Wir möchten unsere Wertschätzung für die Eingabe und Kommentare von Mitgliedern des Padilla Lab vermitteln. Nematode Stämme in dieser Arbeit wurden von der Caenorhabditis Genetics Center, das von der NIH National Center for Research Resources (NCRR) finanziert ist. Wir anerkennen und danken Dr. Lon Turnbull für technische Hilfe bei der konfokalen Mikroskopie. Diese Arbeit wurde durch ein Stipendium der National Science Foundation (NSF-IOS, CAREER) an PAP unterstützt

Ein. Probenvorbereitung <ol><li> Produzieren oder zu erhalten entsprechenden transgenen C. elegans-Stamm von Interesse unter Verwendung transgener Methoden oder von Caenorhabditis Genetics Stock Center (CGC) oder Kollegen. In diesem Fall sind wir mit dem Stamm TH32 (pie-1 :: tbg-1 :: GFP; pie-1 :: GFP :: H2B) 5 bis Chromosomen und Zentrosomen als Marker für die Zellteilung zu visualisieren. </li><li> Generieren Sie eine synchronisierte Bevölkerung mit einem der drei Methoden: 1) zerfallen gravid Erwachsenen in Hypochloritlösung und verwenden restlichen Embryonen 6, 2) holen gravid Erwachsenen auf eine gesetzte Platte und laß ihnen lag Embryonen für 1-2 Stunden, oder 3) Pick L4 Larven von einer gemischten Bevölkerung und Umzug in ein neues seeded Platte. </li><li> Wachsen Nematoden bei 20 ° C bis graviden jungen Erwachsenenalter, die in etwa 96 Stunden aus dem Schlüpfen dauert, 72 h von L1-Larven oder 24 h nach der Häutung L4. Embryonen (2-20 Zellen) in utero enthalten große Blastomeren und Kerne, die optimal für imag sindten sub-zellulären und sub-atomaren Veränderungen sind. Diese Methode bietet eine Möglichkeit, eine Bevölkerung von jungen Erwachsenen, die eine reichliche Anzahl von frühen Embryonen enthalten generieren. </li></ol> 2. Slide Vorbereitung und Anoxia Chamber Set Up <ol><li> Machen Sie eine feuchte Kammer, vorbereitete Folien, indem Sie ein feuchtes Papiertuch in einem großen Petrischale oder bin mit einem Deckel von ausreichender Größe bedeckt halten. </li><li> Planen geschmolzene 2% Agarose in entionisiertem H 2 O durch Erhitzen Mischung in Glaswaren über Mikrowelle oder Wasserbad. </li><li> Platz 1-3 Tropfen warmen Agarose auf einer sauberen Glasobjektträger. Sofort einen zweiten Schieber senkrecht auf der Agarose Drop (s) invertiert, leicht drücken, so dass die resultierende Pad dünn sein und frei von Luftblasen. </li><li> Nehmen Sie sich Zeit zu kühlen und langsam auseinander nehmen die beiden Objektträger Verlassen der Agarose Pad intakt auf einer der Folien. Es ist wichtig sicherzustellen, die Agarose-Pad ist dünn genug, um nicht Störe mit der Fähigkeit, das Mikroskop später konzentrieren. Fähigkeit zur Probe visualisieren ist auch abhängig von der spezifischen optischen Abstand des Objektivs im Gebrauch die zwischen Mikroskopen variieren kann. </li><li> Mit einem sauberen Rasierklinge eine Agarose-Pad in ein kleines Quadrat formen. Bewahren Sie in der vorbereiteten feuchten Kammer bis zum Gebrauch. </li><li> Sorgfältig unter Verwendung der gleichen sauberen Rasierklinge, nehmen die Kante der Agarose Pad und sie von der Folie auf eine runde 25 mm Mikro Abdeckglases, die Vermeidung der Ansammlung von Luftblasen unter dem Pad. Der runde Deckgläser gewählt zu bedienen passt entsprechend in der microincubator. </li><li> Einen Tropfen Anästhetikum (0,5% Tricain, 0,05% Tetramisol in M9-Puffer) auf die Agarose Pad zur Verwendung als Anästhetikum. Wählen 5-10 Würmer und Stelle in den Tropfen Anästhetikum. Lassen Sie 1-3 min für Würmer, um die Bewegung zu beenden. </li><li> Die Begründung für die Beobachtung Embryonen im Uterus erwachsenen, anstatt zerschnitten Embryonen, ist das Potenzial der Embryo desicca minimierention und Bewegung durch die Strömung von Stickstoffgas über den Embryo. </li><li> Sofort einen Tropfen Halocarbonöl auf der Würmer, die Würmer vor Austrocknung zu verhindern, wie Gas durch die Kammer durchströmt wird. Da die Halocarbonöl ist zähflüssig kann man wählen Sie eine Pipettenspitze