CQS receives a fellowship from the LOEWE Excellence Cluster for Integrative Fungal Research (IPF). The author would like to thank Ida J. van der Klei for the P. chrysogenum strains used in this work and Andreas S. Reichert for the gift of rapamycin.

1. Herstellung von P. chrysogenum für die Hungerversuche <ol><li> Wenn der P. chrysogenum-Stamm von Interesse auf Reis (&#39;grüne Reis &quot;) gehalten, legen 2-3 Reiskörner mit sporenbildende Mycel in eine 1,5-ml-Mikrozentrifugenröhrchen abgedeckt. Füllen sie mit 500 ul YGG (10 g / l KCl, 20 g / l Glucose, 10 g / l Hefe-Stickstoffbase, 5 g / l K 2 HPO 4, 20 g / l Hefeextrakt). <ol><li> Das Röhrchen vortexen für 30 Sekunden, so dass Sporen aus dem Reis effizient zu lösen. </li><li> Das Röhrchen für 1 Tag bei Raumtemperatur (zB zwischen 20 und 25 ° C). </li><li> Bereiten Sie eine 1/50 Verdünnung dieser Sporensuspension in sterilem Leitungswasser, gut mischen. </li></ol></li><li> Wenn der P. chrysogenum-Stamm von Interesse auf einer Agarplatte (zB YGG Agarplatte) gehalten wird, übertragen kleine Stücke von dem Mycel in eine 1,5-ml-Mikroröhrchen mit 400 ul sterilem Leitungswasser und etwa 100 mg glArschperlen mit Hilfe eines sterilen Zahnstocher oder Pipettenspitze. <ol><li> Vortex das Rohr für 2 Minuten, so dass das Myzel fragmentiert. Mit den Inhalt des Röhrchens sofort. </li></ol></li></ol> 2. Vorbereitende Arbeiten für die Kultivierung von P. chrysogenum auf Starvation Pads <ol><li> Wechseln Sie auf einer Heizplatte und setzen Sie ihn auf etwa 60 ° C. </li><li> Man löst 2 g Agarose in 100 ml Wasser durch Kochen der Lösung in einem Mikrowellenofen zu nutzen. Darauf achten, dass diese Lösung nach dem Erhitzen völlig klar. Wenn es nicht ist, zu kochen, bis es wieder die Agarose vollständig gelöst ist. Lassen Sie die Agaroselösung abkühlen auf etwa 60 ° C vor dem Gebrauch. </li><li> Füllen 1,5 ml Mikrozentrifugenröhrchen (2-4, abhängig von der Anzahl der Proben) mit 400 ul sterilem Leitungswasser jeweils (keine zusätzlichen Verbindungen zugesetzt) ​​oder 400-x ul (Zugabe von x &amp; mgr; l der Lösung der Verbindung in Schritt 2.5) und sie auf der Heizplatte für mindestens 1 min, so daß der Water innen erwärmt sich. </li><li> Platzieren Objektträger, die einen zentralen Hohlraum für mindestens 1 min enthalten auf der Heizplatte. </li><li> Fügen Sie 400 ul 2% igen der Lösung in der 1,5 ml Mikrozentrifugenröhrchen und kurz vortexen. Nach diesem Schritt, wenn gewünscht, fügen Sie zusätzliche Verbindungen (dh 1 uM Rapamycin). Wenn dies geschehen ist, Wirbel kurz nachdem jeder zusätzliche Substanz in das Röhrchen pipettiert. Setzen Sie die Rohre wieder auf die Heizung Tabelle vorzeitige Erstarrung zu verhindern. HINWEIS: Das Gesamtvolumen der Mikrozentrifugenröhrchen sollten 800 ul