Queremos agradecer a los miembros del equipo Wan Lam matriz Laboratorio BAC especialmente Miwa Suzuki y Chi Bryan para la preparación de este artículo. Este trabajo fue financiado por los fondos de los Institutos Canadienses de Investigación en Salud, Canadá Genoma / Genoma Columbia Británica, y el NIH / NIDCR subvención RO1 DE15965-01.

SONDA DE ETIQUETADO Nota: limitar la exposición de tintes Cye a la luz en todo momento (esto se puede lograr mediante el trabajo en un área oscura o mediante el blindaje de los tubos con una cubierta como una lámina de aluminio) <ol><li> Combine: (Instalación de un tubo de reacción de referencia y un tubo de reacción de la muestra) <ul><li> ADN (25-400 ng) </li><li> 5 l de tampón 5X cebadores aleatorios (concentración final: 5 veces Promega Klenow de amortiguación y 7 mg / l octamers al azar) </li><li> Diluir a 17,0 l de volumen total con H 2 O destilada </li></ul></li><li> Hervir durante 10 minutos a 100 ° C. Inmediatamente en hielo durante 1 minuto. </li><li> Agregar 4 L de 10 veces la mezcla de dNTP (2 mM dATP, dGTP, dTTP, dCTP 1,2 mm). </li><li> Añadir CyeDyes: <ul><li> Añadir 2 l (2 nmoles) de Cy-3 dCTP marcado con el ADN de muestras </li><li> Añadir 2 l (2 nmoles) de Cy-5 dCTP marcado con ADN de referencia (por ejemplo, el ADN genómico humano Novagen) </li></ul></li><li> Añadir 2,5 l de Klenow (9 U / l, Promega) y mezclar. </li><li> Se incuba a 37 ° C durante la noche * (~ 18 horas). * El tiempo de hibridación noche a la mañana puede ser ajustado entre 14 a 24 horas sin afectar negativamente el proceso de etiquetado para ajustarse a un horario de laboratorio. </li></ol> Limpieza de la muestra (Combinado sonda de limpieza y preparación para la hibridación) <ol><li> El uso de un Microcon YM-30 columnas: <ul><li> Añadir 100 Cot-1 l de ADN (1μg/μL) a la columna. No toque la membrana con la punta de la pipeta. </li><li> Piscina de las reacciones (y muestra) y añadir a la columna. </li><li> Colocar la columna en el tubo siempre y giran a 13.000 g durante 10 minutos. </li><li> Añadir 200 l de H 2 0 destilada a la membrana y repita el giro de lavar. </li><li> Deseche el tubo y añadir solución de hibridación 45 l: (Roche DIG Easy) </li></ul> Opcional: añadir 5μL arenque cortado ADN de los espermatozoides (unidad 10μg/μL, Promega) <ul><li> Invertir Microcon, colocarlos en un tubo nuevo etiquetado, y giran a 3000 g por 3 minutos. </li></ul></li></ol> CÁLCULO DE INCORPORACIONES <ol><li> Quitar 1,5 l y la incorporación medida fluoróforo con espectrofotómetro NanoDrop. Usando su tampón de hibridación como un espacio en blanco (DIG Easy), siga las instrucciones en la pantalla. (Usted puede recuperar la muestra del pedestal, si es necesario, después de la medición.) (Nota:. Incorporaciones por debajo de 3,0 pmol / l en cualquiera de los canales han mostrado resultados variables) </li><li> Desnaturaliza a 85 ° C durante 10 minutos. </li><li> Coloque la sonda a 45 ° C durante 30 minutos a 1 hora (permite Cot-1 ADN recocido.) </li></ol> ARRAY HIBRIDACIÓN <ol><li> Lugar 44 l solución sonda en el cubreobjetos (22 mm x 60 mm) (Fisher Scientific). Si es posible, colocar el cubreobjetos sobre un portaobjetos caliente o bloque de calor pre-calentado a 45 ° C para mantener la temperatura. </li><li> Alinear a deslizarse sobre cubreobjetos y solución de la sonda, baja uno de los bordes de la diapositiva permite el contacto con la solución de hibridación. Continúe bajando hasta que el cubreobjetos se adjunta a la diapositiva con la tensión superficial. Invertir diapositivas. </li><li> Colocar la placa en casete de hibridación (Telechem), pre-calentado a 45 ° C, y se añaden 10 l de agua en el surco menor (para controlar la humedad durante la hibridación). </li><li> Sello de cassette y se incuba durante 36 a 40 horas a 45 ° C. </li></ol> ARRAY DE LAVADO Nota: Todas las soluciones de lavado se encuentran en un pH de 7,0 La eliminación de la diapositiva de la cassette de la hibridación es fundamental. DIG fácil cristaliza rápidamente a temperatura ambiente. La diapositiva debe ser inmediatamente sumergido y el cubreobjetos eliminado en la solución de lavado. <ol><li> Añadir aproximadamente 60 ml de 0.1XSSC, 0,1% SDS (pH 7.0, 45 ° C) la solución de lavado a una jarra de Coplin antes de abrir la cámara de hibridación. </li><li> Abrir la cámara, añadir diapositivas a la solución de lavado y eliminar cubreobjetos (debe deslizar). </li><li> Lave el carro 3 veces en 0.1XSSC + 0,1% SDS a 45 ° C durante 1 minuto con agitación. </li><li> Lave la lámina 3 veces en 0.1XSSC fresco *. No debe haber burbujas residuales del lavado de SDS visible. * Las diapositivas pueden permanecer en la solución de lavado final hasta que esté listo para centrifugar y análisis (~ 15 minutos). </li><li> Centrifugar la diapositiva en un tubo Falcon de 50 ml a 700 g por 3 minutos. </li><li> Inmediatamente escaneo de las diapositivas (intensidad de la señal disminuirá con el tiempo.) </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>

