Name: analysis of line-1 retrotransposition at the single nucleus level
Uploaded: 2016-04-23T14:00:00
Description: Watch this Scientific Journal Video about Analysis of LINE-1 Retrotransposition at the Single Nucleus Level at JoVE.com

This work was supported in part by grants from the National Institute of Environmental Health Sciences (ES014443 and ES017274) and AstraZeneca to KSR.

BEMÆRK: bør gennemføres Alle trin ud ved stuetemperatur, medmindre andet er angivet. Se reagenser afsnittet for detaljer om, hvordan man forbereder individuelle reagenser. 1. Mærkning L1 Probes BEMÆRK: Prober kan mærkes ved kemisk eller PCR mærkning. <ol><li> Kemisk mærkning <ol><li> Gør 0,7-1% agarosegel i Tris-acetat-EDTA (TAE) puffer, varme i en mikrobølgeovn indtil smeltet, tillade gelen at afkøle, og derefter tilføje e...

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Metoder såsom hele genomet sekventering, invers PCR og Southern blotting er blevet anvendt til at studere L1 retrotransposition. Selv om disse metoder er yderst værdifulde i lokalisering hvor L1 indrykninger forekomme inden genomer, en confounding udfordring for dem alle er behovet for in-silico programmering at samle sekvenser. FISH metode, der beskrives her, er designet til at supplere disse metoder, især i tilfælde af undersøgelser, der kræver analyser af ektopisk L1 retrotra...

