We gratefully acknowledge Dr. Deborah L. Gumucio as our advisor and for her invaluable support in defining the culture and imaging methods. We also thank Dr. Jim Brodie, Dr. Hong-Xiang Lu, Dr. Charlotte Mistretta, and Dr. Ann Grosse for their contributions to the development of the whole intestine organ culture system. Helpful discussions on imaging provided excellent advice from Dr. Chip Montrose, Michael Czerwinski and Sasha Meshinchi. All imaging was performed in the Microscopy and Image Analysis Laboratory at the University of Michigan. Funding support was provided by NIH R01 DK065850.

NOTA: Tutti i topi sono stati trattati umanamente utilizzando protocolli approvati dalla University of Michigan Medical School Unità per la Medicina di Laboratorio animali e secondo le linee guida della Commissione di Ateneo per l&#39;uso e la cura degli animali. 1. intero sistema Cultura Organo <ol><li> Preparazione dei supporti e piastre di coltura <ol><li> In una cappa di coltura tissutale, rimuovere 5 ml di BGJb supporto dalla bottiglia stock e aggiungere 5 ml di Pen / Strep. Preparare uno stock di lavoro di media in un tubo conico da 50 ml, con l&#39;aggiunta di 1 ml di 5 mg / ml di acido ascorbico a 49 ml di BGJb media (con Pen / Strep). </li><li> Preparare una piastra di coltura ben 6 con l&#39;aggiunta di 1 ml di sotto ciascuna delle transwells. NOTA: Se non si utilizzano tutti i 6 transwells, spostare transwells in più in una sterile piatto 6 e fresco per un uso successivo. Aggiungere 3 ml di lavorare BGJb media per ciascuna delle tre piastre di Petri sterili 10 centimetri. </li></ol></li><li> Preparazione per la dissezione <ol><li> Immergere gli strumenti di dissezione nel 70% etanolo perNol ed essere sicuri di mantenere gli strumenti puliti durante il lavoro. </li><li> Impostare l&#39;area dissezione con un grande secchio di ghiaccio e posizionare la piastra di coltura ben 6 e 10 centimetri di Petri con BGJb multimediale su ghiaccio. Lavorare sul ghiaccio il più possibile mentre dissezione e preparare l&#39;intestino per la cultura. </li><li> Anestetizzare adulto topi femmina in una camera con isofluorane (100 ml) prima euthanization da dislocazione cervicale per la raccolta di intestino fetale. </li><li> Dopo la raccolta i feti dalla madre, in scena ogni feto con attenzione secondo la Theiler messa in scena tabella 13. Non fare affidamento nei giorni post-coito per determinare l&#39;età di ogni feto come variazioni fino a 24 ore in fase di sviluppo sono abitualmente osservati all&#39;interno di una singola cucciolata. </li></ol></li><li> Dissezione di intestini fetali <ol><li> Euthanize feti di decapitazione prima della rimozione di intestino. </li><li> Sezionare ogni intestino di 1x Dulbecco Phosphate-Buffered Saline (DPBS) e poi place in una piastra di Petri 10 centimetri con il lavoro BGJb media. </li><li> Rimuovere con cautela la milza dallo stomaco e il pancreas dallo stomaco e duodeno superiore. </li><li> Separare delicatamente il omento avendo cura di lasciare il omento divisoria per quanto possibile e separare connessioni solo sufficiente a permettere l&#39;intestino da raddrizzare. NOTA: Per intestini di età superiore a E14.5 o quelli in coltura più di 24 ore, separare delicatamente l&#39;intestino in 3 segmenti uguali per consentire contenuto luminale di fluire attraverso l&#39;intestino ed essere espulsi dalle estremità tagliate. Tuttavia, per le culture iniziato prima E13.5, attendere fino a dopo 24 ore di coltura prima di separare i tre segmenti di intestino per permettere la sierosa di crescere correttamente sulla lunghezza dell&#39;intestino. </li><li> Utilizzare una pipetta bocca per trasferire i pezzi intestinali sui transwells della piastra di coltura (1.1.2). </li><li> Riposizionare delicatamente l&#39;intestino, se necessario in modo che siano dritti alla transwell. NOTA: Una volta che gli intestini cominciano muoversi contenuto luminale attraverso il tubo, eventuali pieghe a livello intestinale causerà un backup e danni per l&#39;intestino. </li></ol></li><li> Cultura e trattamento <ol><li> Rimuovere il supporto da sotto il transwell, aggiungere 700 ml di mezzi di trattamento (dei media che lavorano con l&#39;aggiunta di proteine ​​ricombinanti o inibitori farmacologici) sotto il transwell. </li><li> Aggiungere 300 ml di supporti trattamento goccia a goccia sulla parte superiore dell&#39;intestino e lasciare in ammollo attraverso il transwell. Riposizionare l&#39;intestino, se necessario. </li><li> Cambiare mezzi trattamento almeno una volta al giorno o più spesso a seconda del tempo di dimezzamento del reagente trattamento. </li></ol></li><li> Preparazione di proteine ​​imbevuto agarosio perline per una fonte localizzata di reagente trattamento <ol><li> Risospendere le perline agarosio nel loro contenitore e trasferire 100 ml di perline agarosio