Wir danken Ihnen, Kevin Miyashiro für die Beschichtung und Pflege von Zellkulturen, Dr. Terri Schochet für die Bereitstellung von Zellkulturen für die Bilder in diesem Dokument enthalten. Darüber hinaus Dankeschön an Kevin Miyashiro, Dr. Peter Buckley, und Tiina Pertiz für die Eingabe über die aRNA Verfahren. Die Finanzierung dieser Arbeit wurde vom National Institute on Aging, National Institute on Mental Health und der Human Resources Fact Finder Mitteln aus dem Commonwealth of Pennsylvania.

<ol>
	<li>Davis, J. E., Eberwine, J. H., Hinkle, D. A., Marciano, P. G., Meaney, D. F., McIntonsh, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methodological+considerations+regarding+single-cell+gene+expression+profiling+for+brain+injury.">Methodological considerations regarding single-cell gene expression profiling for brain injury.</a> Neurochemical Research. 29, 1113-1121 (2004).</li><li>Eberwine, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+molecular+biology.">Single-cell molecular biology.</a> Nature Neuroscience. 4, 1155-1156 (2001).</li><li>Kamme, F., Salunga, R., Yu, J., Tran, D., Zhu, J., Luo, J., Bittner, A., Guo, H., Miller, N., Wan, J., Erlander, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+microarray+analysis+in+hippocampus+CA1:+Demonstration+and+Validation+of+Cellular+Heterogeneity.">Single-cell microarray analysis in hippocampus CA1: Demonstration and Validation of Cellular Heterogeneity.</a> The Journal of Neuroscience. 23, 3607-3607 (2003).</li><li>Hinkle, D., Glanzer, J., Sarabi, A., Pajunen, T., Zielinski, J., Belt, B., Miyashiro, K., McIntosh, T., Eberwine, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+neurons+as+experimental+systems+in+molecular+biology.">Single neurons as experimental systems in molecular biology.</a> Progress in Neurobiology. 72, 129-142 (2004).</li><li>Ginsberg, S. D., Elarova, I., Ruben, M., Tan, F., Counts, S. E., Eberwine, J. H., Trojanowski, J. Q., Hemby, S. E., Mufson, E. J., Che, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+gene+expression+analysis:+Implications+for+Neurodegenerative+and+Neuropsychiatric+Disorders.">Single-cell gene expression analysis: Implications for Neurodegenerative and Neuropsychiatric Disorders.</a> Neeurochemical Research. 29, 1053-1064 (2004).</li><li>Eberwine, J., Spencer, K., Miyashirto, K., Mackler, S., Finnell, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complementary+DNA+synthesis+in+situ:+methods+and+applications.">Complementary DNA synthesis in situ: methods and applications.</a> Methods Enxymol. 216, 80-100 (1992).</li><li>Eberwine, J., Yeh, H., Miyashiro, K., Cao, Y., Nair, S., Finnell, R., Zettel, M., Coleman, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+gene+expression+in+single+live+neurons.">Analysis of gene expression in single live neurons.</a> Proc. Natl. Acad. Sci. USA. 89, 3010-3014 (1992).</li><li>Kelz, M. B., Dent, G. W., Therianos, S., Marciano, P. G., McIntosh, T. K., Coleman, P. D., Eberwine, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+antisense+RNA+amplification+and+microarray+analysis+as+a+tool+for+studying+neurological+degeneration+and+restoration.">Single-cell antisense RNA amplification and microarray analysis as a tool for studying neurological degeneration and restoration.</a> Sci. Aging Knowledge Eviron. 1, re1-re1 (2002).</li><li>Banker, G. A., Cowan, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+hippocampal+neurons+in+dispersed+cell+culture.">Rat hippocampal neurons in dispersed cell culture.</a> Brain Research. 126, 397-425 (1977).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> P-1000 &#38; P-97 Pipette Cookbook. , (2010).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> MinElute Handbook For MinElute Reaction Cleanup Kit. , 28-29 (2004).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Megascript kit. , 7-8 .</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> MEGAclear kit. , 4-5 .</li><li>Eberwine, J., Kacharmina, J. E., Andrews, C., Miyashiro, K., McIntosh, T., Becker, K., Barrett, T., Hinkle, D., Dent, G., Marciano, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mRNA+expression+analysis+of+tissue+sections+and+single+cells.">mRNA expression analysis of tissue sections and single cells.</a> The Journal of Neuroscience. 21, 8310-8314 (2001).</li><li>Van Gelder, R. N., von Zastrow, M. E., Yool, A., Dement, W. C., Barchas, J. D., Eberwine, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amplified+RNA+synthesized+from+limited+quantities+of+heterogeneous+cDNA.">Amplified RNA synthesized from limited quantities of heterogeneous cDNA.</a> Proc. Natl. Acad. Sci. USA. 87, 1663-1667 (1990).</li><li>Miyashiro, K., Dichter, M., Eberwine, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+nature+and+differential+distribution+of+mRNAs+in+hippocampal+neuritis:+Implications+for+neuronal+functioning.">On the nature and differential distribution of mRNAs in hippocampal neuritis: Implications for neuronal functioning.</a> Proc. Natl. Acad. Sci. USA. 91, 10800-10804 (1994).</li><li>Sul, J., Wo, C. K., Zeng, F., Jochems, J., Lee, M. T., Kim, T. K., Peritz, T., Buckley, P., Cappelleri, D. J., Maronski, M., Kim, M., Kumar, V., Meaney, D., Kim, J., Eberwine, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptional+transfer+produces+a+predictable+cellular+phenotype.">Transcriptional transfer produces a predictable cellular phenotype.</a> Proc. Natl. Acad. Sci. USA. 106, 7624-7629 (2009).</li><li>Sow, F. B., Gallup, J. M., Sacco, R. E., Ackerman, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+capture+microdissection+revisited+as+a+tool+for+transcriptomic+analysis:+Application+of+an+excel-based+qPCR+preparation+software+(PREXCEL-Q).">Laser capture microdissection revisited as a tool for transcriptomic analysis: Application of an excel-based qPCR preparation software (PREXCEL-Q).</a> Int. J. Biomed. Sci. 5, (2010).</li><li>Vandewoestyne, M., Deforce, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+capture+microdissection+in+forensic+research:+a+review.">Laser capture microdissection in forensic research: a review.</a> Int J Legal Med. 124, (2010).</li><li>Eberwine, J., Bartfai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+cell+transcriptomics+of+hypothalamic+warm+sensitive+neurons+that+control+core+body+temperature+and+fever+response+Signaling+asymmetry+and+an+extension+of+chemical+neuroanatomy.">Single cell transcriptomics of hypothalamic warm sensitive neurons that control core body temperature and fever response Signaling asymmetry and an extension of chemical neuroanatomy.</a> Pharmacol. Ther. , (2010).</li></ol>