Menneskelig Lang Afbrudt Nuclear Element-1 (Line-1 eller L1) er en selvstændig mobile element, der udbreder i genomet gennem en &quot;kopiere og indsætte&quot; retrotransposition mekanisme. En typisk human L1 er ~ 6 kb lang og består af en 5&#39;UTR (utranslateret region), der fungerer som en promotor, to åbne læserammer (ORF&#39;er): L1 -ORF1 og L1 -ORF2, og en 3&#39;UTR med en polyA . hale L1 -ORF1 protein har tre distinkte domæner: en coil domæne, RNA genkendelsesmotiv og C-terminale domæne, mens L1 -ORF2 protein har endonuklease, revers transkriptase og cysteinrige domæner 1,2,3,4,5. L1 -ORF1 udviser nukleinsyre ekskortere aktiviteter, mens L1 -ORF2 giver enzymatiske aktiviteter, med begge proteiner, der er nødvendige for retrotransposition 1,2,6. En cyklus af L1 retrotransposition starter med transkription fra 5&#39;UTR i L1 </em&gt; bicistronisk mRNA med RNA-polymerase II, translokation ind i cytoplasmaet, og oversættelse. I cytoplasmaet, at L1 -ORF1 udstiller enten cis -bindende hvor det pakker sin egen RNA eller trans -bindende hvor det pakker andre RNA (dvs., Sine / SVAS / pseudogener) danner en ribonukleoprotein partikel (RNP) med L1 -ORF2p 7, 8. RNP&#39;er translokerer ind i kernen, hvor endonukleaseaktiviteten af L1 -ORF2p nicks genomisk DNA (gDNA) for at blotlægge en OH - gruppe 9, der på sin side anvendes ved revers transkriptase til at prime og revers syntetisere RNA til DNA fra 3&#39;-enden. Under omvendt syntese, er den anden streng af DNA hakkede 7-20 bp fra den oprindelige nick stedet for at skabe forskudte pauser, som er fyldt til at danne signatur L1 indsættelse sekvenser (fx TTTTAA) kaldet target websted gentagelser (TSD) 9,10. Denne proces er kendt som target prime revers transskription (TPRT) og fører til insertipå af komplette eller trunkerede kopier af L1 / andre DNA&#39;er med TSDs i begge ender af den indsatte sekvens. L1 retrotransposition er også blevet vist at være formidlet gennem TPRT-lignende ikke-homolog endesammenbinding i nogle celletyper 11. L1 retrotransposition anvendte vektor i vores studier er ikke-episomale og består af mærkede L1 -ORF1 &amp; 2p drevet af kombinerede CMV-L1-5&#39;UTR promotorer (figur 1) 12. Tidligere versioner af denne konstruktion er blevet beskrevet i undersøgelser under anvendelse gær og humane cellekulturer 13,14,15. To forskellige CMV-promotorer lokaliseret ved 5 &#39;og 3&#39; enderne af vektoren, med 3&#39;-enden placeret i omvendt orientering til at drive ekspression af neomycin efter splejsning og integration. Den retrotransposition indikator kassetten ved 3&#39;-enden består af en neomycin gen indsat antisense til L1 -ORFs og gøres inaktive ved adskillelse i to halvdele ved en globi intron med splejset donor (SD) og splejset acceptor (SA) steder (Figur 1). På en integration i et kromosom, er L1 transkriberet fra den fælles promotor til frembringelse af en mRNA, som består af en bicistronisk mRNA og inaktive neomycin mRNA. Under RNA-bearbejdning, er globin intron splejset ud af neomycingenet at genskabe en fuldt funktionel neomycin-gen. Det hybride mRNA er pakket ind i en RNP i cis og translokeres ind i kernen, hvor den er integreret i genomet som enten fuld længde eller trunkerede indrykninger vha TPRT. Her beskriver vi en metode, der bruger fluorescens in situ hybridisering (FISH) med sonder specifikt rettet mod den splejsede neomycin gen (SNeo) at spore L1 -retrotransposiition mønstre og indsættelse satser på det indre kerne niveau. Effektiviteten og specificiteten af ​​detektion blev bekræftet ved hjælp retrotransposition kompetent og inkompetente konstruktioner og sonder til Detect SNeo eller neomycin og globin intron junction 16. Denne metode udgør nogle af manglerne ved cellekultur baseret retrotranspositionshastigheder analyser, såsom flere indsættelser, koloni modstand og gunstige klon ekspansion.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Labeling Probes</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Go Tag DNA polymerase</td>
			<td>Promega</td>
			<td>M3178</td>