ADN de mala calidad no proporcionan un perfil de hibridación bien. Es esencial para asegurar que la muestra de ADN de referencia y están libres de contaminantes tales como el ARN fenol, sal, etc, que pueden interferir con el paso de etiquetado primer azar antes de iniciar un experimento de hibridación. Por ejemplo, la resuspensión de ADN en Tris - EDTA (TE) en lugar de agua no se recomienda como alta concentración de sal puede inhibir la reacción de marcaje. Se recomienda ensayar la calidad del ADN utilizando el espectrofotómetro Nan...

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		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
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<tr>
<td>5X Klenow Buffer</td>
<td>Reagent</td>
<td>Promega</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Random Octamers </td>
<td>Reagent</td>
<td>Alpha DNA</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>10X dNTP mix</td>
<td>Reagent</td>
<td>Promega</td>
<td>&nbsp;</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>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Cy-5 labeled dCTP</td>
<td>Reagent</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Human Genomic DNA Reference</td>
<td>Reagent</td>
<td>Novagen</td>
<td>&nbsp;</td>
<td>Example of a possible reference</td>
</tr>
<tr>
<td>Klenow</td>
<td>Reagent</td>
<td>Promega</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>YM-30 Column</td>
<td>Reagent</td>
<td>Millipore</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Cot-1 DNA</td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>DIG Easy</td>
<td>Reagent</td>
<td>Roche</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Sheared Herring Sperm DNA</td>
<td>Reagent</td>
<td>Promega</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Coverslip</td>
<td>Reagent</td>
<td>Fisher Scientific</td>
<td>&nbsp;</td>
<td>22mm x 60mm</td>
</tr>
<tr>
<td>Hybridization Cassette</td>
<td>Tool</td>
<td>Telechem</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

