transcriptome of the grapevine cultivar Corvina using multivariate statistical analysis. The method first requires an appropriate sampling plan. In this case study, a specific clone of the Corvina cultivar was selected to minimize genetic differences, and samples were collected from seven vineyards representing three different macro-zones during three different growing seasons. An untargeted LC-MS metabolomics approach is recommended due to its high sensitivity, accompanied by efficient data processing using MZmine software and a metabolite identification strategy based on fragmentation tree analysis. Comprehensive transcriptome analysis can be achieved using microarrays containing probes covering ~99% of all predicted grapevine genes, allowing the simultaneous analysis of all differentially expressed genes in the context of different terroirs. Finally, multivariate data analysis based on projection methods can be used to overcome the strong vintage-specific effect, allowing the metabolomics and transcriptomics data to be integrated and analyzed in detail to identify informative correlations.

This article describes the application of untargeted metabolomics, transcriptomics and multivariate statistical analysis to grape berry transcripts and metabolites in order to gain insight into the terroir concept, i.e., the impact of the environment on berry quality traits.

Le concept Terroir Interprété par Grape Berry métabolomique et transcriptomique

Terroir refers to the combination of environmental factors that affect the characteristics of crops such as grapevine (Vitis vinifera) according to ...

Recherche

Génétique

An Array-based Comparative Genomic Hybridization Platform for Efficient Detection of Copy Number Variations in Fast Neutron-induced Medicago truncatula Mutants

Mutants are invaluable genetic resources for gene function studies. To generate mutant collections, three types of mutagens can be utilized, including biological such as T-DNA or transposon, chemical such as ethyl methanesulfonate (EMS), or physical such as ionization radiation. The type of mutation observed varies depending on the mutagen used. For ionization radiation induced mutants, mutations include deletion, duplication, or rearrangement. While T-DNA or transposon-based mutagenesis is limited to species that are susceptible to transformation, chemical or physical mutagenesis can be applied to a broad range of species. However, the characterization of mutations derived from chemical or physical mutagenesis traditionally relies on a map-based cloning approach, which is labor intensive and time consuming. Here, we show that a high-density genome array-based comparative genomic hybridization (aCGH) platform can be applied to efficiently detect and characterize copy number variations (CNVs) in mutants derived from fast neutron bombardment (FNB) mutagenesis in Medicago truncatula, a legume species. Whole genome sequence analysis shows that there are more than 50,000 genes or gene models in M. truncatula. At present, FNB-induced mutants in M. truncatula are derived from more than 150,000 M1 lines, representing invaluable genetic resources for functional studies of genes in the genome. The aCGH platform described here is an efficient tool for characterizing FNB-induced mutants in M. truncatula.

An Array-based Comparative Genomic Hybridization Platform for Efficient Detection of Copy Number Variations in Fast Neutron-induced Medicago truncatula Mutants

This protocol provides experimental steps and information about reagents, equipment, and analysis tools for researchers who are interested in carrying out whole genome array-based comparative genomic hybridization (CGH) analysis of copy number variations in plants.

Une tableau comparatif génomique hybridation plate-forme pour détection efficace de copie nombre Variations chez les Mutants induite par neutrons rapides Medicago truncatula

Mutants are invaluable genetic resources for gene function studies. To generate mutant collections, three types of mutagens can be utilized, including ...

High-Density DNA and RNA microarrays - Photolithographic Synthesis, Hybridization and Preparation of Large Nucleic Acid Libraries

Photolithography is a powerful technique for the synthesis of DNA oligonucleotides on glass slides, as it combines the efficiency of phosphoramidite coupling reactions with the precision and density of UV light reflected from micrometer-sized mirrors. Photolithography yields microarrays that can accommodate from hundreds of thousands up to several million different DNA sequences, 100-nt or longer, in only a few hours. With this very large sequence space, microarrays are ideal platforms for exploring the mechanisms of nucleic acid&#183;ligand interactions, which are particularly relevant in the case of RNA. We recently reported on the preparation of a new set of RNA phosphoramidites compatible with in situ photolithography and which were subsequently used to grow RNA oligonucleotides, homopolymers as well as mixed-base sequences. Here, we illustrate in detail the process of RNA microarray fabrication, from the experimental design, to instrumental setup, array synthesis, deprotection and final hybridization assay using a template 25mer sequence containing all four bases as an example. In parallel, we go beyond hybridization-based experiments and exploit microarray photolithography as an inexpensive gateway to complex nucleic acid libraries. To do so, high-density DNA microarrays are fabricated on a base-sensitive monomer that allows the DNA to be conveniently cleaved and retrieved after synthesis and deprotection. The fabrication protocol is optimized so as to limit the number of synthetic errors and to that effect, a layer of &#946;-carotene solution is introduced to absorb UV photons that may otherwise reflect back onto the synthesis substrates. We describe in a step-by-step manner the complete process of library preparation, from design to cleavage and quantification.