Dr. Eberwine ist ein Erfinder auf dem aRNA Patent, das LBS-Technologien, in denen Dr. Eberwine ist ein Aktionär lizenziert wurde.

Hinweise und Problembehandlung <ul><li> Sie können vor und nach Bildern, die zeigen, dass die Zielzelle isoliert wurde und dass die verbleibenden Penumbra wurde unberührt gelassen zu nehmen. </li><li> Wenn zu viel Lösung geht in die Pipette, wie Sie ernten, können Sie 3-Wege-Luer-Lock Armaturen und den Kolben der Spritze bis Überdruck in der Leitung zu halten. Die gewünschte Lautstärke wird mit der Art der Verarbeitung variieren, aber bis zu 5 ul sollte für die meisten Anwendungen gut. </li></ul> Allgemeine Tipps molekularbiologischen Techniken <ul><li> Vortex alle Lager Rohre und Spin sie nieder, bevor es zu einer Reaktion. NEVER Wirbel Enzyme. </li><li> Gründlich mischen Reaktionen vor Zugabe des Enzyms, um sicherzustellen, dass der Puffer in der richtigen Konzentration ist. </li><li> Keep Enzym Aktien bei -20 ° C, wenn möglich mit einem stratacooler. Ansonsten, direkt vor dem Gebrauch zu entfernen, halten Sie auf dem Eis, und kehren sofort auf -20 ° C. </li><li> Achten Sie immer Mastermixen bei der Vorbereitung mehr als eine Reaktion auf Pipettieren Fehler zu reduzieren. Berechnen Sie das erforderliche Volumen auf Basis der Anzahl der Proben und fügen 10-20%. </li><li> Shop-RNA bei -80 ° C zu verzögern Abbau. RNA ist sehr stabil gelagert in einem Puffer zu verzögern apurination von RNA, die in sauren Bedingungen auftritt. </li></ul> Grundzüge des aRNA Procedure Abbildung 4A zeigt die erste Runde der aRNA Verfahren. In den ersten Strang Reaktion, wählt der Poly-T Teil des T7-Oligo (dT) Primer für mRNA-Spezies (lange weiße Rechteck) durch Bindung an die polyA Schwanz. Einige microRNAs sind auch polyadenyliert und wird durch dieses Verfahren erfasst werden. Vor allem aber wird die am häufigsten vorkommende RNAs in der Zelle, ribosomale RNAs, nicht. Diese Oligo dient als Primer für Reverse Transkriptase mit einem komplementären Strang der cDNA (langes graues Rechteck) zu synthetisieren mit der mRNA als Vorlage. Die T7 Teil des T7-Oligo (dT)-Primer enthält die T7-RNA-Polymerase-Promotor in Frame mit der Sequenz antisense an den Start mRNA. Dies wird später in der in vitro Transkriptions-Reaktion eingesetzt. Anschließend wird die mRNA in die mRNA / DNA-Hybrid in den vorangegangenen Schritt erstellt teilhydrolysierte durch RNase H schaffen RNA &quot;Primer&quot; (kleine weiße Rechtecke) ähnlich wie die Okazaki-Fragmente in den rückständigen DNA-Synthese erstellt. DNA-Polymerase I benutzt die RNA-Fragmente prime DNA-Synthese mit dem DNA komplementär zur mRNA als Vorlage. Wenn es das nächste RNA-Fragment, dessen 5 erreicht &#39;nach 3&#39; Nuklease-Aktivität entfernt die Ribonukleotiden und ersetzt sie durch Desoxyribonukleotiden. DNA-Ligase zugesetzt wird, um alle Stränge, wo der Austausch der führenden Stranges ist nicht vollständig unterbinden. T4-DNA-Polymerase hinzugefügt wird, um in den Bereichen zu füllen, wo RNA-Fragmente als erste Primer für die DNA-Polymerase I zu schaffen diente eine blunt-ended doppelsträngigen cDNA, die dann vor der Durchführung des IVT Reaktion gereinigt. In der IVT Reaktion bindet T7-RNA-Polymerase, die T7-Promotors in der doppelsträngigen cDNA synthetisiert und Antisense-RNA-Moleküle (lange schwarze Rechtecke) mit der Sense-Strang als Vorlage aufgenommen. Dies dient als Verstärkung Schritt, in dem Tausende von Antisense-RNA-Moleküle aus jedem doppelsträngigen cDNA-Moleküls (Abbildung 4A) hergestellt werden. Die zweite Runde, wie in Abbildung 4B dargestellt, beginnt mit einem Reverse-Transkriptase-Reaktion, die ein wenig anders als in der ersten Runde, da die Ausgangs-RNA ist antisense (durchgezogene schwarze Rechteck) und es fehlt die polyadenyliert Schwanz, der von der T7-oligo gezielte wurde (dT)-Primer in der ersten Runde. Daher ist diese Reaktion mit Random-Primern (kleine graue Rechtecke) und die RNA anschließend denaturiert grundiert. Der zweite Strang Reaktion wird dann durch die T7-Oligo (dT)-Primer, die den Poly-A-Sequenz bindet an das 3&#39;-Ende des Sense-RNA in den vorangegangenen Reaktion der reversen Transkription erstellt grundiert. Ein weiterer IVT Reaktion ist in der gleichen Weise wie in der ersten Runde durchgeführt. Diese zweite Runde ist in der Regel mindestens einmal auf drei Runden der Amplifikation aus einer einzigen Zelle zu erreichen wiederholt. Anwendungen Die Techniken, die wir in diesem Artikel vorgestellt haben, können in eine Vielzahl von Anwendungen übersetzt werden. Die Einzelzellisolierung Protokoll kann für den Einsatz in akuten Schnitten geändert werden. 14 Obwohl technisch anspruchsvoll, die gleichen Prinzipien in dieser alternativen Zubereitung gelten. Außerdem, wenn die Größe der Pipette leicht angepasst ist, kann Aufnahmen der Physiologie der Zellen vor der Ernte was eine gut kontrollierte Untersuchung der molekularen Mechanismen hinter physiologischen Ausgänge erfolgen. Eine weitere kleine Änderung ist es, Prozesse aus der Zelle soma isolieren. 