sein. </li></ol> 3. Vorbereitung der Objektträger mit einem Gehalt Starvation Pads <ol><li> Pipette 140 ul der Agarose-Lösung in den Hohlraum des Objektträgers (die immer noch auf der Heizplatte befindet). Versuchen Sie zu vermeiden, die Luftblasen, wenn möglich. </li><li> Unmittelbar danach ein Deckglas auf den Agarose-Lösung. Hinweis: das wird in einer flachen Oberfläche führen. </li><li> Setzen Sie den MikroRahmen Rutsche auf dem Labortisch für ca. 4 min, damit das Agarose-Pad zu verfestigen. </li><li> Entfernen Sie vorsichtig das Deckglas aus der Agarose-Pad, indem Sie sie mit Hilfe einer Daumen oder Zeigefinger (Handschuhe, um eine Verunreinigung zu vermeiden!). </li><li> Legen Sie die Objektträger mit dem Pad in einen Nassraum, um ein Austrocknen zu verhindern. Empfehlung: Verwenden Sie eine leere Spitze-Box, die noch der Einsatz zur Aufnahme der Pipettenspitzen. Hinzufügen sterilem Wasser auf die Tabelle, so dass der Boden bedeckt. Legen Sie die Objektträger auf den Einsatz und schließen Sie die Box. </li></ol> 4. Impfen des Hunger-Pads mit P. chrysogenum und Inkubation <ol><li> Pipette 5 ul der Sporen 1/50 Verdünnung (wenn die Kulturen wurden für Reis angebaut) oder 5 &amp; mgr; l der unverdünnten Lösung, die Mycel-Fragmente auf der Mitte des Hunger Pad (wenn die Kulturen wurden auf einer Agarplatte gezüchtet). </li><li> Schließen Sie den Nassraum und wickeln Sie es in eine Plastiktüte (dieser dient alszusätzlichen Schutz vor Austrocknung der Hunger-Pads). Achten Sie darauf, das Kästchen zu viel, da sonst die Impfung Tropfen gestört werden zu bewegen. </li><li> Bewahren Sie die Box verpackt bei RT für mindestens 20 Stunden vor der Analyse der Proben. </li></ol> 5. Mikroskopische Analyse der Proben <ol><li> Nach 20 h Inkubation werden die Proben bereit für die mikroskopische Analyse; legen Sie die Objektträger auf trockenen Tissue-Papier (der Boden neigt nass werden). </li><li> Pipette eine kleine Menge Wasser (ca. 50 ul) auf die Hunger-Pad. Setzen Sie ein Deckglas auf das Pad und Squeeze-out überschüssige Wasser. Entfernen Sie das überschüssige Wasser mit einem Papiertaschentuch. </li><li> Legen Sie die Objektträger auf die Beobachtung Tisch des Fluoreszenzmikroskops. Um einen Überblick über Myzelwachstum erhalten, verwenden Sie ein 20X Ziel. Verwenden 63X oder 100X Ziele für die Untersuchung der Lokalisation von GFP in den Hyphen. Um allmähliche Austrocknen der Probe zu verhindern nicht die Proben zu analysierenlänger als 15 Minuten, bevor sie sie wieder in den Nassraum. </li><li> Wiederholen 5.3 in regelmäßigen Abständen (zB nach 40 h und 60 h Wachstum). HINWEIS: Die Probe kann wieder in die feuchte Kammer gestellt werden. Es ist nicht notwendig, um das Deckglas zu entfernen, da sie sich nicht auf Myzelwachstum. </li></ol>

