Este trabajo fue realizado por estudiantes de pregrado en Southwestern Oklahoma State University, OK Weatherford. Este trabajo fue apoyado por la NSF Rui-0963258, NIH OK INBRE 2P20RR016478, GCAT y OCAST HR09-137S. El vsm1 (ok1468) mutante fue aislado por el Consorcio golpe de gracia Oklahoma Gene. Los autores agradecen a Dan Wheeler Stefanovic y Tanner por su valiosa ayuda durante la ejecución del proyecto.

<ol>
	<li>Chai, A., Withers, J., Koh, Y. H., Parry, K., Bao, H., Zhang, B., Budnik, V., Pennetta, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=hVAPB,+the+causative+gene+of+a+heterogeneous+group+of+motor+neuron+diseases+in+humans,+is+functionally+interchangeable+with+its+Drosophila+homologue+DVAP-33A+at+the+Neuromuscular+Junction.">hVAPB, the causative gene of a heterogeneous group of motor neuron diseases in humans, is functionally interchangeable with its Drosophila homologue DVAP-33A at the Neuromuscular Junction.</a> Hum Mol Genet. 17, 266-280 (2008).</li><li>Tsuda, H., Han, S. M., Yang, Y., Tong, C., Lin, Y. Q., Mohan, K., Haueter, C., Zoghbi, A., Harati, Y., Kwan, J., Miller, M., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Amyotrophic+Lateral+Sclerosis+8+protein+VAPB+is+cleaved,+secreted,+and+acts+as+a+ligand+for+Eph+receptors.">The Amyotrophic Lateral Sclerosis 8 protein VAPB is cleaved, secreted, and acts as a ligand for Eph receptors.</a> Cell. 133, 963-977 (2008).</li><li>Dresbach, T., Torres, V., Wittenmayer, N., Altrock, W. D., Zamorano, P., Zuschratter, W., Nawrotzki, R., Ziv, N. E., Garner, C. C., Gundelfinger, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+of+Active+Zone+Precursor+Vesicles.">Assembly of Active Zone Precursor Vesicles.</a> Journal of Biological Chemistry. 281, 6038-6047 (2005).</li><li>Lustgarten, V., Gerst, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Yeast+VSM1+Encodes+a+v-SNARE+Binding+Protein+That+May+Act+as+a+Negative+Regulator+of+Constitutive+Exocytosis.">Yeast VSM1 Encodes a v-SNARE Binding Protein That May Act as a Negative Regulator of Constitutive Exocytosis.</a> Molecular and Cellular Biology. 19, 4480-4494 (1999).</li><li>Vi&#241;uela, A., Snoek, L., Riksen, J., Kammenga, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-Wide+Gene+Expression+Analysis+in+Response+to+Organophosphorous+Pesticide+Chlorpyrifos+and+Diazinon+in+C.+elegans.">Genome-Wide Gene Expression Analysis in Response to Organophosphorous Pesticide Chlorpyrifos and Diazinon in C. elegans.</a> PloS one. 5, 1-8 (2010).</li><li>Niwa, R., Hada, K., Moliyama, K., Ohniwa, R., Tan, Y., Olsson-Carter, K., Chi, W., Reinke, V., Slack, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=elegans+sym-1+is+downstream+target+of+the+hunchback-like-1+developmental+timing+transcription+factor.">elegans sym-1 is downstream target of the hunchback-like-1 developmental timing transcription factor.</a> Cell Cycle. 8, 4147-4154 (2009).</li><li>Kershner, A., Kimble, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-wide+analysis+of+mRNA+targets+for+Caenorhabditis+elegans+FBF,+a+conserved+stem+cell+regulator.">Genome-wide analysis of mRNA targets for Caenorhabditis elegans FBF, a conserved stem cell regulator.</a> PNAS. 107, 3963-3941 (2010).</li><li>Hammock, E., Eagleson, K., Barlow, S., Earls, L., Miller, D., Levitt, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Homologs+of+genes+expressed+in+Caenorhabditis+elegans+GABAergic+neurons+are+also+found+in+the+developing+mouse+forebrain.">Homologs of genes expressed in Caenorhabditis elegans GABAergic neurons are also found in the developing mouse forebrain.</a> Neural Development. 5, 1-14 (2010).</li></ol>

No hay conflictos de interés declarado.