15 Für diese Anwendung zu sammeln Zellkörper mit einer Pipette und dann wieder mit einer frischen Pipette und sammeln 100-300 identifiziert dendrites oder Axonen pro Sammelrohr. 16 Sobald Zellen wurden geerntet, Vergleiche von mRNA Abundanzen und Kompositionen zwischen verschiedenen und sogar innerhalb der gleichen Zellpopulationen vorgenommen werden können. Die Einbeziehung biotinylierten-UTP in die dritte Runde aRNA ermöglicht Microarray-Analyse, um diese relative mRNA Häufigkeiten zu bestimmen. Die Zusammensetzung des ursprünglichen mRNA-Population kann auch nach dem aRNA Verfahren unter Verwendung der nächsten Generation Sequenzierung bestimmt werden. Das verstärkte aRNA kann auch verwendet werden, um Zellphänotyp Umwandlung Studien, in denen eine ganze Reihe von mRNAs aus einem Zelltyp in einen anderen Zelltyp transfiziert werden, um den Übergang von der Phänotyp des letzteren Zelltyp, in dem der ehemalige induzieren zu bestätigen, ein Verfahren, durch das Labor entwickelt und bekannt als Tiper. 17 Diese Studien sind besonders nützlich für die Untersuchung Krankheitsstadien und Zellphänotypen und solche Studien sind derzeit in den Labors. RT-PCR oder qPCR können auf das verstärkte Material durchgeführt werden, um die Expression von Zell-spezifische Gene zu bestätigen. Zusätzlich können Auswertungen der Effizienz der Transfektion oder Transduktion in der einzelnen Zelle Ebene getroffen werden. Vorteile und Einschränkungen Wie in der abstrakten gesagt, eliminiert Isolierung einzelner Zellen für die Analyse der Mittelung Effekte mit der Analyse von heterogenen Zellpopulationen zu sehen. Diese Mittelung Effekte falsch mRNA Häufigkeiten innerhalb einer einzigen Zelle, die durch über-repräsentiert reichlich Transkripte und Mittelung und die Verhinderung Detektion von vielen Low-Fülle-Transkripte. Die Durchflusszytometrie kann verwendet werden, um einzelne Zellen zu sortieren, aber diese Methode erfordert die Kenntnis der Zell-spezifische Marker und teure Ausrüstung. 18 Laser Mikrodissektion entweder mit UV-oder IR-Laser Mikrodissektion Systeme erlauben einzelne Zelle und sogar subzelluläre erfassen, erfordert aber Zellen von Interesse zu an der Oberfläche sehr dünne Schnitte entfernt werden. 19 Ähnliche um Durchflusszytometrie, Laser-Mikrodissektion auch teure Ausrüstung erforderlich. Einer der wichtigsten Vorteile der Elektrode basiert Sammlung oben beschriebene Technik ist, dass wertvolle elektrophysiologische Daten können aus der Zelle von Interesse vor der Ernte erzielt werden, so dass für Funktions-und Transkriptom-Analyse auf der gleichen Zelle durchgeführt werden. 20 A Kehrseite unserer Technik ist dass es erfordert Erfahrung im Umgang mit Mikromanipulatoren. Die Ermittler kennen Mikromanipulatoren finden diese Technik sehr intuitiv, aber Personen, die keine solche Erfahrung benötigen, um sich mit den feinen Bewegungen erforderlich. Inherent in jedem Verstärkung Technik ist die bevorzugte Verstärkung bestimmter Transkripte nach Größe und Nukleotid-Zusammensetzung. 4,6,7 Polymerase-Kettenreaktion (PCR) Techniken wie Reverse-Transkriptase-Polymerase-Kettenreaktion (RT-PCR) und Rapid Amplifikation von cDNA Enden (RACE) resultieren in exponentiellen Amplifikation der Transkripte, während die aRNA Verstärkung Vorgehen führt in lineare Verstärkung. So liegt einer der großen Vorteile der aRNA Verfahren in seiner Fähigkeit, besser zu bewahren die relativen Häufigkeiten der mRNA-Transkripte von nur linear verstärken etwaige Fehler oder Verzerrungen, die in der Verstärkung auftreten als exponentiell verstärkt gegen diesen Fehlern und Verzerrungen. Die aRNA Verfahren mit Microarray-Analyse gekoppelt ermöglicht einen Vergleich der mRNA Abundanzen zwischen einzelnen Zellen mit gleicher oder unterschiedlicher Morphologie, behandelt oder unbehandelt. Darüber hinaus können verstärkt Material für die Sequenzierung der nächsten Generation eingereicht werden. 5,8 Aber Vorsicht ist bei solchen Analysen, da im Gegensatz zu der Verwendung von Random-Primer für das Verfahren, die Oligo-dT grundiert Verfahren über Vorurteile Verstärkung der beschriebenen genommen werden 3 &#39;Enden der mRNA und führt in der Regel leichte Verkürzung der anschließenden verstärkt Material mit jeder Runde. Es sollte bei der Analyse von Microarray-Ergebnisse mit Standard-Methoden, da einige falsche abwesenden Anrufe aus leicht gekürzt amplifizierten Materials entstehen können übernommen werden. Darüber hinaus, während die Sequenzierung Ergebnisse werden in der Tat bieten die volle 5 &#39;Sequenz die meisten der ursprünglichen mRNA, die 5&#39; können Sequenzen von einigen mRNA entgehen lassen. Aus diesen Gründen sollte die Anzahl der Runden Verstärkungen begrenzt werden.