<ol>
	<li>Fischer, F., Hamann, A., Osiewacz, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+quality+control:+an+integrated+network+of+pathways.">Mitochondrial quality control: an integrated network of pathways.</a> Trends Biochem. Sci. 37 (7), 284-292 (2012).</li><li>Pollack, J. K., Harris, S. D., Marten, 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=Autophagy+in+filamentous+fungi.">Autophagy in filamentous fungi.</a> Fungal Genet. Biol. 46 (1), 1-8 (2009).</li><li>Scheckhuber, C. Q., Osiewacz, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Podospora+anserina:+a+model+organism+to+study+mechanisms+of+healthy+ageing.">Podospora anserina: a model organism to study mechanisms of healthy ageing.</a> Mol. Genet. Genomics. 280 (5), 365-374 (2008).</li><li>Pinan-Lucarr&#233;, B., Iraqui, I., Clav&#233;, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Podospora+anserina+target+of+rapamycin.">Podospora anserina target of rapamycin.</a> Curr. Genet. 50 (1), 23-31 (2006).</li><li>Kikuma, T., Ohneda, M., Arioka, M., Kitamoto, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+analysis+of+the+ATG8+homologue+Aoatg8+and+role+of+autophagy+in+differentiation+and+germination+in+Aspergillus+oryzae.">Functional analysis of the ATG8 homologue Aoatg8 and role of autophagy in differentiation and germination in Aspergillus oryzae.</a> Eukaryot. Cell. 5 (8), 1328-1336 (2006).</li><li>Pinan-Lucarr&#233;, B., Balguerie, A., Clav&#233;, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+cell+death+in+Podospora+autophagy+mutants.">Accelerated cell death in Podospora autophagy mutants.</a> Eukaryot. Cell. 4 (11), 1765-1774 (2005).</li><li>Veneault-Fourrey, C., Barooah, M., Egan, M., Wakley, G., Talbot, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagic+fungal+cell+death+is+necessary+for+infection+by+the+rice+blast+fungus.">Autophagic fungal cell death is necessary for infection by the rice blast fungus.</a> Science. 312 (5773), 580-583 (2006).</li><li>Bartoszewska, M., Kiel, J. A., Bovenberg, R. A., Veenhuis, M., van der Klei, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagy+deficiency+promotes+beta-lactam+production+in+Penicillium+chrysogenum.">Autophagy deficiency promotes beta-lactam production in Penicillium chrysogenum.</a> Appl. Environ. Microbiol. 77 (4), 1413-1422 (2011).</li><li>Meijer, W. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peroxisomes+are+required+for+efficient+penicillin+biosynthesis+in+Penicillium+chrysogenum.">Peroxisomes are required for efficient penicillin biosynthesis in Penicillium chrysogenum.</a> Appl. Environ. Microbiol. 76 (17), 5702-5709 (2010).</li><li>Cubitt, A. B., Heim, R., Adams, S. R., Boyd, A. E., Gross, L. A., Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding,+improving+and+using+green+fluorescent+proteins.">Understanding, improving and using green fluorescent proteins.</a> Trends Biochem. Sci. 20 (11), 448-455 (1995).</li><li>Jung, C. H., Ro, S. H., Cao, J., Otto, N. M., Kim, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mTOR+regulation+of+autophagy.">mTOR regulation of autophagy.</a> FEBS Lett. 584 (7), 1287-1295 (2010).</li><li>Hickey, P. C., Read, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+living+cells+of+Aspergillus+in+vitro.">Imaging living cells of Aspergillus in vitro.</a> Med. Mycol. 47, S110-S119 (2009).</li></ol>