oder der Spitze eines Wurms nutzen, um Öl-und Drop auf die Würmer zu sammeln. </li><li> Sobald der kreisförmigen Deckglas mit den Würmern wartet schlossen die beiden Hälften des Leiden Perfusion microincubator werden getrennt und die Deckgläser wird dann vorsichtig auf die aufrechte Bodenrings angeordnet. Die beiden Seiten der Kammer werden dann geschlossen fest zusammen. </li><li> Die Kammer wird dann mit dem Stickstoff Gastank über flexible Kunststoffschlauch verbunden und in die entsprechende Stelle auf dem Mikroskoptisch (Abbildung 1C). Zu diesem Zeitpunkt wird der Schlauch und microincubator sollte sorgfältig auf eventuelle Leckagen werden durch eine sichere Befestigung der Schläuche und der Anschluss-Stecker entlang der Seite der Kammer kontrolliert. Eines kann ALso leicht eine geringe Menge Seife Wasser über die Rohrleitung für Luftblasen, die sich bilden, wenn ein Leck vorhanden ist aussehen ausbreiten. </li></ol> 3. Mikroskopie in Anoxia <ol><li> Suchen Tieren bei niedriger Vergrößerung, dann in den entsprechenden höherer Vergrößerung (64x für diese Anwendung) zu Bild Gewebe oder Zellen von Interesse wie embryonale Blastomeren oder Oozyten bei Erwachsenen bewegen. Einschalten des Lasers, um 488 nm GFP-Signal anzuzeigen und zu lokalisieren GFP-Fusionsprotein in der Zelle (n) von Interesse. </li><li> Um der Verhaftung zu bestimmten Stadium des Zellzyklus visualisieren (zB späten Prophase) identifizieren Blastomeren in früheren Phasen der Zellteilung (zB verspätete Interphase oder frühen Prophase). Zellulären Marker wie Centriol Position Einleitung Chromosomenkondensation, Chromosom Lage und Vorhandensein oder Nichtvorhandensein der Kernhülle wird zur Ermittlung Zellzyklusstadium (Abbildung 2A). </li><li> Die Kammer wird dann mit Stickstoffgas (99,999% perfundiertN 2; &lt;2 ppm O 2). In diesem Fall haben wir einen Druck von 6 bar zu verwenden, jedoch Druck eventuell angepasst und optimiert werden je nach Größe der einzelnen microincubator und Durchmesser der Schlauch in Gebrauch ist. Weiterhin die Blastomere (en) als der Stickstoff füllt die Kammer, Einstellen der Brennebene nach Bedarf überwachen. </li><li> An diesem Punkt hat Zeitraffer-Aufnahmen begonnen. Abbildungssystem wird so lange wie notwendig durchgeführt, um interessierende Phänomen erfassen, in diesem Fall Prophase Verhaftung und Andocken von Chromosomen auf der inneren Kernmembran. Die Bilder werden einmal alle 10 sec nicht länger als 30 min genommen. Frequenzen der Bilderfassung und Einstellungen wie Gain und Laserleistung sollte nach Bedarf eingestellt werden. </li><li> Die Zeit, in welcher die Embryonen zu der anoxischen Umgebung reagieren kann je nach Zellzyklusstadium auf Anoxie Belichtung. Typischerweise Anoxie-induzierten Prophase Festnahme erfolgt innerhalb von 20-30 min zu beginnen Stickstoffgasstrom. Wir haben Anoxie-induzierten Zellzyklusarrest Berufs beobachtetrring in &lt;20 min. Bilder können in diesem Zeitraum erhalten werden, oder bestimmte Bilder können später von einem Zeitraffer-Serie werden. Eine weitere Option ist es, Video-Mikroskopie verwenden, um sub-zellulären Strukturen in Embryonen zu visualisieren. </li><li> Um eine Wiederherstellung aus der Anoxie-induzierten arretierten Zustand zu dokumentieren, wird das Gas abgeschaltet und die Kammer erlaubt ist, zu Normoxie durch Diffusion wieder während der Aufzeichnung eines Zeitraffer-Serie. Wiederaufnahme der Zellzyklusprogression und Undocking von Chromosomen tritt normalerweise innerhalb von 5-20 min Drehen des Stickstoffgases aus. </li><li> Beachten Sie, dass in getrennten Experimenten ein Indikator Anoxie, Resazurin, in der Durchflusskammer Mikrokammer platziert wurde, es wurde ermittelt, dass die Kammer anoxischen auf durchschnittlich ca. 19 min wird nach Stickstoffgasstrom wurde gestartet. </li><li> Bilder und Videos werden unter Verwendung Imaris, Image J oder Photoshop importiert und in QuickTime für die Anzeige. </li></ol>