A correction was made to <a href="http://http://www.jove.com/video/2634/transcriptome-analysis-of-single-cells">Transcriptome Analysis of Single Cells</a>. There were errors in the volumes used in the aRNA Amplification section.

Erratum: Transcriptome Analysis of Single Cells

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Spiegelgas coverslips</td>
<td>&nbsp;</td>
<td>Carolina Biological</td>
<td>63-3029</td>
<td>&nbsp;</td>
<tr>
<td>Nunc 35x10 mm culture dishes</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>12-565-90</td>
<td>&nbsp;</td>
<tr>
<td>Water for cell culture</td>
<td>&nbsp;</td>
<td>Lonza</td>
<td>17-724Q</td>
<td>For making solutions used for cell culture and rinsing coverslips</td>
</tr>
<tr>
<td>Poly-D-Lysine MW70-150K</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>6407</td>
<td>&nbsp;</td>
<tr>
<td>Laminin, ultrapure</td>
<td>&nbsp;</td>
<td>BD Bioscience</td>
<td>354239</td>
<td>&nbsp;</td>
<tr>
<td>Boric acid</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>B0252</td>
<td>&nbsp;</td>
<tr>
<td>MEM with Earle&#x2019;s salts and glutamax</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>41090-101</td>
<td>For plating cells</td>
</tr>
<tr>
<td>D-glucose</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>G8769</td>
<td>&nbsp;</td>
<tr>
<td>Penicillin-streptomycin</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>15140-122</td>
<td>&nbsp;</td>
<tr>
<td>Horse serum</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>16050</td>
<td>&nbsp;</td>
<tr>
<td>Cytosine beta-D-arabinofuranoside</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>C1768</td>
<td>&nbsp;</td>
<tr>
<td>MEM with Earle&#x2019;s salts and L-glutamine</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>11095-098</td>
<td>For growing cells</td>
</tr>
<tr>
<td>Sodium pyruvate</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>P2256</td>
<td>&nbsp;</td>
<tr>
<td>B27 serum-free supplement</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>17504-044</td>
<td>&nbsp;</td>
<tr>
<td>Borosilicate glass capillary tubes (1.5mm O.D, 100mm length)</td>
<td>&nbsp;</td>
<td>Kimble Chase</td>
<td>34500 99</td>
<td>Any borosilicate glass pipette will work as long as the proper bore size is attained. </td>
</tr>
<tr>
<td>HBSS</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>14175</td>
<td>Any solution will work as long as the components won&#x2019;t interfere with any future processing (i.e. no Ca2+ or Mg2+)</td>
</tr>
<tr>
<td>1ml syringe</td>
<td>&nbsp;</td>
<td>BD</td>
<td>309628</td>
<td>&nbsp;</td>
<tr>
<td>Needle</td>
<td>&nbsp;</td>
<td>BD</td>
<td>&nbsp;</td>
<td>Gauge depends on the diameter of the pipettes</td>
</tr>
<tr>
<td>dNTP mix</td>
<td>&nbsp;</td>
<td>Amersham</td>
<td>28-4065-51</td>
<td>&nbsp;</td>
<tr>
<td>dt-T7 oligo</td>
<td>&nbsp;</td>
<td>Custom</td>
<td>Midland Certified</td>
<td>&nbsp;</td>
<tr>
<td>Second strand buffer (5x)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>Y01129</td>
<td>&nbsp;</td>
<tr>
<td>DTT</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Supplied with second strand buffer</td>
</tr>
<tr>
<td>E.coli DNA Ligase</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>100002324</td>
<td>&nbsp;</td>
<tr>
<td>DNA polymerase I</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>100004926</td>
<td>&nbsp;</td>
<tr>
<td>Rnase H</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>18021-071</td>
<td>&nbsp;</td>
<tr>
<td>Megascript T7 kit</td>
<td>&nbsp;</td>
<td>Ambion</td>
<td>AM1334</td>
<td>&nbsp;</td>
<tr>
<td>Random primers</td>
<td>&nbsp;</td>
<td>BMB</td>
<td>11034731001</td>
<td>&nbsp;</td>
<tr>
<td>Superscript III Reverse Transcriptase</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>56575</td>
<td>in kit (18080-044) comes with first strand buffer (Y02321) and DTT</td>
</tr>
<tr>
<td>MEGAclear Kit</td>
<td>&nbsp;</td>
<td>Ambion</td>
<td>1908</td>
<td>&nbsp;</td>
<tr>
<td>MinElute Reaction Cleanup Kit</td>
<td>&nbsp;</td>
<td>Qiagen</td>
<td>28206</td>
<td>&nbsp;</td>
<tr>
<td>T4 DNA polymerase</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>100004994</td>
<td>&nbsp;</td>
<tr>
<td>Rnasin</td>
<td>&nbsp;</td>
<td>Promega</td>
<td>N251B</td>
<td>&nbsp;</td>
<tr>
<td>Illumina TotalPrep RNA Amplification Kit</td>
<td>&nbsp;</td>
<td>Ambion</td>
<td>AMIL1791</td>
<td>&nbsp;</td>
<tr>
<td>Flaming/Brown micropipette puller</td>
<td>&nbsp;</td>
<td>Sutter Instruments</td>
<td>P-87</td>
<td>Sutter has many other models, many are discussed in the cookbook</td>
</tr>
<tr>
<td>Micromanipulator</td>
<td>&nbsp;</td>
<td>Olympus</td>
<td>&nbsp;</td>
<td>Many other micromanipulators will work such as the newer Eppendorf models</td>
</tr>
<tr>
<td>Pipette Holder</td>
<td>&nbsp;</td>
<td>Warner Instruments</td>
<td>MP-S15A</td>
<td>Will vary with micromanipulator and pipette O.D.</td>
</tr>
<tr>
<td>Bioanalyzer RNA 6000 Nano Kit</td>
<td>&nbsp;</td>
<td>Agilent</td>
<td>5067-1511</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