The author has nothing to disclose.

Die hier vorgestellte Methode ermöglicht die bequeme und reproduzierbare Untersuchung der Autophagie in P. chrysogenum. Beispielsweise kann es zum Screening der Wirksamkeit von verschiedenen Verbindungen, ob sie zur Modulation der autophagy Reaktion dieses Pilzes sind oder nicht verwendet werden. Die Ergebnisse zeigen, dass mit Rapamycin Hemmung der TOR-Signalisierung führt zu einer deutlichen Induktion der Autophagie in P. chrysogenum, die auch für andere Organismen 11 gezeigt. <p cl...

Fadenpilze sind ausgezeichnete Modellsysteme zur Untersuchung von Entwicklungsprozessen. Sie bieten mehrere experimentelle Vorteile wie billige Anbau, eine hohe Zahl von Nachkommen und genetische Zugänglichkeit. Der letzte Punkt ist von besonderer Bedeutung für den Bau der Transformanten, die die Untersuchung der Bedeutung der so weit nicht charakterisierte Gene für verschiedene zelluläre Mechanismen ermöglichen. Filamentöse Pilze haben wesentlich zur Aufklärung von mehreren Elementen und Mechanismen der zellulären Qualitätskontrolle Wege wie Protease-Aktivität zum Abbau von anomalen Proteinen mitochondrialen Dynamik zum Aufrechterhalten mitochondrialen Integrität und autophagy zur Entfernung von Überschuß und / oder gestörte Zellkomponenten und zum Aufrechterhalten Zelllebensfähigkeit in Zeiten der Hungersnot 1,2,3. Es gibt verschiedene experimentelle Techniken für das Studium der Autophagie in Fadenpilzen 2 zur Verfügung: (i) Untersuchung der Vakuolen if enthaltenen dichten phage Stellen bei Proteasen werden durch Transmissionselektronenmikroskopie 4 inhibiert, (ii) Darstellung von Autophagosomen durch Überwachen GFP-Atg8 Brennpunkte über Fluoreszenzmikroskopie 5,6 und (iii) Detektion angesäuert autophagosomalen Strukturen unter Verwendung der Fluoreszenzfarbstoff monodansyl Cadaverin 7. Hier wird ein neues Verfahren zum Züchten von Penicillium chrysogenum zur autophagy Studien vorgestellt. Das wichtigste Element ist der &quot;Hunger-Pad&quot;, das lediglich aus 1% Agarose in sterilisierte Leitungswasser gelöst. Zusätzliche Verbindungen (zB Stressoren, Abfänger, autophagy Modulatoren) auf die Unterlage so lange sie keine Autofluoreszenz angezeigt hinzugefügt. Das Kissen wird in Objektträgern, die einen flachen zentralen Hohlraum enthalten, entfernt. Dieses Pad in impft entweder mit einer Sporensuspension oder mit kleinen Mycelfragmente. Letzteres ist sinnvoll, wenn die Belastung von Interesse nicht sporulate effizient (zB Δ ATG1 Stämme 8). Die Objektträger werden in feuchten Kammern positioniert, um ein Austrocknen der Probe zu verhindern (diese können einfach mit leeren Pipettenspitze Boxen gebaut werden) und bei Raumtemperatur inkubiert. P. chrysogenum ist in der Lage, für ein paar Tage unter diesen Bedingungen wachsen. Autophagie kann mikroskopisch durch vakuoläre Erweiterung, die eine positive Marker für Pilz Autophagie ist zu beachten. In diesem Beitrag einem P. chrysogenum Stamm (Wisconsin 54-1255) verwendet wird, das grünes fluoreszierendes Protein, das an Peroxisomen durch ihre C-terminalen &quot;SKL&quot; Sequenz 9 ausgerichtet ist bildet. Daher ist es möglich, die Verschlechterung von Peroxisomen überwachen. Es ist möglich, unter Verwendung von geeigneten Lokalisierungssignale kenn auch andere Kompartimente der Zelle (zB Mitochondrien) und ihre Abbau analysieren. Obwohl Daten aus P. chrysogenum Ws54-1255 (GFP-SKL) wird hier dargestellt, ist es durchaus möglich,um den &quot;Hunger-Pad &#39;Methode auch für andere Fadenpilze verwenden (zB Neurospora crassa, Sordaria macrospora, Aspergillus-Arten, etc.).

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			<td height="21" style="height:21px;width:216px;">Name of Reagent/ Equipment</td>
			<td style="width:71px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
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			<td height="105" style="height:105px;width:216px;">Microscope slides with central cavity</td>
			<td style="width:71px;">Carl Roth GmbH, Karlsruhe, Germany</td>
			<td style="width:119px;">H884.1</td>
			<td>These can be used multiple times after cleaning.</td>
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			<td height="105" style="height:105px;width:216px;">Glass beads</td>
			<td style="width:71px;">Carl Roth GmbH, Karlsruhe, Germany</td>
			<td style="width:119px;">A553.1</td>
			<td>Diameter: 0.25 - 0.50 mm</td>
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analysis of autophagy in penicillium chrysogenum by using starvation pads in combination with fluorescence microscopy