In this article, we present and discuss new developments in the synthesis and applications of nucleic acid microarrays fabricated in situ. Specifically, we show how the protocols for DNA synthesis can be extended to RNA and how microarrays can be used to create retrievable nucleic acid libraries.

Microréseaux d'ADN et d'ARN à haute densité - Synthèse photolithographique, hybridation et préparation des grandes bibliothèques d'acide nucléique

Photolithography is a powerful technique for the synthesis of DNA oligonucleotides on glass slides, as it combines the efficiency of phosphoramidite ...

Global Gene Expression Analysis Using a Zebrafish Oligonucleotide Microarray Platform

Gene microarray technology permits quantitative measurement and gene expression profiling of transcript levels on a genome-wide basis. Gene microarray technology is used in numerous biological disciplines in a variety of applications including global gene expression analysis in relation to developmental stage, to a disease state, and in toxic responses. Herein, we include a demonstration of global gene expression analysis using a comprehensive zebrafish-specific oligonucleotide microarray platform. The zebrafish expression microarray platform contains 385,000 probes, 60 base pairs in length, interrogating 37,157 targets with up to 12 probes per target. For this platform, all cDNA and genomic information available for the zebrafish was collected from various genomic databases including Ensembl (http://www.ensembl.org), VEGA (http://vega.sanger.ac.uk), UCSC (http://genome.ucsc.edu), and ZFIN (http://www.zfin.org). As a result this expression array provides complete coverage of the current zebrafish transcriptome. The zebrafish expression microarray was printed by Roche NimbleGen (Madison, WI). This technical demonstration includes the fluorescent labeling of a cDNA product, hybridization of the labeled cDNA product to the microarray platform, and array scanning for signal acquisition using the one color analysis strategy.  

Gene microarrays are powerful tools in gene expression profiling at a genome-wide level. This technology has application in a variety of biological disciplines including developmental biology and toxicology. In this video, we detail a protocol for global gene expression analysis using a comprehensive oligonucleotide microarray platform for the zebrafish.

Mondial Analyse expression génique utilisant une plateforme biopuces oligonucléotidiques Zebrafish

Gene microarray technology permits quantitative measurement and gene expression profiling of transcript levels on a genome-wide basis. Gene microarray ...

Biologie

A Rapid High-throughput Method for Mapping Ribonucleoproteins (RNPs) on Human pre-mRNA

Sequencing RNAs that co-immunoprecipitate (co-IP) with RNA binding proteins has increased our understanding of splicing by demonstrating that binding location often influences function of a splicing factor.  However, as with any sampling strategy the chance of identifying an RNA bound to a splicing factor is proportional to its cellular abundance.  We have developed a novel in vitro approach for surveying binding specificity on otherwise transient pre-mRNA. This approach utilizes a specifically designed oligonucleotide pool that tiles across introns, exons, splice junctions, or other pre-mRNA.  The pool is subjected to some kind of molecular selection. Here, we demonstrate the method by separating the oligonucleotide into a bound and unbound fraction and utilize a two color array strategy to record the enrichment of each oligonucleotide in the bound fraction. The array data generates high-resolution maps with the ability to identify sequence-specific and structural determinates of ribonucleoprotein (RNP) binding on pre-mRNA.  A unique advantage to this method is its ability to avoid the sampling bias towards mRNA associated with current IP and SELEX techniques, as the pool is specifically designed and synthesized from pre-mRNA sequence. The flexibility of the oligonucleotide pool is another advantage since the experimenter chooses which regions to study and tile across, tailoring the pool to their individual needs.  Using this technique, one can assay the effects of polymorphisms or mutations on binding on a large scale or clone the library into a functional splicing reporter and identify oligonucleotides that are enriched in the included fraction.  This novel in vitro high-resolution mapping scheme provides a unique way to study RNP interactions with transient pre-mRNA species, whose low abundance makes them difficult to study with current in vivo techniques.  