transcriptome analysis of single cells

Viele Genexpressionsanalyse Techniken beruhen auf Material aus heterogenen Populationen von Zellen aus dem Gewebe-Homogenate oder Zellen in Kultur isoliert. 1,2,3 Im Fall des Gehirns, Regionen wie der Hippocampus eine komplexe Anordnung von verschiedenen Zelltypen enthalten, die jeweils mit verschiedene mRNA-Profilen. Die Möglichkeit, einzelne Zellen Ernte ermöglicht eine genauere Untersuchung der molekularen Unterschiede zwischen und innerhalb von Zellpopulationen. Wir beschreiben eine einfache und schnelle Methode zur Ernte-Zellen für die weitere Verarbeitung. Pipetten oft in Elektrophysiologie werden eingesetzt, um zu isolieren (mit Aspiration) eine Zelle von Interesse und bequem hinterlegen sie in ein Eppendorf-Röhrchen für die weitere Verarbeitung mit einer beliebigen Anzahl von Techniken der Molekularbiologie. Unser Protokoll kann für die Ernte von Dendriten aus Zellkultur oder sogar einzelne Zellen aus akuten Scheiben geändert werden. Wir beschreiben auch die aRNA Amplifikationsmethode als wichtiger nachgeschalteten Anwendung der einzelnen Zelle Isolierungen. Diese Methode wurde zuvor von unserem Labor als Alternative zu anderen Genexpressionsanalyse Techniken wie Reverse-Transkriptase-oder real-time Polymerase-Kettenreaktion (PCR) entwickelt. 4,5,6,7,8 Diese Technik sorgt für lineare Verstärkung des polyadenyliert RNA Anfang mit nur Femtogramm des Materials und die daraus resultierende in Mikrogramm-Mengen von Antisense-RNA. Die linear verstärkte Material bietet eine genauere Schätzung als PCR exponentielle Vermehrung der relativen Häufigkeit von Komponenten der Transkriptom der isolierten Zellen. Das grundsätzliche Vorgehen besteht aus zwei Runden Verstärkung. Kurz gesagt, ist ein T7-RNA-Polymerase-Promotor site in doppelsträngigen cDNA aus der mRNA-Transkripte erstellt eingearbeitet. Eine Übernachtung in vitro-Transkription (IVT) Reaktion wird dann durchgeführt, in dem T7-RNA-Polymerase produziert viele Antisense-Transkripte von der doppelsträngigen cDNA. Die zweite Runde wiederholt diesen Vorgang aber einige technische Unterschiede, da das Ausgangsmaterial Antisense-RNA. Es ist Standard in die zweite Runde zu wiederholen, was in drei Runden der Amplifikation. Oft ist die dritte Runde in vitro Transkriptions-Reaktion unter Verwendung von biotinylierten Nucleosidtriphosphate, so dass die Antisense-RNA hergestellt hybridisiert werden können und erkannt auf einem Mikroarray. 7,8

Watch this Scientific Journal Video about Transcriptome Analysis of Single Cells at JoVE.com

Transcriptome Analysis of Single Cells

In diesem Artikel beschreiben wir eine einfache Methode für die Gewinnung von Einzelzellen aus der Ratte primären neuronalen Kulturen und anschließende Transkriptom-Analyse mit aRNA Verstärkung. Dieser Ansatz ist verallgemeinerbar zu jedem Zelltyp.

Transkriptom-Analyse von Einzelzellen

Many gene expression analysis techniques rely on material isolated from heterogeneous populations of cells from tissue homogenates or cells in ...

Research

JoVE Journal

Neuroscience

29.6K Aufrufe.  University of Pennsylvania. In diesem Artikel beschreiben wir eine einfache Methode für die Gewinnung von Einzelzellen aus der Ratte primären neuronalen Kulturen und anschließende Transkriptom-Analyse mit aRNA Verstärkung. Dieser Ansatz ist verallgemeinerbar zu jedem Zelltyp.