En este estudio se desarrolló un protocolo sencillo, fácil de usar que se puede utilizar para determinar perfiles de expresión genética subyacente varios fenómenos biológicos. En este protocolo, el ARN total fue aislado por primera vez y tratados con DNasa I. Nuestro método de aislamiento de ARN ha sido dramáticamente simplificadas omitiendo extracciones con fenol y el uso de resinas de afinidad para la limpieza 5,6. En pocas palabras, C. elegans membranas cuticulares y células estaban rotas, abiertas por los nematodos congelación con nitrógeno líquido y la molienda con resina molecular. A continuación, extrae el ARN fue tratado con DNasa I antes de la síntesis de ADNc. El paso posterior fue agregado a minimizar hibridaciones inespecíficas, las muestras de ARN contaminadas con ADN genómico podría introducir interferencias y producir muchos falsos positivos. Entonces, de tipo salvaje y VSM-1 (ok1468) ADNc mutantes fueron marcadas con Cy3 y Cy5 secuencias de captura y se hibridan en C. microarrays elegans obtiene a través del programa GCAT. Este sistema es más sensible que otros productos similares, y sus dos colores diseño reduce el número de arreglos necesarios, resultando en una mayor eficiencia de costes y el tiempo 7,8. Además, este sistema no requiere el equipo especializado de otros sistemas similares, por lo tanto, este procedimiento podría llevarse a cabo en cualquier entorno de laboratorio estándar 7. Imágenes en tercer lugar, fluorescentes conjunto híbrido fueron analizados utilizando el software de código abierto MAGICTool, y perfiles de expresión génica que fueron creados. MAGICTool es un programa fácil de usar que es fácilmente utilizada por personas de todos los niveles, desde el pregrado a la post-doctorado. Sin embargo, un funcionamiento óptimo requiere la disponibilidad de grandes cantidades de memoria. Por último, los genes candidatos obtuvieron mediante el análisis de microarrays fueron validados con PCR en tiempo real. Aunque el enfoque genómico es un método eficaz para el estudio de los fenómenos biológicos, hay algunas limitaciones hay que tener en cuenta. En primer lugar, a pesar de la especificidad de este protocolo de microarrays, transcripciones dentro de una familia no se distinguen el uno del otro si el oligonucleótido impreso se ha tomado de secuencias conservadas. PCR en tiempo real compensa similitudes dentro de una familia de genes, e incluso se puede distinguir entre las isoformas específicas del mismo gen. Sin embargo, con PCR en tiempo real es un desafío para encontrar los controles de verdad que se expresan por igual durante toda la vida de un organismo. Debido a esto, los resultados serán relativos. Una aproximación proteómica es una alternativa a nuestra técnica. Proteínas individuales se pueden aislar mediante electroforesis en gel 2D y se identifica con la espectrometría de masas. Nuestros estudios muestran específicamente que los miembros de muchas de las principales proteínas de los espermatozoides (MSP) de la familia son inducidos en VSM-1 nematodos mutantes con una mayor densidad sináptica. MSPs son exclusivas de C. elegans y son responsables de la maduración de oocitos y la ovulación. Chai 1 ha demostrado que la regulación del número y tamaño bouton presináptica en la unión neuromuscular en moscas de la fruta es probable controlada por moléculas que contienen grandes dominios de proteínas de esperma. Los estudios realizados por Tsuda y sus colegas han demostrado dos grandes dominios de la proteína de esperma puede servir como ligandos para los receptores Ephrine, provocando cascadas de señalización del receptor de la tirosina cinasa. Por otra parte, el análisis en tiempo real PCR validados y se redujeron los resultados de microarrays de un miembro de la familia msp, msp-32. En conjunto, el trabajo presentado aquí representa un análisis de todo el genoma de un dilema central de la neurociencia, así como el poder de la investigación de pregrado en el quehacer científico.