A Rapid High-throughput Method for Mapping Ribonucleoproteins RNPs on Human pre-mRNA

Due to the transient nature of pre-mRNA, it can be difficult to isolate and study in vivo. Here, we present a novel in vitro approach to investigate RNA-protein interactions using a synthetic oligo pool that tiles across selected regions of pre-mRNA.

Un rapide à haut débit Méthode de cartographie ribonucléoprotéines (RNP) sur l&#39;homme pré-ARNm

Sequencing RNAs that co-immunoprecipitate (co-IP) with RNA binding proteins has increased our understanding of splicing by demonstrating that binding ...

A Novel Strategy Combining Array-CGH, Whole-exome Sequencing and In Utero Electroporation in Rodents to Identify Causative Genes for Brain Malformations

Birth defects that involve the cerebral cortex &#8212; also known as malformations of cortical development (MCD) &#8212; are important causes of intellectual disability and account for 20-40% of drug-resistant epilepsy in childhood. High-resolution brain imaging has facilitated in vivo identification of a large group of MCD phenotypes. Despite the advances in brain imaging, genomic analysis and generation of animal models, a straightforward workflow to systematically prioritize candidate genes and to test functional effects of putative mutations is missing. To overcome this problem, an experimental strategy enabling the identification of novel causative genes for MCD was developed and validated. This strategy is based on identifying candidate genomic regions or genes via array-CGH or whole-exome sequencing and characterizing the effects of their inactivation or of overexpression of specific mutations in developing rodent brains via in utero electroporation. This approach led to the identification of the C6orf70 gene, encoding for a putative vesicular protein, to the pathogenesis of periventricular nodular heterotopia, a MCD caused by defective neuronal migration.

A Novel Strategy Combining Array-CGH, Whole-exome Sequencing and In Utero Electroporation in Rodents to Identify Causative Genes for Brain Malformations

Periventricular nodular heterotopia (PNH) is the most common form of malformation of cortical development (MCD) in adulthood but its genetic basis remains unknown in most sporadic cases. We have recently developed a strategy to identify novel candidate genes for MCDs and to directly confirm their causative role in vivo.

Une stratégie novatrice alliant CGH-Array, séquençage de l’exome-ensemble et électroporation de In Utero chez les rongeurs afin d’identifier les gènes pour les Malformations du cerveau

Birth defects that involve the cerebral cortex &#8212; also known as malformations of cortical development (MCD) &#8212; are important causes of ...

Neurosciences

DNA Microarrays: Sample Quality Control, Array Hybridization and Scanning

Microarray expression profiling of the nervous system provides a powerful approach to identifying gene activities in different stages of development, different physiological or pathological states, response to therapy, and, in general, any condition that is being experimentally tested1. Expression profiling of neural tissues requires isolation of high quality RNA, amplification of the isolated RNA and hybridization to DNA microarrays. In this article we describe protocols for reproducible microarray experiments from brain tumor tissue2. We will start by performing a quality control analysis of isolated RNA samples with Agilent's 2100 Bioanalyzer "lab-on-a-chip" technology. High quality RNA samples are critical for the success of any microarray experiment, and the 2100 Bioanalyzer provides a quick, quantitative measurement of the sample quality. RNA samples are then amplified and labeled by performing reverse transcription to obtain cDNA, followed by in vitro transcription in the presence of labeled nucleotides to produce labeled cRNA. By using a dual-color labeling kit, we will label our experimental sample with Cy3 and a reference sample with Cy5. Both samples will then be combined and hybridized to Agilent's 4x44 K arrays. Dual-color arrays offer the advantage of a direct comparison between two RNA samples, thereby increasing the accuracy of the measurements, in particular for small changes in expression levels, because the two RNA samples are hybridized competitively to a single microarray. The arrays will be scanned at the two corresponding wavelengths, and the ratio of Cy3 to Cy5 signal for each feature will be used as a direct measurement of the relative abundance of the corresponding mRNA. This analysis identifies genes that are differentially expressed in response to the experimental conditions being tested.

We demonstrate the use of DNA microarrays for expression profiling of the nervous system. We describe RNA quality control, sample labeling, and array hybridization and scanning.

Cellules souches: le contrôle qualité des échantillons, hybridation Array et balayage

Microarray expression profiling of the nervous system provides a powerful approach to identifying gene activities in different stages of development, ...