Serie: Transcriptome Analysis of Single Cells

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding fundamental biological mechanisms. Striking progress has been particularly evident in Drosophila, whose extensive toolkit of mutants and transgenic lines provides a convenient model to study evolutionarily-conserved developmental and cell biological mechanisms. We are interested in understanding the mechanisms that control cell fate specification in the adult peripheral nervous system (PNS) in Drosophila. Bristles that cover the head, thorax, abdomen, legs and wings of the adult fly are individual mechanosensory organs, and have been studied as a model system for understanding mechanisms of Notch-dependent cell fate decisions. Sensory organ precursor (SOP) cells of the microchaetes (or small bristles), are distributed throughout the epithelium of the pupal thorax, and are specified during the first 12 hours after the onset of pupariation. After specification, the SOP cells begin to divide, segregating the cell fate determinant Numb to one daughter cell during mitosis. Numb functions as a cell-autonomous inhibitor of the Notch signaling pathway.
Here, we show a method to follow protein dynamics in SOP cell and its progeny within the intact pupal thorax using a combination of tissue-specific Gal4 drivers and GFP-tagged fusion proteins 1,2.This technique has the advantage over fixed tissue or cultured explants because it allows us to follow the entire development of an organ from specification of the neural precursor to growth and terminal differentiation of the organ. We can therefore directly correlate changes in cell behavior to changes in terminal differentiation. Moreover, we can combine the live imaging technique with mosaic analysis with a repressible cell marker (MARCM) system to assess the dynamics of tagged proteins in mitotic SOPs under mutant or wildtype conditions. Using this technique, we and others have revealed novel insights into regulation of asymmetric cell division and the control of Notch signaling activation in SOP cells (examples include references 1-6,7 ,8).

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae

Live-Cell-Imaging von Sinnesorgan Vorläuferzellen im Intact Drosophila Puppen

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding ...

Forschung

Neurowissenschaften

Sequential Photo-bleaching to Delineate Single Schwann Cells at the Neuromuscular Junction

Sequential photo-bleaching provides a non-invasive way to label individual SCs at the NMJ. The NMJ is the largest synapse of the mammalian nervous system and has served as guiding model to study synaptic structure and function. In mouse NMJs motor axon terminals form pretzel-like contact sites with muscle fibers. The motor axon and its terminal are sheathed by SCs. Over the past decades, several transgenic mice have been generated to visualize motor neurons and SCs, for example Thy1-XFP1 and Plp-GFP mice2, respectively.
Along motor axons, myelinating axonal SCs are arranged in non-overlapping internodes, separated by nodes of Ranvier, to enable saltatory action potential propagation. In contrast, terminal SCs at the synapse are specialized glial cells, which monitor and promote neurotransmission, digest debris and guide regenerating axons. NMJs are tightly covered by up to half a dozen non-myelinating terminal SCs - these, however, cannot be individually resolved by light microscopy, as they are in direct membrane contact3.
Several approaches exist to individually visualize terminal SCs. None of these are flawless, though. For instance, dye filling, where single cells are impaled with a dye-filled microelectrode, requires destroying a labelled cell before filling a second one. This is not compatible with subsequent time-lapse recordings3. Multi-spectral "Brainbow" labeling of SCs has been achieved by using combinatorial expression of fluorescent proteins4. However, this technique requires combining several transgenes and is limited by the expression pattern of the promoters used. In the future, expression of "photo-switchable" proteins in SCs might be yet another alternative5. Here we present sequential photo-bleaching, where single cells are bleached, and their image obtained by subtraction. We believe that this approach - due to its ease and versatility - represents a lasting addition to the neuroscientist's technology palette, especially as it can be used in vivo and transferred to others cell types, anatomical sites or species6.
In the following protocol, we detail the application of sequential bleaching and subsequent confocal time-lapse microscopy to terminal SCs in triangularis sterni muscle explants. This thin, superficial and easily dissected nerve-muscle preparation7,8 has proven useful for studies of NMJ development, physiology and pathology9. Finally, we explain how the triangularis sterni muscle is prepared after fixation to perform correlated high-resolution confocal imaging, immunohistochemistry or ultrastructural examinations.

Visualizing individual cells in densely packed tissues, such as terminal Schwann cells (SCs) at neuromuscular junctions (NMJs), is challenging. "Sequential photo-bleaching" allows delineating single terminal SCs, for instance in the triangularis sterni muscle explant, a convenient nerve-muscle preparation, where sequential bleaching can be combined with time-lapse imaging and post-hoc immunostainings.

Sequential Photo-Bleiche zur Einzel-Schwann-Zellen an der neuromuskulären Synapse Delineate

Sequential photo-bleaching provides a non-invasive way to label individual SCs at the NMJ. The NMJ is the largest synapse of the mammalian nervous system ...

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

In this article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the lipophilic fluorescent membrane marker DiI. This method allows the visualization of neuronal cell morphology in great detail. It is possible to label any cell in the CNS: cell bodies of target neurons are visualized under DIC optics or by expression of a fluorescent genetic marker such as GFP. After labeling, the DiI can be transformed into a permanent brown stain by photoconversion to allow visualization of cell morphology with transmitted light and DIC optics. Alternatively, the DiI-labeled cells can be observed directly with confocal microscopy, enabling genetically introduced fluorescent reporter proteins to be colocalised. The technique can be used in any animal, irrespective of genotype, making it possible to analyze mutant phenotypes at single cell resolution.

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.

Beschriften einzelner Zellen im zentralen Nervensystem<em&gt; Drosophila melanogaster</em

In this  article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the ...

Laser Capture Microdissection of Enriched Populations of Neurons or Single Neurons for Gene Expression Analysis After Traumatic Brain Injury

Long-term cognitive disability after TBI is associated with injury-induced neurodegeneration in the hippocampus-a region in the medial temporal lobe that is critical for learning, memory and executive function.1,2 Hence our studies focus on gene expression analysis of specific neuronal populations in distinct subregions of the hippocampus. The technique of laser capture microdissection (LCM), introduced in 1996 by Emmert-Buck, et al.,3 has allowed for significant advances in gene expression analysis of single cells and enriched populations of cells from heterogeneous tissues such as the mammalian brain that contains thousands of functional cell types.4 We use LCM and a well established rat model of traumatic brain injury (TBI) to investigate the molecular mechanisms that underlie the pathogenesis of TBI. Following fluid-percussion TBI, brains are removed at pre-determined times post-injury, immediately frozen on dry ice, and prepared for sectioning in a cryostat. The rat brains can be embedded in OCT and sectioned immediately, or stored several months at -80 &deg;C before sectioning for laser capture microdissection. Additionally, we use LCM to study the effects of TBI on circadian rhythms. For this, we capture neurons from the suprachiasmatic nuclei that contain the master clock of the mammalian brain. Here, we demonstrate the use of LCM to obtain single identified neurons (injured and degenerating, Fluoro-Jade-positive, or uninjured, Fluoro-Jade-negative) and enriched populations of hippocampal neurons for subsequent gene expression analysis by real time PCR and/or whole-genome microarrays. These LCM-enabled studies have revealed that the selective vulnerability of anatomically distinct regions of the rat hippocampus are reflected in the different gene expression profiles of different populations of neurons obtained by LCM from these distinct regions. The results from our single-cell studies, where we compare the transcriptional profiles of dying and adjacent surviving hippocampal neurons, suggest the existence of a cell survival rheostat that regulates cell death and survival after TBI.