technical demonstration of whole genome array comparative genomic hybridization

Hibridación amplia genómica comparada (CGH array) es un método para la detección de pérdidas y ganancias de los segmentos de ADN o la dosis del gen en el genoma de uno. Los recientes avances en esta tecnología han permitido la comparación de alta resolución de todo el genoma para la identificación de alteraciones genéticas en el cáncer y otras enfermedades genéticas 2. La Sub-Megabase Resolución mosaico conjunto de matriz (o SMRT) serie se compone de un conjunto de aproximadamente treinta mil superposición de cromosomas artificiales bacterianos (BAC) clones que abarcan todo el genoma humano en ~ 100 pares de kilobases (kb) segmentos 2. Estos objetivos son BAC individual sintetizados y manchado por duplicado en un portaobjetos de vidrio solo 2-4. Array CGH se basa en el principio de la hibridación de la competencia. Muestra de ADN de referencia y son diferencialmente etiquetados con cianina-3 y colorantes cianina-5 fluorescentes, y co-hibridizada a la matriz. Después de un período de incubación de las muestras no unidos son lavados de la diapositiva y la matriz es fotografiado. Un paquete de software a libre disposición denominado SeeGH (www.flintbox.ca) se utiliza para procesar el gran volumen de datos recopilados - un solo experimento genera 53.892 puntos de datos. SeeGH visualiza la señal log2 relación de intensidad entre las dos muestras en cada objetivo BAC, que se alinea verticalmente con la posición de los cromosomas 5,6. La matriz SMRT puede detectar alteraciones tan pequeños como 50 kb de tamaño 7. La matriz SMRT puede detectar una variedad de eventos de reordenamiento del ADN incluyendo las ganancias de ADN, las pérdidas, amplificaciones y deleciones homocigóticas. Una ventaja única de la matriz SMRT es que uno puede usar el ADN aislado de las muestras en formol fija parafina embebidos. Cuando se combina con los requisitos de entrada bajos de ADN amplificado (25-100 ng) esto permite que el perfil de las muestras preciosas tales como los producidos por microdisección 7,8. Esto se atribuye al gran tamaño de cada objeto de la hibridación BAC, que permite la unión de suficientes muestras etiquetadas para producir las señales para la detección. Otra de las ventajas de esta plataforma es la tolerancia de la heterogeneidad del tejido, la disminución de la necesidad de microdisección de tejidos tedioso 8. Este protocolo de vídeo es un tutorial paso a paso de etiquetado de la entrada de ADN a través de adquisición de señal para el conjunto del genoma mosaico toda SMRT camino.

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

Este video es una demostración técnica del protocolo de hibridación para todo el genoma amplia baldosas CGH camino, que escanea todo el genoma humano utilizando sólo 25 a 100 ng de ADN que se puede aislar de una variedad de fuentes, incluyendo archivos de material fijado en formol.

Demostración de técnicas de hibridación del genoma entero matriz Genómica Comparativa

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

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

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

Video: Technical Demonstration of Whole Genome Array Comparative Genomic Hybridization

Double Whole Mount in situ Hybridization of Early Chick Embryos

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  gene expression in brain, neural tube, somite and heart primordia formation. This video demonstrates the different steps in 2-color whole mount in situ hybridization; First, the embryo is dissected from the egg and fixed in paraformaldehyde. Second, the embryo is processed for prehybridization. The embryo is then hybridized with two different probes, one coupled to DIG, and one coupled to FITC.  Following overnight hybridization, the embryo is incubated with DIG coupled antibody. Color reaction for DIG substrate is performed, and the region of interest appears blue. The embryo is then incubated with FITC coupled antibody. The embryo is processed for color reaction with FITC, and the region of interest appears red. Finally, the embryo is fixed and processed for phtograph and sectioning. A troubleshooting guide is also presented.

This video demonstrates 2-color whole mount in situ hybridization, a method by which the spatial and temporal expression pattern of 2 different genes can be visualized in young chick embryos. This method was originally introduced by David Wilkinson, Domingos Henrique, Phil Ingham and David Ish -Horowicz.