in una provetta da 1,5 ml microcentrifuga. </li><li> Riempire il volume rimanente del tubo con sterile 1x Phosphate-Buffered Saline (PBS) e mescolare le perle di lavarli. Collocare la provetta da microcentrifuga in un rack per alcuni minuti per consentire le perle di depositarsi sul fondo e poi pipettare fuori dalla PBS in cima alle perline. Riempire la provetta per microcentrifuga con 1x PBS sterile e ripetere il processo di lavaggio altre due volte. </li><li> Preparare la proteina di interesse a due volte la concentrazione desiderata per il trattamento. </li><li> Mescolare 5 ml di perline agarosio lavato con 5 ml di proteina magazzino 2x e agitare delicatamente le perline nella proteina. Porre la provetta in ghiaccio per 1 ora, mescolando delicatamente ogni 10-15 min. </li><li> Sciacquare le perline brevemente sterile 1x PBS prima di mettere le perline su intestini. </li></ol></li><li> Posizionamento di perline agarosio <ol><li> Posizionare delicatamente le perline agarosio sulla parte superiore dell&#39;intestino utilizzando una pipetta bocca con aghi capillari tirato. Posizionare le perle con estrema cautela in quanto un trasporto sicuro danneggia l&#39;intestino e prevenire lo sviluppo dei villi nella zona lesa. </li><li> Posizionare il doppio delle perle come sono necessari per l&#39;analisi in quanto l&#39;intestino saranno sottoposti a movimenti peristaltici e circa la metà delle perline poste rotolerà fuori degli intestini oltre il tempo di coltura. </li></ol></li><li> Fissazione di intestino in coltura <ol><li> Rimuovere con cautela il supporto di trattamento da sotto la transwell e permettere l&#39;intestino di aria secca per 3 min. </li><li> Aggiungere 1 ml di fissativo sotto la transwell per 2 minuti, quindi coprire la parte superiore dell&#39;intestino con 2 ml di fissativo per il resto del tempo di fissazione. Fissare con 4% paraformaldeide O / N a 4 ° C o per 2 ore a temperatura ambiente. </li></ol></li></ol> 2 Imaging di Intestino fisse <ol><li> Immagini Wholemount <ol><li> Posizionare l&#39;intero intestino (con fluorescenza endogena) su un vetrino con 100 ml di 1x DPBS. Usare pinze per organizzare delicatamente l&#39;intestino. </li><li> Utilizzare un tessuto laboratorio per rimuovere con attenzione i DPBS e immediatamente aggiungere 100 ml di glicerolo 70% per rendere il mo tessutiri trasparente e aumentare la possibile profondità di imaging. NOTA: Se si desidera ulteriore penetrazione dell&#39;intestino, invece di montare l&#39;intestino in 70% glicerolo, immergere l&#39;intestino in poche gocce di soluzione di messa a fuoco libero per 10-30 min. Pipettare fuori la soluzione messa a fuoco chiara e montare l&#39;intestino con il Monte Chiaro. </li><li> Immergere ciascuno dei quattro angoli di un coprioggetto in creta e raccogliere una piccola quantità di argilla da utilizzare come distanziatori tra il vetrino e coprioggetto per mantenere il coprioggetto da appiattimento dell&#39;intestino. </li><li> Sigillare il coprioggetto sul vetrino con VALAP fusa applicato con un batuffolo di cotone. </li><li> Immagine l&#39;intestino su entrambi un microscopio confocale in posizione verticale o invertita. Si prega di fare riferimento alla discussione per ulteriori dettagli. </li></ol></li><li> Vibratome sezionamento di intestino fissi (per la vista in sezione trasversale di strutture intestinali) <ol><li> Intestini incorporare nel 7% di agarosio in piccoli stampi di plastica (10 x 10 x 15 mm) e consentire i blocchi di agarosio araffreddare e solidificare. </li><li> Rimuovere i blocchi di agarosio dagli stampi di plastica e blocchi di colla di agarosio alla fase di raccolta vibratome con colla istantanea. </li><li> Riempire la fase della raccolta con il freddo ghiaccio 1x DPBS. </li><li> Tagliare sezioni ad uno spessore compreso tra 100-150 micron. Per le sezioni più spesse utilizzano le soluzioni di compensazione (descritti nella sezione 2.1.2) per visualizzare più in profondità la sezione trasversale. </li><li> Versare vibratome sezioni dalla fase di raccolta in un pozzetto di una piastra da 6 pozzetti per la conservazione a 4 ° C. </li></ol></li><li> Immunofluorescenza colorazione dei tessuti, vibratome sezionati fissi <ol><li> Posizionare 5-12 sezioni vibratome per bene in un 24-pozzetti con 1x DPBS. </li><li> Rimuovere 1x DPBS e aggiungere 500 ml di soluzione di permeabilizzazione per pozzetto. Agitare delicatamente i campioni per 25 minuti a temperatura ambiente. </li><li> Dopo permeabilizzazione, lavare i campioni 3 volte con PBS 1x. </li><li> Bloccare i campioni per almeno 30 minuti in 500 ml di Blocking Solution. </li><li> Dopo il blocco, exchange la soluzione di saturazione con 500 ml di anticorpi primari diluiti in soluzione bloccante e mantenere i campioni a 4 ° CO / N. NOTA: Le diluizioni degli anticorpi primari che funzionano bene su sezioni