<ol>
	<li>Powell-Coffman, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+signaling+and+resistance+in+C.+elegans.">Hypoxia signaling and resistance in C. elegans.</a> Trends Endocrinol. Metab. 21 (10), 435-440 (2010).</li><li>Padilla, P. A., Ladage, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suspended+animation,+diapause+and+quiescence:+Arresting+the+cell+cycle+in+C.+elegans.">Suspended animation, diapause and quiescence: Arresting the cell cycle in C. elegans.</a> Cell Cycle. 11, (2012).</li><li>Hu, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dauer.">Dauer.</a> WormBook. , 1-19 (2007).</li><li>Zhou, K. I., Pincus, Z., Slack, F. 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B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Nematode Caenorhabditis elegans. , 587-606 (1988).</li><li>Padilla, P. A., Nystul, T. G., Zager, R. A., Johnson, A. C., Roth, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dephosphorylation+of+Cell+Cycle-regulated+Proteins+Correlates+with+Anoxia-induced+Suspended+Animation+in+Caenorhabditis+elegans.">Dephosphorylation of Cell Cycle-regulated Proteins Correlates with Anoxia-induced Suspended Animation in Caenorhabditis elegans.</a> Mol. Biol Cell. 13, 1473-1483 (2002).</li><li>Hajeri, V. A., Trejo, J., Padilla, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+sub-nuclear+changes+in+Caenorhabditis+elegans+embryos+exposed+to+brief,+intermediate+and+long-term+anoxia+to+analyze+anoxia-induced+cell+cycle+arrest.">Characterization of sub-nuclear changes in Caenorhabditis elegans embryos exposed to brief, intermediate and long-term anoxia to analyze anoxia-induced cell cycle arrest.</a> BMC Cell Biol. 6, 1471-2121 (2005).</li><li>Padilla, P. A., Goy, J. M., Hajeri, P. A., Padilla, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Anoxia. , (2012).</li><li>Hajeri, V. A., Little, B. A., Ladage, M. L., Padilla, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NPP-16/Nup50+function+and+CDK-1+inactivation+are+associated+with+anoxia-induced+prophase+arrest+in+Caenorhabditis+elegans.">NPP-16/Nup50 function and CDK-1 inactivation are associated with anoxia-induced prophase arrest in Caenorhabditis elegans.</a> Mol. Biol. Cell. 21, 712-724 (2010).</li><li>Nystul, T. G., Goldmark, J. P., Padilla, P. A., Roth, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suspended+animation+in+C.+elegans+requires+the+spindle+checkpoint.">Suspended animation in C. elegans requires the spindle checkpoint.</a> Science. 302, 1038-1041 (2003).</li><li>Margalit, A., Vlcek, S., Gruenbaum, Y., Foisner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breaking+and+making+of+the+nuclear+envelope.">Breaking and making of the nuclear envelope.</a> J. Cell Biochem. 95, 454-465 (2005).</li><li>Maddox, A. S., Maddox, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+imaging+of+cellular+processes+in+Caenorhabditis+elegans.">High-resolution imaging of cellular processes in Caenorhabditis elegans.</a> Methods Cell Biol. 107, 1-34 (2012).</li><li>Miller, D. L., Roth, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=C.+elegans+are+protected+from+lethal+hypoxia+by+an+embryonic+diapause.">C. elegans are protected from lethal hypoxia by an embryonic diapause.</a> Curr. Biol. 19, 1233-1237 (2009).</li></ol>

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Sauerstoffmangel und Suspended Animation Obgleich das Engagement in schweren Sauerstoffmangel kann tödlich sein für einige Organismen, sind einige Organismen, um die Exposition gegenüber Anoxie überleben. Im Falle von C. elegans, hängt Überleben von Anoxie Belichtung auf Entwicklungsstadium und ist ansprechend auf Anoxie Eintritt in einen Zustand der reversiblen suspendiert Animation in dem eine Anzahl von beobachtbaren biologische Prozesse werden verhaftet. Zellteilung, Entwickl...