We describe how to use laser capture microdissection (LCM) to obtain enriched populations of hippocampal neurons or single neurons from frozen sections of the injured rat brain for subsequent gene expression analysis using quantitative real time PCR and/or whole-genome microarrays.

Laser Capture Mikrodissektion von Angereichert Populationen von Neuronen oder Single Neurons zur Genexpressionsanalyse Nach Traumatic Brain Injury

Long-term cognitive disability after TBI is associated with injury-induced neurodegeneration in the hippocampus-a region in the medial temporal lobe that ...

Peering at Brain Polysomes with Atomic Force Microscopy

The translational machinery, i.e., the polysome or polyribosome, is one of the biggest and most complex cytoplasmic machineries in cells. Polysomes, formed by ribosomes, mRNAs, several proteins and non-coding RNAs, represent integrated platforms where translational controls take place. However, while the ribosome has been widely studied, the organization of polysomes is still lacking comprehensive understanding. Thus much effort is required in order to elucidate polysome organization and any novel mechanism of translational control that may be embedded. Atomic force microscopy (AFM) is a type of scanning probe microscopy that allows the acquisition of 3D images at nanoscale resolution. Compared to electron microscopy (EM) techniques, one of the main advantages of AFM is that it can acquire thousands of images both in air and in solution, enabling the sample to be maintained under near physiological conditions without any need for staining and fixing procedures. Here, a detailed protocol for the accurate purification of polysomes from mouse brain and their deposition on mica substrates is described. This protocol enables polysome imaging in air and liquid with AFM and their reconstruction as three-dimensional objects. Complementary to cryo-electron microscopy (cryo-EM), the proposed method can be conveniently used for systematically analyzing polysomes and studying their organization.

While ribosome structure has been extensively characterized, the organization of polysomes is still understudied. To overcome this lack of knowledge, we present here a detailed preparation protocol for accurate imaging of mammalian polysomes by atomic force microscopy (AFM) in air and liquid.

Peering am Gehirn Polysomen mit Rasterkraftmikroskopie

The translational machinery, i.e., the polysome or polyribosome, is one of the biggest and most complex cytoplasmic machineries in cells. Polysomes, ...

Single-cell RNA-Seq of Defined Subsets of Retinal Ganglion Cells

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for the improved understanding of neuronal diversity, it is important to identify genes whose expression defines various subpopulations of cells. The retina serves as an excellent model for the study of central nervous system diversity, as it is composed of multiple major cell types. The study of each major class of cells has yielded genetic markers that facilitate the identification of these populations. However, multiple subtypes of cells exist within each of these major retinal cell classes, and few of these subtypes have known genetic markers, although many have been characterized by morphology or function. A knowledge of genetic markers for individual retinal subtypes would allow for the study and mapping of brain targets related to specific visual functions and may also lend insight into the gene networks that maintain cellular diversity. Current avenues used to identify the genetic markers of subtypes possess drawbacks, such as the classification of cell types following sequencing. This presents a challenge for data analysis and requires rigorous validation methods to ensure that clusters contain cells of the same function. We propose a technique for identifying the morphology and functionality of a cell prior to isolation and sequencing, which will allow for the easier identification of subtype-specific markers. This technique may be extended to non-neuronal cell types, as well as to rare populations of cells with minor variations. This protocol yields excellent-quality data, as many of the libraries have provided read depths greater than 20 million reads for single cells. This methodology overcomes many of the hurdles presented by Single-cell RNA-Seq and may be suitable for researchers aiming to profile cell types in a straightforward and highly efficient manner.

Here, we present a combinatorial approach for classifying neuronal cell types prior to isolation and for the subsequent characterization of single-cell transcriptomes. This protocol optimizes the preparation of samples for successful RNA Sequencing (RNA-Seq) and describes a methodology designed specifically for the enhanced understanding of cellular diversity.

Einzelzell-RNA-Seq von definierten Subsets von Retinal-Ganglion-Zellen

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for ...

Analysis of Immune Cells in Single Sciatic Nerves and Dorsal Root Ganglion from a Single Mouse Using Flow Cytometry

Nerve-resident immune cells in the peripheral nervous system (PNS) are essential to maintaining neuronal integrity in a healthy nerve. The immune cells of the PNS are affected by injury and disease, affecting the nerve function and the capacity for regeneration. Neuronal immune cells are commonly analyzed by immunofluorescence (IF). While IF is essential for determining the location of the immune cells in the nerve, IF is only semi-quantitative and the method is limited to the number of markers that can be analyzed simultaneously and the degree of surface expression. In this study, flow cytometry was used for quantitative analysis of leukocyte infiltration into sciatic nerves or dorsal root ganglions (DRGs) of individual mice. Single cell analysis was performed using DAPI and several proteins were analyzed simultaneously for either surface or intracellular expression. Both sciatic nerves from one mouse that were treated according to this protocol generated &#8805; 30,000 single nucleated events. The proportion of leukocytes in the sciatic nerves, determined by expression of CD45, was approximately 5% of total cell content in the sciatic nerve and approximately 5-10% in the DRG. Although this protocol focuses primarily on the immune cell population within the PNS, the flexibility of flow cytometry to measure a number of markers simultaneously means that the other cells populations present within the nerve, such as Schwann cells, pericytes, fibroblasts, and endothelial cells, can also be analyzed using this method. This method therefore provides a new means for studying systemic effects on the PNS, such as neurotoxicology and genetic models of neuropathy or in chronic diseases, such as diabetes.