congelate e paraffina generalmente funzionano bene su vibratome sezioni troppo, ma gli anticorpi che richiede il recupero dell&#39;antigene nucleare in genere non funzionano bene con questo protocollo (ad esempio, BrdU). </li><li> Il giorno seguente, lavare i campioni 3 volte per 15 minuti ogni volta con soluzione bloccante. </li><li> Dopo il lavaggio, applicare 500 ml di anticorpo secondario diluito in soluzione bloccante. Avvolgere la piastra di 24 pozzetti in un foglio di alluminio per proteggere i fluorofori dalla luce e rock i campioni per 45 minuti a 2 ore a temperatura ambiente. </li><li> Lavare i campioni 3 volte con PBS 1x per 15 minuti ciascuno e montare le sezioni vibratome su vetrini come descritto nella Sezione 2.4. </li></ol></li><li> Montaggio vibratome sezioni <ol><li> Preparare i vetrini per vibratome il montaggio tagliando fette sottili di double-stinastro ck e metterli lungo i lati lunghi delle diapositive. </li><li> Posizionare con cura 5-10 sezioni vibratome tra il nastro biadesivo sulle diapositive in una goccia di 100 microlitri di PBS 1x. </li><li> Aprire tutte le sezioni e diffondere fuori in un unico livello in tutta la diapositiva. </li><li> Rimuovere eventuali agarosio eccesso o pezzi irregolari che potrebbero impedire un coprioggetto da seduta piatta. </li><li> Utilizzare con cautela un tessuto laboratorio per assorbire l&#39;eccesso di PBS 1x attorno alle sezioni vibratome. </li><li> Aggiungere una goccia di mezzo di montaggio acquoso sulla cima delle sezioni vibratome e poi coprioggetto. </li><li> Sigillare i coprioggetti sui vetrini con fuso VALAP applicato con un batuffolo di cotone. </li><li> Immagine sezioni vibratome su entrambi un microscopio confocale diritta o capovolta. Si prega di fare riferimento alla discussione per ulteriori dettagli sulla selezione di un sistema di imaging. </li></ol></li></ol> 3 Immagini dal vivo di Intestino interi Intestino raccolte da fetuses dopo E12.5, con l&#39;omento collegato lasciato intatto, sviluppare con successo villi in coltura utilizzando il sistema di cui sopra. Pertanto, questo sistema ex vivo permette la cattura di immagini z-sezione live dell&#39;intestino sviluppo che possono essere ricostruite per una vista tridimensionale della morfogenesi nel tempo. <ol><li> Impostazione di immagini dal vivo <ol><li> Utilizzare colla istantanea di aderire una membrana di policarbonato individuo a uno schermo a maglia fine. Questo fornisce un&#39;impalcatura di sostegno per tenere l&#39;intestino in posizione sotto la lente immersione del microscopio confocale montante. Si prega di consultare la sezione di discussione per ulteriori dettagli sulla selezione di microscopi di imaging dal vivo. </li><li> Posizionare lo schermo a rete al centro e di una piastra di coltura. </li><li> Posizionare l&#39;intestino sezionato sulla membrana di policarbonato e aggiungere una goccia di colla istantanea alle due estremità. Utilizzare solo abbastanza colla per apporre l&#39;intestino, ma non ricoprirlo! </li><li> Aggiungi terreni di coltura privo di fenolo rosso sotto il policarbonatomembrana nel centro pozzetto della piastra di coltura. </li><li> Aggiungere acqua al bordo esterno della piastra di coltura per fornire umidità. </li><li> Dal momento che l&#39;intestino fetale subisce onde peristaltiche simili di contrazione nella cultura, aggiungere 100 ml di una soluzione 1: 5 di xilazina in 1x PBS a 3 ml di media per controllare il movimento dell&#39;intestino durante l&#39;imaging. Questo dosaggio controllerà i movimenti intestinali per circa 8-10 ore senza compromettere lo sviluppo dei villi. </li><li> Per una vista trasversale dell&#39;intestino, incorporare gli intestini vivi in ​​una soluzione di agarosio 3-4% e tagliare sezioni spesse (150-500 micron) su un vibratome. Abbinare la rigidità del agarosio con la rigidità dell&#39;intestino essere tagliati ed empiricamente determinata fase di sviluppo. In generale, una soluzione di agarosio al 3% funziona bene per l&#39;intestino di età inferiore E14.5 e una soluzione al 4% funziona bene per l&#39;intestino E15-E16. </li><li> Incollare le sezioni vibratome ad una membrana di policarbonato, apposto su un schermo di maglia (come al punto 3.1.1) ecultura come descritto nella sezione 3.1.2-3.1.6. </li><li> Condurre l&#39;imaging dal vivo utilizzando un microscopio confocale a due fotoni (laser di eccitazione tra 690-1,040 nm) su un supporto verticale con un tavolo sintonizzabile. </li><li> Laser a due fotoni sintonizzato a 900 nm fornisce penetrazione profonda con la migliore risoluzione per i segnali GFP. Riduce i danni ai tessuti durante l&#39;imaging. Inoltre, impostando la potenza del laser per l&#39;emissione più bassa riduce il danno tissutale. Tipicamente per ottenere una buona eccitazione di GFP, utilizzare potenza 12% sul laser a due fotoni. </li></ol></li></ol>