<table border="1"><tbody><tr><td> Reagenzien / Equipment </td><td></td><td></td><td> Zusammensetzung </td></tr><tr><td> Hypochloritlösung </td><td></td><td></td><td> 0,7 g KOH, 12 ml 5% NaOCl, um 50 ml zu bringen mit ddH 2 0 </td></tr><tr><td> M9-Puffer </td><td></td><td></td><td> 3 g KH 2 PO 4, 11 g Na 2 HPO 4, 5 g NaCl, 1 ml (1 M) MgSO 4 pro 1 L ddH 2 O </td></tr><tr><td> Glasobjektträger </td><td> Fisher Scientific </td><td> 12-550-343 </td><td> 3 &quot;x1&quot; x1.0 mm </td></tr><tr><td> Round micro Deckglas </td><td> Electron Microscopy Sciences </td><td> 72223-01 </td><td> 25 mm Durchmesser </td></tr><tr><td> Halocarbonöl 700 </td><td> Sigma </td><td> H8898-100ml </td><td></td></tr><tr><td> Narkose </td><td></td><td></td><td> 0,5% tricaine, 0,05% Tetramisol </td></tr><tr><td> Leiden Closed Perfusion Microincubator </td><td> Harvard Apparatus </td><td> 650041 </td><td></td></tr><tr><td> UHP Stickstoff </td><td> Calgaz (Air Liquide) </td><td></td><td> &gt; 99,9990% N 2 &lt;2 ppm O 2 </td></tr><tr><td> Kunststoffschlauch </td><td> VWR </td><td> 89068-468 </td><td> 0,062 &quot;ID x 0,125&quot; OD </td></tr><tr><td> Spinning-Disk-konfokale Mikroskop </td><td> McBain Systeme </td><td></td><td> Zeiss invertiert optischen Mikroskop, Epifluoreszenz Beleuchtungssystem, CSU-10 Yokogawa konfokalen Scanner, Hamamatsu-Elektronen-Vervielfacher CCD-Kamera. </td></tr></tbody></table>

use of time lapse microscopy to visualize anoxia-induced suspended animation in c. elegans embryos

Caenorhabdits elegans wurde ausgiebig in der Studie der Stressresistenz, die durch die Transparenz des adulten Stadien und Embryo als auch durch die Verfügbarkeit von genetischen Mutanten und transgenen Linien Expression einer Vielzahl von Fusionsproteinen 1-4 erleichtert wird. Darüber hinaus können dynamische Prozesse wie Zellteilung Darstellung unter Verwendung von fluoreszierend markierten Reporter-Proteine ​​werden. Das Studium der Mitose kann durch den Einsatz von Zeitrafferexperimente in verschiedenen Systemen einschließlich intakten Organismen erleichtert; somit der frühen C. elegans Embryo wird auch für diese Studie geeignet. Präsentiert hier ist eine Technik, mit der in vivo Bildgebung von sub-zellulären Strukturen in Reaktion auf Sauerstoffmangel (99,999% N 2; &lt;2 ppm O 2) Stress ist möglich, mit einem einfachen Gasfluss durch Setup auf einem High-Power-Mikroskop. Ein microincubation Kammer in Verbindung mit Stickstoffgas durchströmt und einer drehenden Scheibe konfokalen Mikroskop verwendetum eine kontrollierte Umgebung, in der Tiere in vivo abgebildet werden können. Verwendung GFP-markierten Gamma-Tubulin und Histon, kann die Dynamik und Verhaftung der Zellteilung kontrolliert werden, bevor, während und nach der Einwirkung von einer sauerstoffarmen Umgebung. Die Ergebnisse dieser Technik sind hochauflösende, detaillierte Videos und Bilder von zellulären Strukturen innerhalb Blastomeren von Embryonen ausgesetzt Sauerstoffmangel.

C. elegans Embryonen bei starken Sauerstoffmangel (Anoxie) können durch die Verhaftung biologische Prozesse einschließlich Entwicklung und Zellteilung 7 überleben. Die Anoxie induzierte Verhaftung der Zellteilung können überwacht werden, bei einem sub-zellulären Ebene durch Verwendung einer microincubation Kammer in Verbindung mit Stickstoffgas durchströmt und einer drehenden Scheibe konfokalen Mikroskops um eine kontrollierte Umgebung, in der Tiere in vivo abgebildet werden kann erst...

Watch this Scientific Journal Video about Use of Time Lapse Microscopy to Visualize Anoxia-induced Suspended Animation in C. elegans Embryos at JoVE.com

Use of Time Lapse Microscopy to Visualize Anoxia-induced Suspended Animation in C. elegans Embryos

Hier wird beschrieben ein<em&gt; In vivo</em&gt; Technik zur Bilder subzellulären Strukturen in Tieren, die mit Anoxie einen Gasstrom durch microincubation Kammer in Verbindung mit einer drehenden Scheibe Konfokalmikroskop. Dieses Verfahren ist einfach und flexibel genug, um eine Vielzahl von experimentellen Parameter und Modellsystemen anzupassen.