Monte doble entero hibridación in situ de embriones de pollo temprano

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Investigación

Biología

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. The protocol is a modified version of the standard in situ hybridization using alkaline phosphatase and substrates such as NBT/BCIP and Fast Red 1,2. This protocol utilizes standard digoxygenin and fluorescein labeled probes along with tyramide signal amplification (TSA) 3. The commercially available TSA kits allow flexible experimental design as fluorescence emission from green to far-red can be used in combination with various nuclear stains, such as propidium iodide, or fluorescence immunohistochemistry for proteins. TSA produces a reactive fluorescent substrate that quickly covalently binds to moieties, typically tyrosine residues, in the immediate vicinity of the labeled antisense riboprobe. The resulting staining patterns are high resolution in that subcellular localization of the mRNA can be observed using laser scanning confocal microscopy 3,4. One can observe nascent transcripts at the chromosomal loci, distinguish nuclear and cytoplasmic staining and visualize other patterns such as cortical localization of mRNA. Studies in Drosophila indicate that roughly 70% of mRNAs exhibit specific patterns of subcellular localization that frequently correlate with the function of the encoded protein 5. When combined with computer-aided reconstruction of 3D confocal datasets, our protocol allows the detailed analysis of mRNA distribution with sub-cellular resolution in whole vertebrate embryos.

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. We include a propidium iodide nuclear counter-stain to highlight tissue organization.

Pez cebra todo el montaje de alta resolución doble fluorescente In Situ La hibridación

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology.  Here, we present a high-resolution double ...

Using Whole Mount in situ Hybridization to Link Molecular and Organismal Biology

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of specific mRNA transcripts within whole mount specimen. This technique (adapted from Albertson and Yelick, 2005) was used in an upper level undergraduate Comparative Vertebrate Biology laboratory classroom at Syracuse University. The first two thirds of the Comparative Vertebrate Biology lab course gave students the opportunity to study the embryology and gross anatomy of several organisms representing various chordate taxa primarily via traditional dissections and the use of models. The final portion of the course involved an innovative approach to teaching anatomy through observation of vertebrate development employing molecular techniques in which WISH was performed on zebrafish embryos. A heterozygous fibroblast growth factor 8 a (fgf8a) mutant line, ace, was used. Due to Mendelian inheritance, ace intercrosses produced wild type, heterozygous, and homozygous ace/fgf8a mutants in a 1:2:1 ratio. RNA probes with known expression patterns in the midline and in developing anatomical structures such as the heart, somites, tailbud, myotome, and brain were used. WISH was performed using zebrafish at the 13 somite and prim-6 stages, with students performing the staining reaction in class. The study of zebrafish embryos at different stages of development gave students the ability to observe how these anatomical structures changed over ontogeny. In addition, some ace/fgf8a mutants displayed improper heart looping, and defects in somite and brain development. The students in this lab observed the normal development of various organ systems using both external anatomy as well as gene expression patterns. They also identified and described embryos displaying improper anatomical development and gene expression (i.e., putative mutants).
For instructors at institutions that do not already own the necessary equipment or where funds for lab and curricular innovation are limited, the financial cost of the reagents and apparatus may be a factor to consider, as will the time and effort required on the part of the instructor regardless of the setting. Nevertheless, we contend that the use of WISH in this type of classroom laboratory setting can provide an important link between developmental genetics and anatomy. As technology advances and the ability to study organismal development at the molecular level becomes easier, cheaper, and increasingly popular, many evolutionary biologists, ecologists, and physiologists are turning to research strategies in the field of molecular biology. Using WISH in a Comparative Vertebrate Biology laboratory classroom is one example of how molecules and anatomy can converge within a single course. This gives upper level college students the opportunity to practice modern biological research techniques, leading to a more diversified education and the promotion of future interdisciplinary scientific research.

Using Whole Mount in situ Hybridization to Link Molecular and Organismal Biology

Whole mount in situ hybridization (WISH) was used in an upper level undergraduate Comparative Vertebrate Biology course in addition to vertebrate dissections. This gave students the opportunity to study gene expression patterns as well as gross anatomy, linking the study of molecular and organismal biology within one course.