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The authors have no financial conflicts to disclose.

La natura dinamica e le interazioni complesse dei tessuti dell&#39;intestino in via di sviluppo richiede la visualizzazione 3D per avere una comprensione completa di questi eventi morfogenetici. Con la continua evoluzione tecnologia di imaging, la capacità di esaminare villi morfogenesi in dettaglio si sta sviluppando / miglioramento e con esso, la comprensione della comunicazione spaziale e l&#39;interazione durante l&#39;organogenesi è notevolmente migliorata. Metodi di coltura intestini...

Each intestinal villus is composed of two main tissue compartments: an epithelial surface layer and a mesenchymal core. The mouse small intestine is formed at embryonic day 10 when a sheet of endoderm closes and seals to form a tube of epithelium surrounded by mesenchymal cells3. This flat tube of epithelium undergoes rapid proliferation, growing both in length and girth and undergoes dramatic rearrangements involving dynamic cell shape changes1. At the same time, the surrounding mesenchyme also undergoes many developmental processes including the formation of the vascular plexus, differentiation of smooth muscle and recruitment of enteric neurons4. In the proximal small intestine at embryonic day 14.5, condensations (clusters) of Hedgehog- and PDGF-responsive cells begin to form adjacent to the epithelium2,5. Formation of mesenchymal clusters continues to spread along the length of the intestine so that they cover the entirety of the small intestine by embryonic day 16.52. As mesenchymal clusters form, the epithelial cells closest to the clusters begin to withdraw from the cell cycle, while the other epithelial cells continue to proliferate. Those cells directly above the mesenchymal cluster that have withdrawn from the cell cycle begin to change shape as the emerging villus buckles into the lumen. Further growth of the villus is driven in part by the continued proliferation of the epithelium between the emerging villi. The mesenchymal clusters remain tightly adhered to the epithelium of the growing villus and continue to express a variety of signaling molecules. The wave of villus emergence propagates along the length of the small intestine following the formation of mesenchymal clusters. As the intestine continues to grow and the intervillus region extends between emerging villi, new mesenchymal clusters form adjacent to the intervillus epithelium and further rounds of villus emergence and growth ensue6.
Synchronized development of the epithelium and mesenchyme is essential for villus morphogenesis. Signaling molecules are secreted from one layer to the other where receptors receive and transduce the signal message in order to coordinate development between the epithelium and mesenchyme. Mesenchymal clusters act as signaling centers and express a variety of developmental morphogens7-10. Disruption of cluster formation or pattern results in loss of villus emergence and pattern. Inhibition of PDGF signaling results in fewer clusters and fewer villi and those villi that do form are misshapen following the abnormal clusters11. Loss of Hedgehog signaling results in complete loss of cluster formation and failure of villus emergence2,12. Together, these data demonstrate that clusters coordinate development of the villus epithelium with its mesenchymal core.
Using this whole organ culture system, we are able to alter signaling involved in epithelial-mesenchymal cluster cross-talk to determine the role of those signals in villus morphogenesis. Two-photon confocal optical sectioning and reconstruction afford the ability to visualize cluster formation and villus emergence in three-dimensions and better understand the spatial relationships between the mesenchymal clusters and their overlying epithelium. Extending the culture system to four dimensions, we can capture z-stacks of developing clusters and villi over time and observe these interactions. Ultimately, the ability to follow villus development in this manner and observe changes that occur with altered signaling will revolutionize the understanding of epithelial mesenchymal interactions in villus morphogenesis.