Verwendung von Zeitraffer-Mikroskopie zur Anoxie-induzierten Suspended Animation in Visualisieren<em&gt; C. elegans</em&gt; Embryonen

Caenorhabdits elegans has been used extensively in the study of stress resistance, which is facilitated by the transparency of the adult and embryo stages ...

use-time-lapse-microscopy-to-visualize-anoxia-induced-suspended

Research

JoVE Journal

Biology

Use of Time Lapse Microscopy to Visualize Anoxia-induced Suspended Animation in C. elegans Embryos

11.5K Aufrufe.  University of North Texas. Hier wird beschrieben ein In vivo Technik zur Bilder subzellulären Strukturen in Tieren, die mit Anoxie einen Gasstrom durch microincubation Kammer in Verbindung mit einer drehenden Scheibe Konfokalmikroskop. Dieses Verfahren ist einfach und flexibel genug, um eine Vielzahl von experimentellen Parameter und Modellsystemen anzupassen.

Serie: Use of Time Lapse Microscopy to Visualize Anoxia-induced Suspended Animation in C. elegans Embryos

Monitoring Actin Disassembly with Time-lapse Microscopy

Okay, so what I'd like to do today is to show you how to construct a flow chamber, a fusion chamber for imaging on an upright microscope. What then I then do is I create two spaces using film. So what I do is I take the para film, I cut it into small strips.Next I'm going to, this will basically form the channels for the, the walls, and I dry them with a tilted air. I put the cover slip on top of the para, And here's the finished. Then I heat it on a heat block to melt the param and basically create a seal.So what this is, is the, the cover glass here, and then on top of the cover glass is two layers of phim as you see right here. And then on top of this, again, there's a, it's a 22 by two two mil meter cover slip. This one right here, which I pressed against the param to fall the seal.Okay, so the liquid goes in in one direction here and I can suck it out with a filter paper here in this direction. And I'll show you how to do that in a bit. So what I like to do is I like to put it in a humidified chamber, which is very simple.Take two kind of elevated strips and have a filter of paper underneath. And to keep it noisy as I, I put the cover, cover slip on the flow chamber on. Now the way you introduce a solution to the chamber is that you just put the pipet tip at the entrance of the chamber and you just split.Now what I do is I incubate the chamber with the lid closed for 10 minutes. What I usually do to suck the liquid out from the other side is to use it, get a filter paper and cut it into thin strips like this. And I take one of these thin strips and I simultaneously apply the solution into the entrance while putting the filter paper at the exit to suck the exchange, the solution.So you'll see the liquid flowing through the solution. And then I wait for five minutes for the mid close. Now what I'm ready to do is to actually put that the actin it and the actin, I actually have to polymerize, I polymerize inside the flow chamber and it's just the same procedures before.So because like this, and then now that the action is polymerized, I wash out all the un excess un polymerized action using a large volume of just buffer. So here I have about a hundred microliters and it's a few reaction chamber volumes worth of buffer. Just, you know, when the filter paper becomes saturated, I have to change the direction.Okay?And so I'm ready to do imaging with this. So perfusion chamber with actin attached to it. Now I take the slide, mount it under the microscope, and since I'm imaging with an oil objective, I'm gonna put some immersion oil on the top surface of the cover, grass touch, such so assess solution or protein or anything on acting inside.So what I do is I can actually exchange the solution side while I'm doing the time lapse imaging. As such.

Überwachung Aktin Demontage mit Zeitraffer-Mikroskopie

Forschung

Biologie

Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual branches of peripheral sensory axons in zebrafish using the focused power of a femtosecond laser mounted on a two-photon microscope. The parameters for successful two-photon axotomy must be optimized for each microscope. We will demonstrate two-photon axotomy on both a custom built two-photon microscope and a Zeiss 510 confocal/two-photon to provide two examples.

Zebrafish trigeminal sensory neurons can be visualized in a transgenic line expressing GFP driven by a sensory neuron specific promoter 1. We have adapted this zebrafish trigeminal model to directly observe sensory axon regeneration in living zebrafish embryos. Embryos are anesthetized with tricaine and positioned within a drop of agarose as it solidifies. Immobilized embryos are sealed within an imaging chamber filled with phenylthiourea (PTU) Ringers. We have found that embryos can be continuously imaged in these chambers for 12-48 hours. A single confocal image is then captured to determine the desired site of axotomy. The region of interest is located on the two-photon microscope by imaging the sensory axons under low, non-damaging power. After zooming in on the desired site of axotomy, the power is increased and a single scan of that defined region is sufficient to sever the axon. Multiple location time-lapse imaging is then set up on a confocal microscope to directly observe axonal recovery from injury.