			<td></td>
		</tr>
		<tr>
			<td>GO Tag 10X colorless buffer</td>
			<td>Promega</td>
			<td>M3178</td>
			<td></td>
		</tr>
		<tr>
			<td>Individual dNTP</td>
			<td>Sigma</td>
			<td>DNTP10</td>
			<td>Adjust the concentration of dATP, dGTP, dCTP to 2mM and dTTP to 1.5mM&#160; in nuclease free water.</td>
		</tr>
		<tr>
			<td>&#160;dUTP-16-Biotin (0.5mM)</td>
			<td>Roche</td>
			<td>11093070910</td>
			<td></td>
		</tr>
		<tr>
			<td>dUTP-FITC (0.5mM)</td>
			<td>Thermo Scientific</td>
			<td>R0101</td>
			<td></td>
		</tr>
		<tr>
			<td>dUTP-CY3 (0.5mM)</td>
			<td>Sigma</td>
			<td>GEPA53022</td>
			<td></td>
		</tr>
		<tr>
			<td>MIRUS FISH Labeling Kit</td>
			<td>MIRUS</td>
			<td>MIR3625</td>
			<td></td>
		</tr>
		<tr>
			<td>MIRUS FISH Labeling Kit</td>
			<td>MIRUS</td>
			<td>MIR3225</td>
			<td></td>
		</tr>
		<tr>
			<td>NucleoSpin PCR Clean-Up kit&#160;</td>
			<td>Qiagen</td>
			<td>1410/0030</td>
			<td>Any PCR clean reagent can be used in place of NucleoSpin PCR Clean Up Kit</td>
		</tr>
		<tr>
			<td>PCR Machine</td>
			<td></td>
			<td></td>
			<td>Any Thermocycler machine can be used to amplify the label product.</td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>Sigma</td>
			<td>A9539</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Preparing chromosome Spreads.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160;&#160; Colcemid&#160;</td>
			<td>Life Technologies&#160;</td>
			<td>15212-012</td>
			<td>Add Colcemid directly to growth media&#160; to a final concentration of 0.4 &#181;g/mL</td>
		</tr>
		<tr>
			<td>1M KCl</td>
			<td>Sigma</td>
			<td>P9541</td>
			<td>Dilute 1M KCl solution to 75 mM solution to make Hypotonic Solution</td>
		</tr>
		<tr>
			<td>Carnoy Fixative Solution</td>
			<td></td>
			<td></td>
			<td>Mix 3 volumes of methanol and 1 volume of acetic acid to make Carnoy Fixative Solution. Make Fresh everytime.</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma</td>
			<td>322415</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic acid</td>
			<td>Sigma</td>
			<td>320099</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst-33342</td>
			<td>Thermo Scientific</td>
			<td>62249</td>
			<td>Dissolve Hoechst-33342 in PBS to final concentration of 1 mg/mL.</td>
		</tr>
		<tr>
			<td>Diamond Point Marker</td>
			<td>Thermo Scientific</td>
			<td>750</td>
			<td></td>
		</tr>
		<tr>
			<td>Frosted Slides</td>
			<td>Thermo Scientific</td>
			<td>2951-001</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA (0.25%)</td>
			<td>Life Technologies&#160;</td>
			<td>R001100</td>
			<td>To detech cells, incubate cell in Trypsin for 5 mins and inactive with equal volume of complete media</td>
		</tr>
		<tr>
			<td>Cover slides&#160;</td>
			<td>VWR</td>
			<td>48366067</td>
			<td></td>
		</tr>
		<tr>
			<td>Coplin Jars</td>
			<td>Thermo Scientific</td>
			<td>107</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Heat Block</td>
			<td></td>
			<td></td>
			<td>Any heat block can be used for this purpose, though blocks fitted for heating slides are recommended.</td>
		</tr>
		<tr>
			<td>&#160;Beaker (600ml)</td>
			<td>Sigma</td>
			<td>CLS1003600</td>
			<td>Fill the beaker with water, heat to boil, use the hot steam to burst chromosomes.</td>
		</tr>
		<tr>
			<td>Nikon Microscope</td>
			<td>Nikon</td>
			<td>125690</td>
			<td>Any microscope can be used to look at spread quality.</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Reagents and Materials for FISH</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Trisodium citrate</td>
			<td>Sigma</td>
			<td>S1804</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chroride</td>
			<td>Sigma</td>
			<td>S3014</td>
			<td></td>
		</tr>
		<tr>
			<td>Formamide</td>
			<td>Sigma</td>
			<td>F9037</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween-20</td>
			<td>Sigma</td>
			<td>F1379</td>
			<td></td>
		</tr>
		<tr>
			<td>Detran Sulfate</td>
			<td>Sigma</td>
			<td>D8906</td>
			<td></td>
		</tr>
		<tr>