<table border="1"><tbody><tr><td> Componente </td><td> Catálogo # </td><td> Empresa </td></tr><tr><td> Más tarde, el ARN </td><td> AM7020 </td><td> Ambion </td></tr><tr><td> Resina molecular de molienda </td><td> 786-138 </td><td> Gbiosciences </td></tr><tr><td> RNeasy Mini Kit </td><td> 74104 </td><td> Qiagen </td></tr><tr><td> RNasa libre de agarosa LE </td><td> AM9040 </td><td> Ambion </td></tr><tr><td> NorthernMax Gly 10X Gel de preparación / ejecución de Buffer </td><td> 8678 </td><td> Ambion </td></tr><tr><td> ARN del Milenio marcador </td><td> AM7150 </td><td> Ambion </td></tr><tr><td> Glioxal muestra colorante de carga </td><td> 8551 </td><td> Ambion </td></tr><tr><td> DNasa conjunto </td><td> 79254 </td><td> Qiagen </td></tr><tr><td> RNeasy MinElute Kit </td><td> 74204 </td><td> Qiagen </td></tr><tr><td> RT enzima y tampón de reacción 5X </td><td> RT300320 </td><td> Genisphere </td></tr><tr><td> Matriz de 350 </td><td> W300180 </td><td> Genisphere </td></tr><tr><td> QIAquick PCR kit de purificación </td><td> 28104 </td><td> Qiagen </td></tr><tr><td> 20X SSC </td><td> 82021-4846 </td><td> VWR </td></tr><tr><td> Salmón cortado ADN de los espermatozoides </td><td> AM9680 </td><td> Ambion </td></tr><tr><td> SDS solución </td><td> V6551 </td><td> Promega </td></tr><tr><td> TDT EM </td><td> 3860 </td><td> VWR </td></tr><tr><td> iScript Kit Síntesis de cDNA </td><td> 170-8890 </td><td> BioRad </td></tr><tr><td> iQ SYBR Green Supermix </td><td> 170-8880 </td><td> BioRad </td></tr></tbody></table>

determining genetic expression profiles in c. elegans using microarray and real-time pcr

Las sinapsis se componen de una zona presináptica activa en la señalización celular y una terminal postsináptica en la célula diana. En el caso de las sinapsis químicas, los mensajes son transportados por neurotransmisores liberados desde las terminales presinápticas y recibida por los receptores en las células postsinápticas. Nuestra investigación previa en Caenorhabditis elegans han demostrado que VSM-1 regula negativamente la exocitosis. Además, el análisis de las sinapsis en el VSM-1 mutantes mostraron que los animales que carecen de un completo y funcional de conectividad VSM-1 se han incrementado sináptica. En base a estos hallazgos preliminares, la hipótesis de que la C. elegans VSM-1 puede desempeñar un papel crucial en la sinaptogénesis. Para probar esta hipótesis, de doble etiquetado de análisis de microarrays se llevó a cabo, y los perfiles de expresión génica se determinaron. En primer lugar, se aisló ARN total, inversamente transcribe a cDNA, y se hibridan con los microarrays de ADN. Luego, en silico análisis de hibridación de la sonda fluorescente reveló una inducción significativa de muchos genes que codifican para los miembros de la familia de los espermatozoides principal proteína (MSP) en mutantes con una mayor sinaptogénesis. Proyectos son el principal componente de los espermatozoides en el C. elegans y parece que la señal de la maduración de los ovocitos de nematodos y la ovulación. En las moscas de la fruta, Chai y sus colegas demostraron que un MSP moléculas similares a regular el número y el tamaño de Bouton presináptica en la unión neuromuscular. Además, el análisis realizado por Tsuda y compañeros de trabajo 2 sugiere que los MSPs pueden actuar como ligandos para los receptores Eph y del receptor de activación de la tirosina cinasa cascadas de señalización. Por último, el análisis de PCR en tiempo real corroboró que el gen que codifica para MSP-32 es inducida en VSM-1 (ok1468) mutantes. En conjunto, la investigación realizada por nuestro laboratorio han demostrado que VSM-1 mutantes tienen un aumento significativo en la densidad sináptica, lo que podría estar mediado por el MSP-32 de señalización.