The study of cellular quality control systems has emerged as a highly dynamic and relevant field of contemporary research. It has become clear that cells possess several lines of defense against damage to biologically relevant molecules like nucleic acids, lipids and proteins. In addition to organelle dynamics (fusion/fission/motility/inheritance) and tightly controlled protease activity, the degradation of surplus, damaged or compromised organelles by autophagy (cellular &#8216;self-eating&#8217;) has received much attention from the scientific community. The regulation of autophagy is quite complex and depends on genetic and environmental factors, many of which have so far not been elucidated. Here a novel method is presented that allows the convenient study of autophagy in the filamentous fungus Penicillium chrysogenum. It is based on growth of the fungus on so-called &#8216;starvation pads&#8217; for stimulation of autophagy in a reproducible manner. Samples are directly assayed by microscopy and evaluated for autophagy induction / progress. The protocol presented here is not limited for use with P. chrysogenum and can be easily adapted for use in other filamentous fungi.

Um die Nützlichkeit des Protokolls über Peroxisomen Abbau in der P. detailliert zeigen chrysogenum-Stamm Ws54-1255 (GFP-SKL) analysiert. In diesem Stamm GFP-SKL ist in der Regel in die Peroxisomen 9 importiert. Dies führt zu dem Auftreten von mehrfachen Kugelformen, wenn die Probe durch Fluoreszenzmikroskopie analysiert. Wenn Autophagie auftritt, vergrößern Vakuolen. GFP-SKL wird durch Autophagie (pexophagy) in Vakuolen integriert. Aufgrund der Tatsache, dass GFP ist resistent gegen den...

Watch this Scientific Journal Video about Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy at JoVE.com

Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

A convenient and powerful method for studying autophagy in Penicillium chrysogenum by using starvation pads (mixtures of agarose and tap water in a microscope slide containing a central cavity) is presented here.

Die Analyse der Autophagie in<em&gt; Penicillium chrysogenum</em&gt; Mithilfe von Starvation Pads in Kombination mit Fluoreszenzmikroskopie

The study of cellular quality control systems has emerged as a highly dynamic and relevant field of contemporary research. It has become clear that cells ...

analysis-autophagy-penicillium-chrysogenum-using-starvation-pads

Research

JoVE Journal

Biology

Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

8.5K Aufrufe.  Senckenberg Research Institute. A convenient and powerful method for studying autophagy in Penicillium chrysogenum by using starvation pads (mixtures of agarose and tap water in a microscope slide containing a central cavity) is presented here.

Serie: Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

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 ...

Forschung

Biologie

Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine1. This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)1,10. Indeed, we have shown that human prostate cancer cells CWR22Rv1 are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy (or macroautophagy)1,2,3. Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation4,5. Although the essential components of this pathway are well-characterized6,7,8,9, many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy11,12.
Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early stages of autophagy induction. With commercially available digital image analysis applications, we can readily obtain statistical information about autophagosome and lysosome number, size, distribution, and degree of colocalization from any imaged cell. This information allows us to precisely track the progress of autophagy in living cells and enables our continued investigation into the role of autophagy in cancer chemotherapy.

Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

Quantitative Analyse von Autophagie mit Advanced 3D Fluoreszenzmikroskopie

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, ...

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for using FISH to quantify the number of mRNAs in single yeast cells. Cells can be grown in any condition of interest and then fixed and made permeable. Subsequently, multiple single-stranded deoxyoligonucleotides conjugated to fluorescent dyes are used to label and visualize mRNAs. Diffraction-limited fluorescence from single mRNA molecules is quantified using a spot-detection algorithm to identify and count the number of mRNAs per cell. While the more standard quantification methods of northern blots, RT-PCR and gene expression microarrays provide information on average mRNAs in the bulk population, FISH facilitates both the counting and localization of these mRNAs in single cells at single-molecule resolution.

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

This protocol describes an experimental procedure for performing Fluorescence in situ Hybridization (FISH) for counting mRNAs in single cells at single-molecule resolution.

Visualisierung und Analyse von mRNA Moleküle mittels Fluoreszenz<em&gt; In Situ</em&gt; Hybridisierung in<em&gt; Saccharomyces cerevisiae</em

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

In-vivo-4-Dimensional-Tracking von hämatopoetischen Stamm-und Vorläuferzellen im erwachsenen Maus Schädeldachknochenmark

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation.