			<td>SDS</td>
			<td>Sigma</td>
			<td>L3771</td>
			<td></td>
		</tr>
		<tr>
			<td>Salmon Sperm DNA</td>
			<td>Life Technologies&#160;</td>
			<td>15632-011</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Sigma</td>
			<td>A8531</td>
			<td></td>
		</tr>
		<tr>
			<td>HCl (N)</td>
			<td>Sigma</td>
			<td>38283</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethyl Alcohol</td>
			<td>Sigma</td>
			<td>459844</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma</td>
			<td>322415</td>
			<td></td>
		</tr>
		<tr>
			<td>DPBS</td>
			<td>Life Technologies&#160;</td>
			<td>14190-250</td>
			<td></td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>Sigma</td>
			<td>S8045</td>
			<td></td>
		</tr>
		<tr>
			<td>Rnase A</td>
			<td>Sigma</td>
			<td>R4642</td>
			<td></td>
		</tr>
		<tr>
			<td>Pepsin</td>
			<td>Sigma</td>
			<td>P6887</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde (PFA)</td>
			<td>Sigma</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst-33342</td>
			<td>Thermo Scientific</td>
			<td>62249</td>
			<td>Dissolve Hoechst-33342 in PBS to final concentration of 1 mg/mL.</td>
		</tr>
		<tr>
			<td>Rubber Cement/Cytobond Sealant&#160;</td>
			<td></td>
			<td>2020-00-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Seven Coplin Jars</td>
			<td>Thermo Scientific</td>
			<td>107</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160; Dark Humidified chamber</td>
			<td>Sigma</td>
			<td>CLS2551</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover slides&#160;</td>
			<td>VWR</td>
			<td>48366067</td>
			<td></td>
		</tr>
		<tr>
			<td>Dry Digital Heat Block</td>
			<td>VWR</td>
			<td>13259</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Fluorescence Microscope</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>20X Saline-Sodium Citrate (20X SSC)</td>
			<td></td>
			<td></td>
			<td>Combine 175 g of NaCl, and 88.2 g of trisodium citrate with 800 mL of molecular grade H2O. Stir while adjusting to pH 7. Once the all salts dissolve, adjust the volume to 1 L and filter through 0.22 &#181;m Filter paper. Store at 4 &#176;C.</td>
		</tr>
		<tr>
			<td>&#160;1mg/mL of Rnase A</td>
			<td></td>
			<td></td>
			<td>Dilute 20X SSC buffer to 2X SSC buffer. Dissolve RNase A in 2X SSC buffer to a final concentration of 1 mg/mL. Make fresh solution every time.</td>
		</tr>
		<tr>
			<td>1% Pepsin</td>
			<td></td>
			<td></td>
			<td>Dissolve&#160; pepsin (W/V) in 10 mM HCl to a final concentration of 1 % solution. Make fresh every time.</td>
		</tr>
		<tr>
			<td>4% Paraformaldehyde (4% PFA)</td>
			<td></td>
			<td></td>
			<td>Weigh 4.0 g of PFA in fume hood, add 50 mL of 1xPBS, heat to 60 &#176;C while stirring and adjust the pH with drops of NaOH until all PFA dissolves and the solution becomes clear. Adjust the volume to 100 mL, filter through 0.22 &#181;m Filter paper and store 5 mL aliquots at -20 &#176;C. Thaw aliquot of PFA at 37 &#176;C for 10-15 min for subsequent uses.&#160; Adjust filter size depending on amount of paraformaldehyde.</td>
		</tr>
		<tr>
			<td>Wash Buffer</td>
			<td></td>
			<td></td>
			<td>Combine 100 mL of Formamide (20%) with 2.5 mL of 20X SSC, adjust to pH 7 with 1.0 M HCl and bring the volume to 500 mL with molecular grade H2O.</td>
		</tr>
		<tr>
			<td>Hybridization Buffer</td>
			<td></td>
			<td></td>
			<td>Combine 50% formamide, 10% dextran sulfate, 0.1% SDS, and 300 ng/mL Salmon Sperm DNA in 2X SSC buffer.&#160; Amount of Formamide determine how focused chromatids are, titrate the amount&#160;</td>
		</tr>
		<tr>
			<td>Detection Buffer</td>
			<td></td>
			<td></td>
			<td>Dilute 20X SSC buffer to 4X and add 0.2% Tween-20 to make detection buffer.</td>
		</tr>
		<tr>
			<td>Blocking Buffer</td>
			<td></td>
			<td></td>
			<td>Combine 5% bovine serum albumin (BSA) with 0.2% Tween-20 in 4X SSC buffer.</td>
		</tr>
		<tr>
			<td>Dehydrating Solution</td>
			<td></td>
			<td></td>
			<td>Make 70%, 80%, and 95% ethanol solutions.</td>
		</tr>
	</tbody>
</table>