Quantitative analysis of cell content within the murine sciatic nerve is difficult due to the scarcity of the tissue. This protocol describes a method for tissue digestion and preparation that provides sufficient cells for flow cytometry analysis of immune cell populations from nerves of individual mice.

Analyse von Immunzellen in einzelnen Ischias Nerven und Dorsal Root Ganglion aus einem einzigen Mausklick mit Durchflusszytometrie

Nerve-resident immune cells in the peripheral nervous system (PNS) are essential to maintaining neuronal integrity in a healthy nerve. The immune cells of ...

Isolation of Adult Spinal Cord Nuclei for Massively Parallel Single-nucleus RNA Sequencing

Probing an individual cell&#39;s gene expression enables the identification of cell type and cell state. Single-cell RNA sequencing has emerged as a powerful tool for studying transcriptional profiles of cells, particularly in heterogeneous tissues such as the central nervous system. However, dissociation methods required for single cell sequencing can lead to experimental changes in the gene expression and cell death. Furthermore, these methods are generally restricted to fresh tissue, thus limiting studies on archival and bio-bank material. Single nucleus RNA sequencing (snRNA-Seq) is an appealing alternative for transcriptional studies, given that it accurately identifies cell types, permits the study of tissue that is frozen or difficult to dissociate, and reduces dissociation-induced transcription. Here, we present a high-throughput protocol for rapid isolation of nuclei for downstream snRNA-Seq. This method enables isolation of nuclei from fresh or frozen spinal cord samples and can be combined with two massively parallel droplet encapsulation platforms.

Here, we present a protocol to rapidly isolate high-quality nuclei from the fresh or frozen tissue for downstream massively parallel RNA sequencing. We include detergent-mechanical and hypotonic-mechanical tissue disruption and cell lysis options, both of which can be used for isolation of nuclei.

Isolierung von Erwachsenen Rückenmark Kerne für massiv parallele Single-Kern-RNA-Sequenzierung

Probing an individual cell&#39;s gene expression enables the identification of cell type and cell state. Single-cell RNA sequencing has emerged as a ...

Analysis of Spliceosomal snRNA Localization in Human Hela Cells Using Microinjection

Biogenesis of spliceosomal snRNAs is a complex process involving both nuclear and cytoplasmic phases and the last step occurs in a nuclear compartment called the Cajal body. However, sequences that direct snRNA localization into this subnuclear structure have not been known until recently. To determine sequences important for accumulation of snRNAs in Cajal bodies, we employed microinjection of fluorescently labelled snRNAs followed by their localization inside cells. First, we prepared snRNA deletion mutants, synthesized DNA templates for in vitro transcription and transcribed snRNAs in the presence of UTP coupled with Alexa488. Labelled snRNAs were mixed with 70 kDa-Dextran conjugated with TRITC, and microinjected to the nucleus or the cytoplasm of human HeLa cells. Cells were incubated for 1 h and fixed and the Cajal body marker coilin was visualized by indirect immunofluorescence, while snRNAs and dextran, which serves as a marker of nuclear or cytoplasmic injection, were observed directly using a fluorescence microscope. This method allows for efficient and rapid testing of how various sequences influence RNA localization inside cells. Here, we show the importance of the Sm-binding sequence for efficient localization of snRNAs into the Cajal body.

Biogenesis of spliceosomal snRNAs is a complex process involving various cellular compartments. Here, we employed microinjection of fluorescently labelled snRNAs in order to monitor their transport inside the cell.

Analyse der Spliceosomalen snRNA-Lokalisierung in menschlichen Hela-Zellen mit Mikroinjektion

Biogenesis of spliceosomal snRNAs is a complex process involving both nuclear and cytoplasmic phases and the last step occurs in a nuclear compartment ...

A Scalable Model to Study the Effects of Blunt-Force Injury in Adult Zebrafish

Blunt-force traumatic brain injuries (TBI) are the most common form of head trauma, which spans a range of severities and results in complex and heterogenous secondary effects. While there is no mechanism to replace or regenerate the lost neurons following a TBI in humans, zebrafish possess the ability to regenerate neurons throughout their body, including the brain. To examine the breadth of pathologies exhibited in zebrafish following a blunt-force TBI and to study the mechanisms underlying the subsequent neuronal regenerative response, we modified the commonly used rodent Marmarou weight drop for the use in adult zebrafish. Our simple blunt-force TBI model is scalable, inducing a mild, moderate, or severe TBI, and recapitulates many of the phenotypes observed following human TBI, such as contact- and post-traumatic seizures, edema, subdural and intracerebral hematomas, and cognitive impairments, each displayed in an injury severity-dependent manner. TBI sequelae, which begin to appear within minutes of the injury, subside and return to near undamaged control levels within 7 days post-injury. The regenerative process begins as early as 48 hours post-injury (hpi), with the peak cell proliferation observed by 60 hpi. Thus, our zebrafish blunt-force TBI model produces characteristic primary and secondary injury TBI pathologies similar to human TBI, which allows for investigating disease onset and progression, along with the mechanisms of neuronal regeneration that is unique to zebrafish.

We modified the Marmarou weight drop model for adult zebrafish to examine a breadth of pathologies following blunt-force traumatic brain injury (TBI) and the mechanisms underlying subsequent neuronal regeneration. This blunt-force TBI model is scalable, induces a mild, moderate, or severe TBI, and recapitulates injury heterogeneity observed in human TBI.