Fecal Glucocorticoid-Analyse: Nicht-invasive Monitoring-Adrenal in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

Visualizing Stromule Frequency with Fluorescence Microscopy

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but whose functions remain mysterious. Alongside growing attention on the role of chloroplasts in coordinating plant responses to stress, interest in stromules and their relationship to chloroplast signaling dynamics has increased in recent years, aided by advances in fluorescence microscopy and protein fluorophores that allow for rapid, accurate visualization of stromule dynamics. Here, we provide detailed protocols to assay stromule frequency in the epidermal chloroplasts of Nicotiana benthamiana, an excellent model system for investigating chloroplast stromule biology. We also provide methods for visualizing chloroplast stromules in vitro by extracting chloroplasts from leaves. Finally, we outline sampling strategies and statistical approaches to analyze differences in stromule frequencies in response to stimuli, such as environmental stress, chemical treatments, or gene silencing. Researchers can use these protocols as a starting point to develop new methods for innovative experiments to explore how and why chloroplasts make stromules.

Protocols to investigate the dynamics of chloroplast stromules, the stroma-filled tubules that extend from the surface of chloroplasts, are described.

Visualizing Stromulus Frequenz mit Fluoreszenzmikroskopie

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but ...

Activating Autophagy by Aerobic Exercise in Mice

Autophagy is a lysosomal degradation pathway essential for cell homeostasis, function and differentiation. Under stress conditions, autophagy is induced and targets various cargos, such as bulk cytosol, damaged organelles and misfolded proteins, for degradation in lysosomes. Resulting nutrient molecules are recycled back to the cytosol for new protein synthesis and ATP production. Upregulation of autophagy has beneficial effects against the pathogenesis of many diseases, and pharmacological and physiological strategies to activate autophagy have been reported. Aerobic exercise is recently identified as an efficient autophagy inducer in multiple organs in mice, including muscle, liver, heart and brain. Here we show procedures to induce autophagy in vivo by either forced treadmill exercise or voluntary wheel running. We also demonstrate microscopic and biochemical methods to quantitatively analyze autophagy levels in mouse tissues, using the marker proteins LC3 and p62 that are transported to and degraded in lysosomes along with autophagosomes.

Autophagy activation is beneficial in the prevention of a number of diseases. One of the physiological approaches to induce autophagy in vivo is physical exercise. Here we show how to activate autophagy by aerobic exercise and measure autophagy levels in mice.

Die Aktivierung Autophagy von Aerobic-Übung bei Mäusen

Autophagy is a lysosomal degradation pathway essential for cell homeostasis, function and differentiation. Under stress conditions, autophagy is induced ...

Open-source Single-particle Analysis for Super-resolution Microscopy with VirusMapper

Super-resolution fluorescence microscopy is currently revolutionizing cell biology research. Its capacity to break the resolution limit of around 300 nm allows for the routine imaging of nanoscale biological complexes and processes. This increase in resolution also means that methods popular in electron microscopy, such as single-particle analysis, can readily be applied to super-resolution fluorescence microscopy. By combining this analytical approach with super-resolution optical imaging, it becomes possible to take advantage of the molecule-specific labeling capacity of fluorescence microscopy to generate structural maps of molecular elements within a metastable structure. To this end, we have developed a novel algorithm &#8212; VirusMapper &#8212; packaged as an easy-to-use, high-performance, and high-throughput ImageJ plugin. This article presents an in-depth guide to this software, showcasing its ability to uncover novel structural features in biological molecular complexes. Here, we present how to assemble compatible data and provide a step-by-step protocol on how to use this algorithm to apply single-particle analysis to super-resolution images.

This manuscript uses the Fiji-based open-source software package VirusMapper to apply single-particle analysis to super-resolution microscopy images in order to generate precise models of nanoscale structure.

Open-Source-Einzelpartikelanalyse für Super Resolution Mikroskopie mit VirusMapper

Super-resolution fluorescence microscopy is currently revolutionizing cell biology research. Its capacity to break the resolution limit of around 300 nm ...

Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy

Live-cell imaging is a microscopy technique used to examine cell and protein dynamics in living cells. This imaging method is not toxic, generally does not interfere with cell physiology, and requires minimal experimental handling. The low levels of technical interference enable researchers to study cells across multiple cycles of mitosis and to observe meiosis from beginning to end. Using fluorescent tags such as Green Fluorescent Protein (GFP) and Red Fluorescent Protein (RFP), researchers can analyze different factors whose functions are important for processes like transcription, DNA replication, cohesion, and segregation. Coupled with data analysis using Fiji (a free, optimized ImageJ version), live-cell imaging offers various ways of assessing protein movement, localization, stability, and timing, as well as nuclear dynamics and chromosome segregation. However, as is the case with other microscopy methods, live-cell imaging is limited by the intrinsic properties of light, which put a limit to the resolution power at high magnifications, and is also sensitive to photobleaching or phototoxicity at high wavelength frequencies. However, with some care, investigators can bypass these physical limitations by carefully choosing the right conditions, strains, and fluorescent markers to allow for the appropriate visualization of mitotic and meiotic events.

Here, we present live-cell imaging which is a non-toxic microscopy method that allows researchers to study protein behavior and nuclear dynamics in living fission yeast cells during mitosis and meiosis.

Untersuchung der Mitotic and Meiotic Fission Yeast Nuclear Dynamics durch Fluoreszenz-Livezellmikroskopie

Live-cell imaging is a microscopy technique used to examine cell and protein dynamics in living cells. This imaging method is not toxic, generally does ...

Oligomerization Dynamics of Cell Surface Receptors in Living Cells by Total Internal Reflection Fluorescence Microscopy Combined with Number and Brightness Analysis

Despite the importance and ubiquity of receptor oligomerization, few methods are applicable for detecting clustering events and measuring the degree of clustering. Here, we describe an imaging approach to determine the average oligomeric state of mEGFP-tagged-receptor homocomplexes in the membrane of living cells. The protocol is based on Total Internal Reflection Fluorescence (TIRF) microscopy combined with Number and Brightness (N&#38;B) analysis. N&#38;B is a method similar to fluorescence-correlation spectroscopy (FCS) and photon counting histogram (PCH), which are based on the statistical analysis of the fluctuations of the fluorescence intensity of fluorophores diffusing in and out of an illumination volume during an observation time. In particular, N&#38;B is a simplification of PCH to obtain information on the average number of proteins in oligomeric mixtures. The intensity fluctuation amplitudes are described by the molecular brightness of the fluorophore and the average number of fluorophores within the illumination volume. Thus, N&#38;B considers only the first and second moments of the amplitude distribution, namely, the mean intensity and the variance. This is, at the same time, the strength and the weakness of the method. Because only two moments are considered, N&#38;B cannot determine the molar fraction of unknown oligomers in a mixture, but it only estimates the average oligomerization state of the mixture. Nevertheless, it can be applied to relatively small time series (compared to other moment methods) of images of live cells on a pixel-by-pixel basis, simply by monitoring the time fluctuations of the fluorescence intensity. It reduces the effective time-per-pixel to a few microseconds, allowing acquisition in the time range of seconds to milliseconds, which is necessary for fast oligomerization kinetics. Finally, large cell areas as well as sub-cellular compartments can be explored.

We describe an imaging approach for the determination of the average oligomeric state of mEGFP-tagged-receptor oligomers induced by ligand binding in the plasma membrane of living cells. The protocol is based on Total Internal Reflection Fluorescence (TIRF) microscopy combined with Number and Brightness (N&#38;B) analysis.

Oligomerisierungsdynamik von Zelloberflächenrezeptoren in lebenden Zellen durch totale interne Reflexionsfluoreszenzmikroskopie kombiniert mit Zahlen- und Helligkeitsanalyse

Despite the importance and ubiquity of receptor oligomerization, few methods are applicable for detecting clustering events and measuring the degree of ...