Watch this Scientific Journal Video about Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR at JoVE.com

Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR

Análisis de microarrays se realizó para determinar los perfiles de expresión génica en<em&gt; C. elegans</em&gt;, Y en tiempo real PCR se utilizó para validar y cuantificar los datos de microarrays.

La determinación de perfiles genéticos de expresión en C. elegans Utilización de microarrays y PCR en tiempo real

Synapses are composed of a presynaptic active zone in the signaling cell and a postsynaptic terminal in the target cell. In the case of chemical synapses, ...

determining-genetic-expression-profiles-c-elegans-using-microarray

Research

JoVE Journal

Biology

Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR

22.9K vistas.  Southwestern Oklahoma State University. Análisis de microarrays se realizó para determinar los perfiles de expresión génica en C. elegans, Y en tiempo real PCR se utilizó para validar y cuantificar los datos de microarrays.

Video: Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1. The plasmid DNA rearranges to form extrachromosomal concatamers that are stably inherited, though not with the same efficiency as actual chromosomes 2. A gene of interest is co-injected with an obvious phenotypic marker, such as rol-6 or GFP, to allow selection of transgenic animals under a dissecting microscope. The exogenous gene may be expressed from its native promoter for cellular localization studies. Alternatively, the transgene can be driven by a different tissue-specific promoter to assess the role of the gene product in that particular cell or tissue. This technique efficiently drives gene expression in all tissues of C. elegans except for the germline or early embryo 3. Creation of transgenic animals is widely utilized for a range of experimental paradigms. This video demonstrates the microinjection procedure to generate transgenic worms. Furthermore, selection and maintenance of stable transgenic C. elegans lines is described.

This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.

Generación de transgénicos estable C. elegans con microinyección

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

Investigación

Biología

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.

Gene mundial y Análisis de Expresión utilizando una plataforma de microarrays de oligonucleótidos de pez cebra

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

Quantitative Real-Time PCR using the Thermo Scientific Solaris qPCR Assay

The Solaris qPCR Gene Expression Assay is a novel type of primer/probe set, designed to simplify the qPCR process while maintaining the sensitivity and accuracy of the assay. These primer/probe sets are pre-designed to &gt;98% of the human and mouse genomes and feature significant improvements from previously available technologies. These improvements were made possible by virtue of a novel design algorithm, developed by Thermo Scientific bioinformatics experts.
Several convenient features have been incorporated into the Solaris qPCR Assay to streamline the process of performing quantitative real-time PCR. First, the protocol is similar to commonly employed alternatives, so the methods used during qPCR are likely to be familiar. Second, the master mix is blue, which makes setting the qPCR reactions easier to track. Third, the thermal cycling conditions are the same for all assays (genes), making it possible to run many samples at a time and reducing the potential for error. Finally, the probe and primer sequence information are provided, simplifying the publication process.
Here, we demonstrate how to obtain the appropriate Solaris reagents using the GENEius product search feature found on the ordering web site (www.thermo.com/solaris) and how to use the Solaris reagents for performing qPCR using the standard curve method.

The Solaris qPCR Gene Expression Assays are novel pre-designed qPCR primer/probe combinations designed to simplify the qPCR process without sacrificing the specificity and robustness of the assay.

Cuantitativas PCR en tiempo real utilizando el Thermo Scientific Solaris qPCR ensayo

The Solaris qPCR Gene Expression Assay is a novel type of primer/probe set, designed to simplify the qPCR process while maintaining the sensitivity and ...

Analysis of Gene Expression in Emerald Ash Borer (Agrilus planipennis) Using Quantitative Real Time-PCR

Emerald ash borer (EAB, Agrilus planipennis) is an exotic invasive pest, which has killed millions of ash trees (Fraxinus spp) in North America. EAB continues to spread rapidly and attacks ash trees of different ages, from saplings to mature trees. However, to date very little or no molecular knowledge exists for EAB. We are interested in deciphering the molecular-based physiological processes at the tissue level that aid EAB in successful colonization of ash trees. In this report we show the effective use of quantitative real-time PCR (qRT-PCR) to ascertain mRNA levels in different larval tissues (including midgut, fat bodies and cuticle) and different developmental stages (including 1st-, 2nd-, 3rd-, 4th-instars, prepupae and adults) of EAB. As an example, a peritrophin gene (herein named, AP-PERI1) is exemplified as the gene of interest and a ribosomal protein (AP-RP1) as the internal control. Peritrophins are important components of the peritrophic membrane/matrix (PM), which is the lining of the insect gut. The PM has diverse functions including digestion and mechanical protection to the midgut epithelium.