Competitive Genomic Screens of Barcoded Yeast Libraries

By virtue of advances in next generation sequencing technologies, we have access to new genome sequences almost daily. The tempo of these advances is accelerating, promising greater depth and breadth. In light of these extraordinary advances, the need for fast, parallel methods to define gene function becomes ever more important. Collections of genome-wide deletion mutants in yeasts and E. coli have served as workhorses for functional characterization of gene function, but this approach is not scalable, current gene-deletion approaches require each of the thousands of genes that comprise a genome to be deleted and verified. Only after this work is complete can we pursue high-throughput phenotyping. Over the past decade, our laboratory has refined a portfolio of competitive, miniaturized, high-throughput genome-wide assays that can be performed in parallel. This parallelization is possible because of the inclusion of DNA 'tags', or 'barcodes,' into each mutant, with the barcode serving as a proxy for the mutation and one can measure the barcode abundance to assess mutant fitness. In this study, we seek to fill the gap between DNA sequence and barcoded mutant collections. To accomplish this we introduce a combined transposon disruption-barcoding approach that opens up parallel barcode assays to newly sequenced, but poorly characterized microbes. To illustrate this approach we present a new Candida albicans barcoded disruption collection and describe how both microarray-based and next generation sequencing-based platforms can be used to collect 10,000 - 1,000,000 gene-gene and drug-gene interactions in a single experiment.

We have developed comprehensive, unbiased genome-wide screens to understand gene-drug and gene-environment interactions. Methods for screening these mutant collections are presented.

Écrans concurrentiel des bibliothèques génomiques de levure Barcoded

By virtue of advances in next generation sequencing technologies, we have access to new genome sequences almost daily.  The tempo of these advances is ...

DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

In vivo methods such as ChIP-chip are well-established techniques used to determine global gene targets for transcription factors. However, they are of limited use in exploring bacterial two component regulatory systems with uncharacterized activation conditions. Such systems regulate transcription only when activated in the presence of unique signals. Since these signals are often unknown, the in vitro microarray based method described in this video article can be used to determine gene targets and binding sites for response regulators. This DNA-affinity-purified-chip method may be used for any purified regulator in any organism with a sequenced genome. The protocol involves allowing the purified tagged protein to bind to sheared genomic DNA and then affinity purifying the protein-bound DNA, followed by fluorescent labeling of the DNA and hybridization to a custom tiling array. Preceding steps that may be used to optimize the assay for specific regulators are also described. The peaks generated by the array data analysis are used to predict binding site motifs, which are then experimentally validated. The motif predictions can be further used to determine gene targets of orthologous response regulators in closely related species. We demonstrate the applicability of this method by determining the gene targets and binding site motifs and thus predicting the function for a sigma54-dependent response regulator DVU3023 in the environmental bacterium Desulfovibrio vulgaris Hildenborough.

DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

This video article describes an in vitro microarray based method to determine the gene targets and binding sites for two component system response regulators.

ADN purifié par affinité Chip (DAP-puce) Méthode pour déterminer les cibles génétiques pour bactérienne Deux systèmes de réglementation composants

In vivo methods such as ChIP-chip are well-established techniques used to determine global gene targets for transcription factors. However, they are of ...

Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants

Array CGH for the detection of genomic copy number variants has replaced G-banded karyotype analysis. This paper describes the technology and its application in a clinical diagnostic service laboratory. DNA extracted from a patient&#8217;s sample (blood, saliva or other tissue types) is labeled with a fluorochrome (either cyanine 5 or cyanine 3). A reference DNA sample is labeled with the opposite fluorochrome. There follows a cleanup step to remove unincorporated nucleotides before the labeled DNAs are mixed and resuspended in a hybridization buffer and applied to an array comprising ~60,000 oligonucleotide probes from loci across the genome, with high probe density in clinically important areas. Following hybridization, the arrays are washed, then scanned and the resulting images are analyzed to measure the red and green fluorescence for each probe. Software is used to assess the quality of each probe measurement, calculate the ratio of red to green fluorescence and detect potential copy number variants.

Array Comparative Genomic Hybridization Array CGH for Detection of Genomic Copy Number Variants

Array CGH for the detection of genomic copy number variants has replaced G-banded karyotype analysis. This paper describes the technology and its application in a diagnostic service laboratory.

Démonstration technique de l'hybridation tableau Whole Genome génomique comparative

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