Here we describe a method for mounting zebrafish embryos for long-term imaging, two-photon imaging and tissue-damage techniques, and time-lapse confocal imaging.

Zwei-Photonen-Axotomie und Zeitraffer-konfokale Bildgebung in lebenden Zebrafisch-Embryonen

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo.  ...

Time-lapse Imaging of Mitosis After siRNA Transfection

Changes in cellular organization and chromosome dynamics that occur during mitosis are tightly coordinated to ensure accurate inheritance of genomic and cellular content. Hallmark events of mitosis, such as chromosome movement, can be readily tracked on an individual cell basis using time-lapse fluorescence microscopy of mammalian cell lines expressing specific GFP-tagged proteins. In combination with RNAi-based depletion, this can be a powerful method for pinpointing the stage(s) of mitosis where defects occur after levels of a particular protein have been lowered. In this protocol, we present a basic method for assessing the effect of depleting a potential mitotic regulatory protein on the timing of mitosis. Cells are transfected with siRNA, placed in a stage-top incubation chamber, and imaged using an automated fluorescence microscope. We describe how to use software to set up a time-lapse experiment, how to process the image sequences to make either still-image montages or movies, and how to quantify and analyze the timing of mitotic stages using a cell-line expressing mCherry-tagged histone H2B. Finally, we discuss important considerations for designing a time-lapse experiment. This strategy is complementary to other approaches and offers the advantages of 1) sensitivity to changes in kinetics that might not be observed when looking at cells as a population and 2) analysis of mitosis without the need to synchronize the cell cycle using drug treatments. The visual information from such imaging experiments not only allows the sub-stages of mitosis to be assessed, but can also provide unexpected insight that would not be apparent from cell cycle analysis by FACS.

Here we describe a basic protocol to image and quantify the mitotic timing of live mammalian tissue culture cells after siRNA transfection.

Zeitraffer-Imaging der Mitose Nach siRNA-Transfektion

Changes in cellular organization and chromosome dynamics that occur during mitosis are tightly coordinated to ensure accurate inheritance of genomic and ...

Imaging C. elegans Embryos using an Epifluorescent Microscope and Open Source Software

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using fluorescent-labeled reporter proteins or differential interference contrast (DIC) microscopy, allows for the examination of the temporal progression of these dynamic events which is otherwise inferred from analysis of fixed samples1,2. Moreover, the study of the developmental regulations of cellular processes necessitates conducting time-lapse experiments on an intact organism during development. The Caenorhabiditis elegans embryo is light-transparent and has a rapid, invariant developmental program with a known cell lineage3, thus providing an ideal experiment model for studying questions in cell biology4,5and development6-9. C. elegans is amendable to genetic manipulation by forward genetics (based on random mutagenesis10,11) and reverse genetics to target specific genes (based on RNAi-mediated interference and targeted mutagenesis12-15). In addition, transgenic animals can be readily created to express fluorescently tagged proteins or reporters16,17. These traits combine to make it easy to identify the genetic pathways regulating fundamental cellular and developmental processes in vivo18-21. In this protocol we present methods for live imaging of C. elegans embryos using DIC optics or GFP fluorescence on a compound epifluorescent microscope. We demonstrate the ease with which readily available microscopes, typically used for fixed sample imaging, can also be applied for time-lapse analysis using open-source software to automate the imaging process.

Imaging C. elegans Embryos using an Epifluorescent Microscope and Open Source Software

The C. elegans embryo is a powerful system for studying cell biology and development. We present a protocol for live imaging of C. elegans embryos utilizing DIC optics or fluorescence using readily available epifluorescent microscopes and open-source software.

Imaging C. elegans Embryos mit einem Epifluoreszenz-Mikroskop und Open Source Software

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using ...

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

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, messages are carried by neurotransmitters released from presynaptic terminals and received by receptors on postsynaptic cells. Our previous research in Caenorhabditis elegans has shown that VSM-1 negatively regulates exocytosis. Additionally, analysis of synapses in vsm-1 mutants showed that animals lacking a fully functional VSM-1 have increased synaptic connectivity. Based on these preliminary findings, we hypothesized that C. elegans VSM-1 may play a crucial role in synaptogenesis. To test this hypothesis, double-labeled microarray analysis was performed, and gene expression profiles were determined. First, total RNA was isolated, reversely transcribed to cDNA, and hybridized to the DNA microarrays. Then, in-silico analysis of fluorescent probe hybridization revealed significant induction of many genes coding for members of the major sperm protein family (MSP) in mutants with enhanced synaptogenesis. MSPs are the major component of sperm in C. elegans and appear to signal nematode oocyte maturation and ovulation . In fruit flies, Chai and colleagues 1 demonstrated that MSP-like molecules regulate presynaptic bouton number and size at the neuromuscular junction. Moreover, analysis performed by Tsuda and coworkers 2 suggested that MSPs may act as ligands for Eph receptors and trigger receptor tyrosine kinase signaling cascades. Lastly, real time PCR analysis corroborated that the gene coding for MSP-32 is induced in vsm-1(ok1468) mutants. Taken together, research performed by our laboratory has shown that vsm-1 mutants have a significant increase in synaptic density, which could be mediated by MSP-32 signaling.