analysis of line-1 retrotransposition at the single nucleus level

Long interspersed nuclear element-1 (Line-1 or L1) accounts for approximately 17% of the DNA present in the human genome. While the majority of L1s are inactive due to 5' truncations, ~80-100 of these elements remain retrotransposition competent and propagate to different locations throughout the genome via RNA intermediates. While older L1s are believed to target AT rich regions of the genome, the chromosomal targets of newer, more active L1s remain poorly defined. Here we describe fluorescence in situ hybridization (FISH) methodology that can be used to track patterns of L1 insertion and rates of ectopic L1 incorporation at the single nucleus level. In these experiments, fluorescein isothiocyanate/cyanine-3 (FITC/CY3) labeled neomycin probes were employed to track L1 retrotransposition in vitro in HepG2 cells stably expressing ectopic L1. This methodology prevents errors in the estimation of rates of retrotransposition posed by toxicity and account for the occurrence of multiple insertions into a single nucleus.

Et skematisk diagram af L1-retrotransposition vektoren er vist i figur 1. Vektoren består af et neomycin-gen i antisense-orientering til L1 ORF&#39;er der er afbrudt af en globin intron i sense-orientering og klemt sammen ved SD og SA sites. Når stabilt integreret i et kromosom, er L1 mRNA transkriberet fra den kombinerede CMV og L1-5&#39;UTR promotor (figur 1). Under RNA-bearbejdning, er globin intron splejset ud af neomycin...

Watch this Scientific Journal Video about Analysis of LINE-1 Retrotransposition at the Single Nucleus Level at JoVE.com

Analysis of LINE-1 Retrotransposition at the Single Nucleus Level

Analyse af LINE-1 retrotransposition på Single Nucleus Level

Her beskæftiger vi FISH metode til at spore LINE-1 retrotransposition på den enkelte kerner niveau kromosomspredninger af HepG2 cellelinjer stabilt udtrykker syntetisk LINE-1.

Long interspersed nuclear element-1 (Line-1 or L1) accounts for approximately 17% of the DNA present in the human genome. While the majority of L1s are ...

Research

JoVE Journal

Biology

Method for Measurement of Viral Fusion Kinetics at the Single Particle Level

Membrane fusion is an essential step during entry of enveloped viruses into cells. Conventional fusion assays typically report on a large number of fusion ...

Direct Analysis of Single Cells by Mass Spectrometry at Atmospheric Pressure

Analysis of biochemicals in single cells is important for understanding cell metabolism, cell cycle, adaptation, disease states, etc. Even the same cell ...

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations

Studere Proteolyse af cyclin B på enkelt celle niveau i hele cellepopulationer

Equal distribution of chromosomes between the two daughter cells during cell division is a prerequisite for guaranteeing genetic stability 1. Inaccuracies ...

Efficient Agroinfiltration of Plants for High-level Transient Expression of Recombinant Proteins

Effektiv Agroinfiltration af planter til højt niveau transient ekspression af rekombinante proteiner

Mammalian cell culture is the major platform for commercial production of human vaccines and therapeutic proteins. However, it cannot meet the increasing ...

Analysis of Global RNA Synthesis at the Single Cell Level following Hypoxia

Analyse af Global RNA-syntese på enkelt celle niveau efter Hypoxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a ...

CUBIC Protocol Visualizes Protein Expression at Single Cell Resolution in Whole Mount Skin Preparations

CUBIC protokol Visualiserer Protein Expression på Single Cell Opløsning i Whole Mount Skin Forberedelser

The skin is essential for our survival. The outer epidermal layer consists of the interfollicular epidermis, which is a stratified squamous epithelium ...

Analysis of Beta-cell Function Using Single-cell Resolution Calcium Imaging in Zebrafish Islets

Analyse af Beta-celle funktion ved hjælp af encellede opløsning Calcium Imaging i zebrafisk Holme

Pancreatic beta-cells respond to increasing blood glucose concentrations by secreting the hormone insulin. The dysfunction of beta-cells leads to ...

Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified &#955; DNA at the Single Molecule Level

Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified ÃƒÆ’Ã…Â½Ãƒâ€šÃ‚Â» DNA at the Single Molecule Level

Visualisere samspillet mellem Qdot-mærket Protein og Site-specifically modificeret λ DNA på enkelt-molekyle niveau

The fluorescence microscopy&#160;has made great contributions in dissecting the mechanisms of complex biological processes at the single molecule level. ...

Probing mRNA Kinetics in Space and Time in Escherichia coli using Two-Color Single-Molecule Fluorescence In Situ Hybridization

Probing mRNA Kinetics in Space and Time in Escherichia coli using Two-Color Single-Molecule Fluorescence In Situ Hybridization

Sondering mRNA kinetik i rum og tid i Escherichia coli ved hjælp af to-color single-molecule fluorescens In Situ Hybridization

Single-molecule fluorescence in situ hybridization (smFISH) allows for counting the absolute number of mRNAs in individual cells. Here, we describe an ...