Analysis of Gene Expression in Emerald Ash Borer Agrilus planipennis Using Quantitative Real Time-PCR

Quantitative real-time PCR (qRT-PCR) is an effective tool to diagnose mRNA levels in different insect tissues and developmental stages. In this report we show the use of qRT-PCR to ascertain mRNA levels in different larval tissues and developmental stages of the invasive insect species, emerald ash borer.

Análisis de la expresión génica en el barrenador esmeralda del fresno ( Agrilus planipennis) Utilizando Real-PCR cuantitativa en tiempo

Emerald ash borer (EAB, Agrilus planipennis) is an exotic invasive pest, which has killed millions of ash trees (Fraxinus spp) in North America. EAB ...

Profiling of Pre-micro RNAs and microRNAs using Quantitative Real-time PCR (qPCR) Arrays

Quantitative real-time PCR (QPCR) has emerged as an accurate and valuable tool in profiling gene expression levels.  One of its many advantages is a lower detection limit compared to other methods of gene expression profiling while using smaller amounts of input for each assay.  Automated qPCR setup has improved this field by allowing for greater reproducibility.  Its convenient and rapid setup allows for high-throughput experiments, enabling the profiling of many different genes simultaneously in each experiment.  This method along with internal plate controls also reduces experimental variables common to other techniques.  
We recently developed a qPCR assay for profiling of pre-microRNAs  (pre-miRNAs) using a set of 186 primer pairs.  MicroRNAs have emerged as a novel class of small, non-coding RNAs with the ability to regulate many mRNA targets at the post-transcriptional level.  These small RNAs are first transcribed by RNA polymerase II as a primary miRNA (pri-miRNA) transcript, which is then cleaved into the precursor miRNA (pre-miRNA).  Pre-miRNAs are exported to the cytoplasm where Dicer cleaves the hairpin loop to yield mature miRNAs.  Increases in miRNA levels can be observed at both the precursor and mature miRNA levels and profiling of both of these forms can be useful.  There are several commercially available assays for mature miRNAs; however, their high cost may deter researchers from this profiling technique.  Here, we discuss a cost-effective, reliable, SYBR-based qPCR method of profiling pre-miRNAs.  Changes in pre-miRNA levels often reflect mature miRNA changes and can be a useful indicator of mature miRNA expression.  However, simultaneous profiling of both pre-miRNAs and mature miRNAs may be optimal as they can contribute nonredundant information and provide insight into microRNA processing.  Furthermore, the technique described here can be expanded to encompass the profiling of other library sets for specific pathways or pathogens.

Profiling of Pre-micro RNAs and microRNAs using Quantitative Real-time PCR qPCR Arrays

We will demonstrate the setup and analysis of pre-microRNA 96-well arrays for QPCR using a robot as well as by hand with a Thermo Scientific Matrix multichannel pipette.

Perfiles de Pre-micro ARN y microRNAs utilizando cuantitativa en tiempo real PCR (qPCR) Arrays

Quantitative real-time PCR (QPCR) has emerged as an accurate and valuable tool in profiling gene expression levels.  One of its many advantages is a lower ...

Biochemical and High Throughput Microscopic Assessment of Fat Mass in Caenorhabditis Elegans