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

Microarray analysis was conducted to determine genetic expression profiles in C. elegans, and real-time PCR was used to validate and quantify microarray data.

Bestimmung genetischer Expressionsprofile in C. elegans Verwenden Microarray-und Real-time PCR

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, ...

Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

Caenorhabditis elegans has often been used as a model system in studies of early developmental processes. The transparency of the 
embryos, the genetic resources, and the relative ease of transformation are qualities that make C. elegans an excellent model for early embryogenesis. Laser-based 
confocal microscopy and fluorescently labeled tags allow researchers to follow specific cellular structures and proteins in the developing embryo. For example, 
one can follow specific organelles, such as lysosomes or mitochondria, using fluorescently labeled dyes. These dyes can be delivered to the early embryo by means 
of microinjection into the adult gonad. Also, the localization of specific proteins can be followed using fluorescent protein tags. Examples are presented here 
demonstrating the use of a fluorescent lysosomal dye as well as fluorescently tagged histone and ubiquitin proteins. The labeled histone is used to visualize 
the DNA and thus identify the stage of the cell cycle. GFP-tagged ubiquitin reveals the dynamics of ubiquitinated vesicles in the early embryo. Observations 
of labeled lysosomes and GFP:: ubiquitin can be used to determine if there is colocalization between ubiquitinated vesicles and lysosomes. A technique for 
the microinjection of the lysosomal dye is presented. Techniques for generating transgenenic strains are presented elsewhere (1, 2). For imaging, embryos 
are cut out of adult hermaphrodite nematodes and mounted onto 2% agarose pads followed by time-lapse microscopy on a standard laser scanning confocal 
microscope or a spinning disk confocal microscope. This methodology provides for the high resolution visualization of early embryogenesis.

Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

This article describes a technique for the visualization of the early events of embryogenesis in the nematode Caenorhabditis elegans.

Zeitraffer-Mikroskopie der frühen Embryogenese in Caenorhabditis elegans

Caenorhabditis elegans has often been used as a model system in studies of early developmental processes.  The transparency of the 
embryos, the genetic ...

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways1. More sophisticated tools and resources for studies in this system are facilitating continued discovery of genes with more subtle phenotypes or roles. 
Here we present a generalized protocol we adapted for identifying C. elegans genes with postembryonic phenotypes of interest using RNAi2. This procedure is easily modified to assay the phenotype of choice, whether by light or fluorescence optics on a dissecting or compound microscope. This screening protocol capitalizes on the physical assets of the organism and molecular tools the C. elegans research community has produced. As an example, we demonstrate the use of an integrated transgene that expresses a fluorescent product in an RNAi screen to identify genes required for the normal localization of this product in late stage larvae and adults. First, we used a commercially available genomic RNAi library with full-length cDNA inserts. This library facilitates the rapid identification of multiple candidates by RNAi reduction of the candidate gene product. Second, we generated an integrated transgene that expresses our fluorecently tagged protein of interest in an RNAi-sensitive background. Third, by exposing hatched animals to RNAi, this screen permits identification of gene products that have a vital embryonic role that would otherwise mask a post-embryonic role in regulating the protein of interest. Lastly, this screen uses a compound microscope equipped for single cell resolution.

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

We describe a sensitized method to identify postembryonic regulators of protein expression and localization in C. elegans using an RNAi-based genomic screen and an integrated transgene that expresses a functional, fluorescently tagged protein.

RNAi-Screening auf postembryonalen Phänotypen in Identifizieren C elegans</em

C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways1. More sophisticated ...