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		<tr height="21">
			<td height="21" style="height:21px;width:508px;">Fine dissecting forceps&#160;</td>
			<td style="width:223px;">Fine Science Tools</td>
			<td style="width:133px;">&#160;11254-20</td>
			<td style="width:444px;">2 pairs</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">70% Ethanol</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1x sterile Dulbecco&#39;s Phosphate-Buffered Saline (DPBS)</td>
			<td>Gibco&#160;</td>
			<td>14040-133</td>
			<td style="width:444px;">500 ml</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6 well plates</td>
			<td>Costar</td>
			<td>3516</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">24 well plates</td>
			<td>Costar&#160;</td>
			<td>3524</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">60 x 15 mm petri dishes</td>
			<td>Falcon</td>
			<td>&#160;451007</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transwell plates, 24 mm inserts, 8.0 mm polycarbonate membranes</td>
			<td>Corning Costar&#160;</td>
			<td>3428</td>
			<td style="width:444px;">6 inserts per plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BGJb media</td>
			<td>Invitrogen&#160;</td>
			<td>12591-038</td>
			<td style="width:444px;">500 ml</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PenStrep (10,000U/ml Penicillin; 10,000 mg/ml Streptomycin)</td>
			<td>Gibco</td>
			<td>&#160;15140</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ascorbic Acid</td>
			<td>Sigma&#160;</td>
			<td>A0278</td>
			<td style="width:444px;">make 5 mg/ml stock, filter, aliquot and store at -20 &#176;C</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Mouth pipet (Drummond 1-15 inch aspirator tube assembly)</td>
			<td>Fisher</td>
			<td style="width:133px;">&#160;21-180-10</td>
			<td style="width:444px;">remove the aspirator assembly and replace it with a 1000 &#181;l pipet tip which acts as an adaptor to plug in a 6 inch glass Pasteur pipet.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6 inch glass pasteur pipets</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Agarose beads</td>
			<td>BioRad&#160;</td>
			<td>153-7301</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Capillary Tubes</td>
			<td>World Precision Instruments&#160;</td>
			<td>TW100F-4</td>
			<td style="width:444px;">pull to needles</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">4% Paraformaldehyde</td>
			<td></td>
			<td></td>
			<td style="width:444px;">made in 1 x PBS, pH to 7.3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;"></td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Live Imaging Materials</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Name of Material/Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td style="width:444px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Culture plates</td>
			<td>Falcon&#160;</td>
			<td>353037</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fine mesh stainless steel screen</td>
			<td>purchase at hardware store</td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Polycarbonate membranes</td>
			<td>Thomas scientific&#160;</td>
			<td>4663H25</td>
			<td style="width:444px;">alternatively, cut Corning Costar 3428 membranes off of transwell supports</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Instant glue</td>
			<td>purchase at hardware store</td>
			<td style="width:133px;">gel based preferrably</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">35 x 10 mm plates</td>
			<td>Falcon&#160;</td>
			<td style="width:133px;">351008</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">7% agarose</td>
			<td>Sigma</td>
			<td>&#160;A9414</td>
			<td style="width:444px;">prepare w/v in 1x DPBS, heating to dissolve in a waterbath</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">minutien pins</td>
			<td>Fine Science Tools&#160;</td>
			<td style="width:133px;">26002-20</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phenol red free media (DMEM)</td>
			<td>Gibco&#160;</td>
			<td style="width:133px;">21063-029</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Xylazine (100 mg/ml)</td>
			<td>AnaSed&#160;</td>
			<td style="width:133px;">139-236</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Matrigel</td>
			<td>BD</td>
			<td style="width:133px;">356231</td>
			<td style="width:444px;">basement membrane matrix, growth factor reduced, phenol red-free</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">3-4% agarose</td>
			<td>Sigma&#160;</td>
			<td>A9414</td>
			<td style="width:444px;">prepare w/v in 1x DPBS, heating to dissolve in a waterbath</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;"></td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Imaging of fixed intestines</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Name of Material/Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td style="width:444px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">vaseline</td>
			<td style="width:223px;">purchase at pharmacy</td>
			<td></td>
			<td>used to make VALAP: equal parts vaseline, lanolin, paraffin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">lanolin</td>
			<td style="width:223px;">Sigma&#160;</td>
			<td>L7387</td>
			<td>used to make VALAP: equal parts vaseline, lanolin, paraffin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">paraffin</td>
			<td style="width:223px;">Surgipath</td>
			<td>39601006</td>
			<td>used to make VALAP: equal parts vaseline, lanolin, paraffin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">70% glycerol in 1 x PBS</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Focus clear and Mount Clear</td>
			<td>CelExplorer Labs Co.</td>
			<td>&#160;F101-KIT</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Modeling clay</td>
			<td>purchase at art supply store</td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">double stick tape</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">cotton applicator swabs</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">plastic molds, 10mm x 10mm x 5 mm)</td>
			<td>Tissue Tek&#160;</td>
			<td>4565</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">slides</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">coverslips</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">lab wipe</td>
			<td>Kimberly Clark</td>
			<td>34155</td>
			<td style="width:444px;">lint free delicate task wipe</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Theiler staging chart&#160;</td>
			<td></td>
			<td></td>
			<td style="width:444px;"><a href="http://www.emouseatlas.org/emap/ema/theiler_stages/%20downloads/theiler2.pdf">http://www.emouseatlas.org/emap/ema/theiler_stages/ downloads/theiler2.pdf</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Leica SP5X confocal microscope&#160;</td>
			<td>Leica</td>
			<td></td>
			<td style="width:444px;">Used to conduct the live imaging&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Leica DMI 6000 stand&#160;</td>
			<td>Leica</td>
			<td></td>
			<td style="width:444px;">Used to conduct the live imaging&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Aqueous mounting medium (Prolong Gold)</td>
			<td>Molecular Probes&#160;</td>
			<td>P36930</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;"></td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Materials for Immunofluorescence staining of fixed, vibratome sectioned intestines</td>
			<td></td>
			<td></td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Name of Material/Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td style="width:444px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">24 well plate</td>
			<td>Costar</td>
			<td>&#160;3524</td>
			<td style="width:444px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Triton X-100</td>
			<td>Sigma&#160;</td>
			<td>T-8787</td>
			<td style="width:444px;">used to make Permeabilization solution: 0.5% Triton X-100 in 1 x PBS</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Goat serum</td>
			<td></td>
			<td></td>
			<td style="width:444px;">used to make Blocking Solution: 4% Goat serum, 0.1% Tween20 in 1x PBS</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Tween20&#160;</td>
			<td>Sigma</td>
			<td>&#160;P9416</td>
			<td style="width:444px;"></td>
		</tr>
	</tbody>
</table>