Todo el montaje utilizando In situ La hibridación de Enlace de Organismos y Biología Molecular

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of ...

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.

Microarrays de ADN: Control de calidad de la muestra, la hibridación de la matriz y de escaneo

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

Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos

Whole mount in situ hybridization is a very informative approach for defining gene expression patterns in embryos. The in situ hybridization procedures are lengthy and technically demanding with multiple important steps that collectively contribute to the quality of the final result. This protocol describes in detail several key quality control steps for optimizing probe labeling and performance. Overall, our protocol provides a detailed description of the critical steps necessary to reproducibly obtain high quality results. First, we describe the generation of digoxygenin (DIG) labeled RNA probes via in vitro transcription of DNA templates generated by PCR. We describe three critical quality control assays to determine the amount, integrity and specific activity of the DIG-labeled probes. These steps are important for generating a probe of sufficient sensitivity to detect endogenous mRNAs in a whole mouse embryo. In addition, we describe methods for the fixation and storage of E8.5-E11.5 day old mouse embryos for in situ hybridization. Then, we describe detailed methods for limited proteinase K digestion of the rehydrated embryos followed by the details of the hybridization conditions, post-hybridization washes and RNase treatment to remove non-specific probe hybridization. An AP-conjugated antibody is used to visualize the labeled probe and reveal the expression pattern of the endogenous transcript. Representative results are shown from successful experiments and typical suboptimal experiments.

Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos

This whole mount in situ hybridization protocol discusses critical steps that ensure reproducible high quality results for gene expression studies in E8.5-E11.5 day old mouse embryos.

Todo el monte In Situ La hibridación de E8.5 a E11.5 embriones de ratón

Whole mount in situ hybridization is a very informative approach for defining gene expression patterns in embryos. The in situ hybridization procedures ...

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.

Pantallas competitiva Genómica de Bibliotecas de levadura con código de barras

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

Detection of Rare Genomic Variants from Pooled Sequencing Using SPLINTER

As DNA sequencing technology has markedly advanced in recent years2, it has become increasingly evident that the amount of genetic variation between any two individuals is greater than previously thought3. In contrast, array-based genotyping has failed to identify a significant contribution of common sequence variants to the phenotypic variability of common disease4,5. Taken together, these observations have led to the evolution of the Common Disease / Rare Variant hypothesis suggesting that the majority of the "missing heritability" in common and complex phenotypes is instead due to an individual's personal profile of rare or private DNA variants6-8. However, characterizing how rare variation impacts complex phenotypes requires the analysis of many affected individuals at many genomic loci, and is ideally compared to a similar survey in an unaffected cohort. Despite the sequencing power offered by today's platforms, a population-based survey of many genomic loci and the subsequent computational analysis required remains prohibitive for many investigators.
To address this need, we have developed a pooled sequencing approach1,9 and a novel software package1 for highly accurate rare variant detection from the resulting data. The ability to pool genomes from entire populations of affected individuals and survey the degree of genetic variation at multiple targeted regions in a single sequencing library provides excellent cost and time savings to traditional single-sample sequencing methodology. With a mean sequencing coverage per allele of 25-fold, our custom algorithm, SPLINTER, uses an internal variant calling control strategy to call insertions, deletions and substitutions up to four base pairs in length with high sensitivity and specificity from pools of up to 1 mutant allele in 500 individuals. Here we describe the method for preparing the pooled sequencing library followed by step-by-step instructions on how to use the SPLINTER package for pooled sequencing analysis (<a href="http://www.ibridgenetwork.org/wustl/splinter" target="_blank">http://www.ibridgenetwork.org/wustl/splinter</a>). We show a comparison between pooled sequencing of 947 individuals, all of whom also underwent genome-wide array, at over 20kb of sequencing per person. Concordance between genotyping of tagged and novel variants called in the pooled sample were excellent. This method can be easily scaled up to any number of genomic loci and any number of individuals. By incorporating the internal positive and negative amplicon controls at ratios that mimic the population under study, the algorithm can be calibrated for optimal performance. This strategy can also be modified for use with hybridization capture or individual-specific barcodes and can be applied to the sequencing of naturally heterogeneous samples, such as tumor DNA.