The nematode C. elegans has emerged as an important model for the study of conserved genetic pathways regulating fat metabolism as it relates to human obesity and its associated pathologies. Several previous methodologies developed for the visualization of C. elegans triglyceride-rich fat stores have proven to be erroneous, highlighting cellular compartments other than lipid droplets. Other methods require specialized equipment, are time-consuming, or yield inconsistent results. We introduce a rapid, reproducible, fixative-based Nile red staining method for the accurate and rapid detection of neutral lipid droplets in C. elegans. A short fixation step in 40% isopropanol makes animals completely permeable to Nile red, which is then used to stain animals. Spectral properties of this lipophilic dye allow it to strongly and selectively fluoresce in the yellow-green spectrum only when in a lipid-rich environment, but not in more polar environments. Thus, lipid droplets can be visualized on a fluorescent microscope equipped with simple GFP imaging capability after only a brief Nile red staining step in isopropanol. The speed, affordability, and reproducibility of this protocol make it ideally suited for high throughput screens. We also demonstrate a paired method for the biochemical determination of triglycerides and phospholipids using gas chromatography mass-spectrometry. This more rigorous protocol should be used as confirmation of results obtained from the Nile red microscopic lipid determination. We anticipate that these techniques will become new standards in the field of C. elegans metabolic research.

Biochemical and High Throughput Microscopic Assessment of Fat Mass in Caenorhabditis Elegans

We present robust biochemical and microscopic methods for studying Caenorhabditis elegans lipid stores. A rapid, simple, fixing-staining procedure for fluorescent lipid droplet imaging leverages the spectral properties of the lipophilic dye Nile red. We then present biochemical measurement of triglycerides and phospholipids using solid phase extraction and gas chromatography-mass spectrometry.

Bioquímica y de Evaluación de Rendimiento microscópica de masa grasa en<em&gt; Caenorhabditis elegans</em

The nematode C. elegans has emerged as an important  model for the study of conserved genetic pathways regulating fat metabolism as  it relates to human ...

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

To stain C. elegans with antibodies, the relatively impermeable cuticle must be bypassed by chemical or mechanical methods. "Freeze-cracking" is one method used to physically pull the cuticle from nematodes by compressing nematodes between two adherent slides, freezing them, and pulling the slides apart. Freeze-cracking provides a simple and rapid way to gain access to the tissues without chemical treatment and can be used with a variety of fixatives. However, it leads to the loss of many of the specimens and the required compression mechanically distorts the sample. Practice is required to maximize recovery of samples with good morphology. Freeze-cracking can be optimized for specific fixation conditions, recovery of samples, or low non-specific staining, but not for all parameters at once. For antibodies that require very hard fixation conditions and tolerate the chemical treatments needed to chemically permeabilize the cuticle, treatment of intact nematodes in solution may be preferred. If the antibody requires a lighter fix or if the optimum fixation conditions are unknown, freeze-cracking provides a very useful way to rapidly assay the antibody and can yield specific subcellular and cellular localization information for the antigen of interest.

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

"Freeze-cracking," a method for exposing the inner tissues of the nematode C. elegans to antibodies for protein localization, is demonstrated.

Tinción de anticuerpos en<em&gt; C. Elegans</em&gt; Uso de &quot;Freeze-Cracking&quot;

To stain C.  elegans with antibodies, the relatively impermeable cuticle must be  bypassed by chemical or mechanical methods.  "Freeze-cracking" is one ...

Linear Amplification Mediated PCR &#8211; Localization of Genetic Elements and Characterization of Unknown Flanking DNA

Linear-amplification mediated PCR (LAM-PCR) has been developed to study hematopoiesis in gene corrected cells of patients treated by gene therapy with integrating vector systems. Due to the stable integration of retroviral vectors, integration sites can be used to study the clonal fate of individual cells and their progeny. LAM- PCR for the first time provided evidence that leukemia in gene therapy treated patients originated from provirus induced overexpression of a neighboring proto-oncogene. The high sensitivity and specificity of LAM-PCR compared to existing methods like inverse PCR and ligation mediated (LM)-PCR is achieved by an initial preamplification step (linear PCR of 100 cycles) using biotinylated vector specific primers which allow subsequent reaction steps to be carried out on solid phase (magnetic beads). LAM-PCR is currently the most sensitive method available to identify&#160;unknown DNA which is located in the proximity of known DNA. Recently, a variant of LAM-PCR has been developed that circumvents restriction digest thus abrogating retrieval bias of integration sites and enables a comprehensive analysis of provirus locations in host genomes. The following protocol explains step-by-step the amplification of both 3&#8217;- and 5&#8217;- sequences adjacent to the integrated lentiviral vector.