mouse fetal whole intestine culture system for ex vivo manipulation of signaling pathways and three-dimensional live imaging of villus development

La maggior parte dei processi morfogenetici nell&#39;intestino fetale sono stati dedotto dalle sezioni sottili di tessuti fissati, fornendo istantanee di cambiamenti nel corso stadi di sviluppo. Informazioni tridimensionale da sezioni seriali sottili può essere difficile da interpretare a causa della difficoltà di ricostruire sezioni seriali perfettamente e mantenere il corretto orientamento del tessuto su sezioni seriali. Recenti scoperte di Grosse et al. 2011 sottolineano l&#39;importanza di tre informazioni dimensionali nella comprensione morfogenesi dei villi sviluppo dell&#39;intestino 1. Ricostruzione tridimensionale delle cellule intestinali singolarmente etichettati dimostrato che la maggior parte delle cellule epiteliali intestinali contattare sia le superfici apicali e basali. Inoltre, ricostruzione tridimensionale del citoscheletro actina alla superficie apicale dell&#39;epitelio dimostrato che lume intestinale è continua e che lumen secondarie sono un artefatto di sectioning. Questi due punti, insieme con la dimostrazione della migrazione nucleare interkinetic nell&#39;epitelio intestinale, definita l&#39;epitelio intestinale in via di sviluppo come un epitelio pseudostratificato e non stratificati come si pensava 1. La capacità di osservare l&#39;epitelio tridimensionale è stato seminale per dimostrare questo punto e ridefinendo morfogenesi epiteliale nell&#39;intestino del feto. Con l&#39;evoluzione della tecnologia di imaging multi-fotone e software di ricostruzione tridimensionale, la capacità di visualizzare intatto, lo sviluppo di organi sta rapidamente migliorando. Eccitazione a due fotoni permette la penetrazione meno dannoso più in profondità i tessuti con alta risoluzione. Due fotoni di imaging e la ricostruzione in 3D di tutto il fetali intestini del mouse in Walton et al., 2012 hanno contribuito a definire il modello di villi escrescenza 2. Qui si descrive un intero sistema di coltura d&#39;organo che permette ex vivo sviluppo dei villi e le estensioni di quel sistema di coltura per consentirel&#39;intestino ad essere tridimensionalmente ripreso durante il loro sviluppo.