Quantitative Analysis of Random Migration of Cells Using Time-lapse Video Microscopy

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During directional migration, cells move rapidly in response to an extracellular chemotactic signal, or in response to intrinsic cues 3 provided by the basic motility machinery. Random migration occurs when a cell possesses low intrinsic directionality, allowing the cells to explore their local environment.
Cell migration is a complex process, in the initial response cell undergoes polarization and extends protrusions in the direction of migration 2. Traditional methods to measure migration such as the Boyden chamber migration assay is an easy method to measure chemotaxis in vitro, which allows measuring migration as an end point result. However, this approach neither allows measurement of individual migration parameters, nor does it allow to visualization of morphological changes that cell undergoes during migration.
Here, we present a method that allows us to monitor migrating cells in real time using video - time lapse microscopy. Since cell migration and invasion are hallmarks of cancer, this method will be applicable in studying cancer cell migration and invasion in vitro. Random migration of platelets has been considered as one of the parameters of platelet function 4, hence this method could also be helpful in studying platelet functions. This assay has the advantage of being rapid, reliable, reproducible, and does not require optimization of cell numbers. In order to maintain physiologically suitable conditions for cells, the microscope is equipped with CO2 supply and temperature thermostat. Cell movement is monitored by taking pictures using a camera fitted to the microscope at regular intervals. Cell migration can be calculated by measuring average speed and average displacement, which is calculated by Slidebook software.

This method allows monitoring of cells in real time and quantitative measurements of different cell migration parameters such as speed, displacement, and velocity. Unlike the traditional methods, this real time approach is not based on endpoint quantitative migration measurements; instead it allows monitoring and calculating different parameters continuously.

Quantitative Analyse der ungerichtete Migration von Zellen unter Verwendung Zeitraffer-Video-Mikroskopie

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During ...

Visualization of Craniofacial Development in the sox10: kaede Transgenic Zebrafish Line Using Time-lapse Confocal Microscopy

Vertebrate palatogenesis is a highly choreographed and complex developmental process, which involves migration of cranial neural crest (CNC) cells, convergence and extension of facial prominences, and maturation of the craniofacial skeleton. To study the contribution of the cranial neural crest to specific regions of the zebrafish palate a sox10: kaede transgenic zebrafish line was generated. Sox10 provides lineage restriction of the kaede reporter protein to the neural crest, thereby making the cell labeling a more precise process than traditional dye or reporter mRNA injection. Kaede is a photo-convertible protein that turns from green to red after photo activation and makes it possible to follow cells precisely. The sox10: kaede transgenic line was used to perform lineage analysis to delineate CNC cell populations that give rise to maxillary versus mandibular elements and illustrate homology of facial prominences to amniotes. This protocol describes the steps to generate a live time-lapse video of a sox10: kaede zebrafish embryo. Development of the ethmoid plate will serve as a practical example. This protocol can be applied to making a time-lapse confocal recording of any kaede or similar photoconvertible reporter protein in transgenic zebrafish. Furthermore, it can be used to capture not only normal, but also abnormal development of craniofacial structures in the zebrafish mutants.

Visualization of experimental data has become a key element in presenting results to the scientific community. Generation of live time-lapse recording of growing embryos contributes to better presentation and understanding of complex developmental processes. This protocol is a step-by-step guide to cell labeling via photoconversion of kaede protein in zebrafish.

Visualisierung von Craniofacial Entwicklung in den sox10: kaede transgener Zebrafische Zeile mit Zeitraffer-konfokale Mikroskopie

Vertebrate palatogenesis is a highly choreographed and complex developmental process, which involves migration of cranial neural crest (CNC) cells, ...

Methods to Assess Subcellular Compartments of Muscle in C. elegans

Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age are significant public health burdens. We currently understand little about the genetic regulation of muscle health with disease or age. The nematode C. elegans is an established model for understanding the genomic regulation of biological processes of interest. This worm&#8217;s body wall muscles display a large degree of homology with the muscles of higher metazoan species. Since C. elegans is a transparent organism, the localization of GFP to mitochondria and sarcomeres allows visualization of these structures in vivo. Similarly, feeding animals cationic dyes, which accumulate based on the existence of a mitochondrial membrane potential, allows the assessment of mitochondrial function in vivo. These methods, as well as assessment of muscle protein homeostasis, are combined with assessment of whole animal muscle function, in the form of movement assays, to allow correlation of sub-cellular defects with functional measures of muscle performance. Thus, C. elegans provides a powerful platform with which to assess the impact of mutations, gene knockdown, and/or chemical compounds upon muscle structure and function. Lastly, as GFP, cationic dyes, and movement assays are assessed non-invasively, prospective studies of muscle structure and function can be conducted across the whole life course and this at present cannot be easily investigated in vivo in any other organism.

Methods to Assess Subcellular Compartments of Muscle in C. elegans

Skeletal muscle is essential for locomotion and is the bodies&#8217; main protein store. Muscle health measurements within C. elegans are described. Prospective changes to muscle structure and function are assessed using localized GFP and cationic dyes.

Methoden zur subzellulärer Kompartimente der Muskel in Beurteilen<em&gt; C. elegans</em

Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age ...