Pooled DNA sequencing is a fast and cost-effective strategy to detect rare variants associated with complex phenotypes in large cohorts. Here we describe the computational analysis of pooled, next-generation sequencing of 32 cancer-related genes using the SPLINTER software package. This method is scalable, and applicable to any phenotype of interest.

La detección de raras variantes genómicas de secuenciación agruparon mediante SPLINTER

As DNA sequencing technology has markedly advanced in recent years2, it has become increasingly evident that the amount of genetic variation between any ...

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Assessing the expression pattern of a gene, as well as the subcellular localization properties of its transcribed RNA, are key features for understanding its biological function during development. RNA in situ hybridization (RNA-ISH) is a powerful method used for visualizing RNA distribution properties, be it at the organismal, cellular or subcellular levels 1. RNA-ISH is based on the hybridization of a labeled nucleic acid probe (e.g. antisense RNA, oligonucleotides) complementary to the sequence of an mRNA or a non-coding RNA target of interest 2. As the procedure requires primary sequence information alone to generate sequence-specific probes, it can be universally applied to a broad range of organisms and tissue specimens 3. Indeed, a number of large-scale ISH studies have been implemented to document gene expression and RNA localization dynamics in various model organisms, which has led to the establishment of important community resources 4-11. While a variety of probe labeling and detection strategies have been developed over the years, the combined usage of fluorescently-labeled detection reagents and enzymatic signal amplification steps offer significant enhancements in the sensitivity and resolution of the procedure 12. Here, we describe an optimized fluorescent in situ hybridization method (FISH) employing tyramide signal amplification (TSA) to visualize RNA expression and localization dynamics in staged Drosophila embryos. The procedure is carried out in 96-well PCR plate format, which greatly facilitates the simultaneous processing of large numbers of samples.

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Here we describe a whole-mount fluorescent in situ hybridization (FISH) protocol for determining the expression and localization properties of RNAs expressed during embryogenesis in the fruit fly, Drosophila melanogaster.

Todo el monte ARN fluorescente<em&gt; In situ</em&gt; La hibridación de<em&gt; Drosophila</em&gt; Los embriones

Assessing  the expression pattern of a gene, as well as the subcellular localization  properties of its transcribed RNA, are key features for ...

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.

Matriz de hibridación genómica comparada (CGH array) para la detección de número de copias genómicas variantes

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

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors&#160;induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA, removal of remaining linear chromosomal DNA, rolling-circle amplification of eccDNA, deep sequencing, and mapping. Extensive exonuclease treatment&#160;was&#160;required for sufficient linear chromosomal DNA degradation. The rolling-circle amplification step by &#966;29 polymerase enriched for circular DNA over linear DNA. Validation of the Circle-Seq method on three S. cerevisiae CEN.PK populations of 1010 cells detected hundreds of eccDNA profiles in sizes larger than 1 kilobase. Repeated findings of ASP3-1, COS111, CUP1, RSC30,&#160;HXT6, HXT7 genes on circular DNA in both S288c and CEN.PK suggests that DNA circularization is conserved between strains at these loci. In sum, the Circle-Seq method has broad applicability for genome-scale screening for eccDNA in eukaryotes as well as for detecting specific eccDNA types.

This paper presents a sensitive method called Circle-Seq for purifying extrachromosomal circular DNA (eccDNA). The method encompasses column purification, removal of remaining linear chromosomal DNA, rolling-circle amplification and high-throughput sequencing. Circle-Seq is applicable to genome-scale screening of eukaryotic eccDNA and studying genome instability and copy-number variation.

La purificación de todo el genoma de ADN circular Extracromosómica a partir de células eucariotas

Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs ...

Demostración de técnicas de hibridación del genoma entero matriz Genómica Comparativa

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