Cultura di espianti interi di intestini fetali consente per le analisi del luogo, la distribuzione, e la durata delle molecole di segnalazione che coordinano lo sviluppo intestinale, in quanto questo sistema consente la manipolazione della segnalazione con reagenti farmacologici o proteine ​​ricombinanti. Il sistema di coltura transwell (Figura 1A, riprodotto da Walton et al., 2012) 2 fornisce una interfaccia aria-liquido, che permette di posizionare droga o proteine ​​imbevu...

Watch this Scientific Journal Video about Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development at JoVE.com

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Improved imaging technology is allowing three-dimensional imaging of organs during development. Here we describe a whole organ culture system that allows live imaging of the developing villi in the fetal mouse intestine.

Mouse fetale Whole Intestino Sistema Cultura per<em&gt; Ex Vivo</em&gt; La manipolazione delle vie di segnalazione e tridimensionale Imaging in diretta di Sviluppo del villo

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over ...

mouse-fetal-whole-intestine-culture-system-for-ex-vivo-manipulation

Research

JoVE Journal

Biology

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

14.8K Views.  University of Michigan. Improved imaging technology is allowing three-dimensional imaging of organs during development. Here we describe a whole organ culture system that allows live imaging of the developing villi in the fetal mouse intestine. 

Video: Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Method for Culture of Early Chick Embryos ex vivo (New Culture)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  the formation and patterning of brain, neural tube, somite and heart primordia. Applications of chick embryo culture include electroporation of DNA or RNA constructs in order to analyze gene function, grafts of growth factor coated beads such as FGFs and BMPs , as well as whole mount in situ hybridization and immunohistochemistry. This video demonstrates the different steps in chick embryo culture; First, the embryo is explanted in saline. Then, the embryo is centered on a glass ring. The membranes surrounding the embryo are lifted along the walls of the ring. The ring is then placed in a culture dish containing a pool of albumine. The culture dish is sealed and placed in a humid chamber, where the embryo is cultured for up to 24 hrs. Finally, the embryo is removed from the ring, fixed and processed for further applications. A troubleshooting guide is also presented.

Method for Culture of Early Chick Embryos ex vivo New Culture

This video demonstrates New culture, a method by which chick embryos are cultured outside the egg for up to 24 hr. This method enables one to study early development (primitive streak to 14 som.), a period corresponding to E7-9 in mouse. Applications of this technique include electroporation, in situ hybridization and immunohistochemistry.

Metodo per la Cultura di Chick primi embrioni ex vivo (Nuova Cultura)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Ricerca

Biologia

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

Imaging in vivo e trattamenti terapeutici in un modello di mouse ortotopico di cancro ovarico

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for discovering new therapeutic strategies. Advancements in imaging technology have enabled quantitative investigation of the organization and maturing of the body plan, but later stage embryonic morphogenesis is less clear. Chicken embryos are an attractive vertebrate animal model system for this application because of its ease of culture and surgical manipulation. Early embryos can be cultured for a short time on filter paper rings, which enables complete optical access for cell patterning and fate studies1,2. Studying advanced developmental processes such as cardiac morphogenesis are traditionally performed through a window of the eggshell3-5, but this technique limits optical access due to window size. We previously developed a simple method to culture whole embryos ex-ovo on hexagonal weigh boats for up to 10 days, which enabled high resolution imaging via ultrasonography6,7. These cultures were difficult to transport, limiting the types of imaging tools available for live experiments. We here present an improved shell-less culture system with a cost-effective, portable environmental chamber. Eggs were cracked onto a hammock created by a polyurethane membrane (cling wrap) affixed circumferentially to a plastic cup partially filled with sterile water. The dimensions of the circumference and depth of the hammock were both critical to maintain surface tension, while the mechanics of the hammock and water beneath helped dampen vibrations induced by transportation. A small footprint circulating water bath was also developed to enable continuous temperature control during experimentation. We demonstrate the ability to culture embryos in this way for at least 14 days without morphogenic defect or delay and employ this system in several microsurgical and imaging applications.