Linear Amplification Mediated PCR &amp;#8211; Localization of Genetic Elements and Characterization of Unknown Flanking DNA

Linear-amplification mediated (LAM)-PCR is a method developed to identify the exact positions of integrating viral vectors in the genome. The technique has evolved to be the superior method to study clonal dynamics in gene therapy patients, biosafety of novel vector technologies, T-cell diversity, cancer stem cell models, etc.

Lineal Amplificación Mediada por PCR - Localización de elementos genéticos y caracterización de ADN que flanquean Desconocido

Linear-amplification mediated PCR (LAM-PCR) has been developed to study hematopoiesis in gene corrected cells of patients treated by gene therapy with ...

Probe-based Real-time PCR Approaches for Quantitative Measurement of microRNAs

Probe-based quantitative PCR (qPCR) is a favoured method for measuring transcript abundance, since it is one of the most sensitive detection methods that provides an accurate and reproducible analysis. Probe-based chemistry offers the least background fluorescence as compared to other (dye-based) chemistries. Presently, there are several platforms available that use probe-based chemistry to quantitate transcript abundance. qPCR in a 96 well plate is the most routinely used method, however only a maximum of 96 samples or miRNAs can be tested in a single run. This is time-consuming and tedious if a large number of samples/miRNAs are to be analyzed. High-throughput probe-based platforms such as microfluidics (e.g. TaqMan Array Card) and nanofluidics arrays (e.g. OpenArray) offer ease to reproducibly and efficiently detect the abundance of multiple microRNAs in a large number of samples in a short time. Here, we demonstrate the experimental setup and protocol for miRNA quantitation from serum or plasma-EDTA samples, using probe-based chemistry and three different platforms (96 well plate, microfluidics and nanofluidics arrays) offering increasing levels of throughput.

Circulating microRNAs have recently emerged as promising and novel biomarkers for various cancers and other diseases. The goal of this article is to discuss three different probe-based real-time PCR platforms and methods that are available to quantify and determine the abundance of circulating microRNAs.

PCR en tiempo real basada en sondeos Enfoques para la medición cuantitativa de microRNAs

Probe-based quantitative PCR (qPCR) is a favoured method for measuring transcript abundance, since it is one of the most sensitive detection methods that ...

qPCRTag Analysis - A High Throughput, Real Time PCR Assay for Sc2.0 Genotyping

The Synthetic Yeast Genome Project (Sc2.0) aims to build 16 designer yeast chromosomes and combine them into a single yeast cell. To date one synthetic chromosome, synIII1, and one synthetic chromosome arm, synIXR2, have been constructed and their in vivo function validated in the absence of the corresponding wild type chromosomes. An important design feature of Sc2.0 chromosomes is the introduction of PCRTags, which are short, re-coded sequences within open reading frames (ORFs) that enable differentiation of synthetic chromosomes from their wild type counterparts. PCRTag primers anneal selectively to either synthetic or wild type chromosomes and the presence/absence of each type of DNA can be tested using a simple PCR assay. The standard readout of the PCRTag assay is to assess presence/absence of amplicons by agarose gel electrophoresis. However, with an average PCRTag amplicon density of one per 1.5 kb and a genome size of ~12 Mb, the completed Sc2.0 genome will encode roughly 8,000 PCRTags. To improve throughput, we have developed a real time PCR-based detection assay for PCRTag genotyping that we call qPCRTag analysis. The workflow specifies 500 nl reactions in a 1,536 multiwell plate, allowing us to test up to 768 PCRTags with both synthetic and wild type primer pairs in a single experiment.

Designer chromosomes of the Synthetic Yeast Genome project, Sc2.0, can be distinguished from their native counterparts using a PCR-based genotyping assay called PCRTagging, which has a presence/absence endpoint. Here we describe a high-throughput real time PCR detection method for PCRTag genotyping.

Análisis qPCRTag - Un alto rendimiento, Tiempo real ensayo PCR para Sc2.0 Genotipado

The Synthetic Yeast Genome Project (Sc2.0) aims to build 16 designer yeast chromosomes and combine them into a single yeast cell. To date one synthetic ...