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.

Un Ex-ovo Sistema di embrioni di pollo Cultura Adatto per applicazioni di imaging e Microchirurgia

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for ...

The Method of Rodent Whole Embryo Culture using the Rotator-type Bottle Culture System

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development and growth of mammalian embryos are critically dependent on the function of the placenta, WEC technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages during embryonic day (E) 6.5-E12.5 in the mouse or E8.5-E14.5 in the rat 2, 3, 4. In WEC, we can directly target desired areas of embryos using fine glass capillaries because embryos can be manipulated under the microscope. Therefore, rodent WEC is very useful technique when we want to study dynamic developmental processes of postimplanted mammalian embryos. Up to date, several types of WEC systems have been developed 1. Among those, the rotator-type bottle culture system is most popular and suitable for long-term culture of embryos at midgestation, i.e., after E9.5 and E11.5 in the mouse and rat, respectively 1. In this video protocol, we demonstrate our standard procedures of rat WEC after E12.5 using a refined model of the original rotator system, which was designed by New and Cockroft 5, 6, and introduce various applications of WEC technique for studies in mammalian developmental biology.

Whole embryo culture technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages. In this video protocol, we demonstrate our standard procedures of rat whole embryo culture after E12.5 using the rotator-type bottle culture system.

Il metodo di coltura degli embrioni roditori intero utilizzando il Rotator tipo di sistema cultura Bottiglia

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development ...

A System for ex vivo Culturing of Embryonic Pancreas

The pancreas controls vital functions of our body, including the production of digestive enzymes and regulation of blood sugar levels1. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatic organogenesis, important gaps persist in our knowledge of early pancreas formation2. A complete understanding of these early events will provide insight into the development of this organ, but also into incurable diseases that target the pancreas, such as diabetes or pancreatic cancer. Finally, this information will generate a blueprint for developing cell-replacement therapies in the context of diabetes.
 During embryogenesis, the pancreas originates from distinct embryonic outgrowths of the dorsal and ventral foregut endoderm at embryonic day (E) 9.5 in the mouse embryo3,4. Both outgrowths evaginate into the surrounding mesenchyme as solid epithelial buds, which undergo proliferation, branching and differentiation to generate a fully mature organ2,5,6. Recent evidences have suggested that growth and differentiation of pancreatic cell lineages, including the insulin-producing &beta;-cells, depends on proper tissue-architecture, epithelial remodeling and cell positioning within the branching pancreatic epithelium7,8. However, how branching morphogenesis occurs and is coordinated with proliferation and differentiation in the pancreas is largely unknown. This is in part due to the fact that current knowledge about these developmental processes has relied almost exclusively on analysis of fixed specimens, while morphogenetic events are highly dynamic.
 Here, we report a method for dissecting and culturing mouse embryonic pancreatic buds ex vivo on glass bottom dishes, which allow direct visualization of the developing pancreas (Figure 1). This culture system is ideally devised for confocal laser scanning microscopy and, in particular, live-cell imaging. Pancreatic explants can be prepared not only from wild-type mouse embryos, but also from genetically engineered mouse strains (e.g. transgenic or knockout), allowing real-time studies of mutant phenotypes. Moreover, this ex vivo culture system is valuable to study the effects of chemical compounds on pancreatic development, enabling to obtain quantitative data about proliferation and growth, elongation, branching, tubulogenesis and differentiation. In conclusion, the development of an ex vivo pancreatic explant culture method combined with high-resolution imaging provides a strong platform for observing morphogenetic and differentiation events as they occur within the developing mouse embryo.

A System for ex vivo Culturing of Embryonic Pancreas

Here, we describe a method for isolation, culture and manipulation of mouse embryonic pancreas. This represents an excellent ex vivo system for studying various aspects of pancreatic development, including morphogenesis, differentiation and growth. Pancreatic bud explants can be cultured for several days and used in a range of different applications, including whole-mount immunofluorescence and live imaging.

Un sistema per<em&gt; Ex vivo</emColtura&gt; del pancreas embrionale

The pancreas controls vital functions of our body,  including the production of digestive enzymes and regulation of blood sugar  levels1. Although in the ...

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Double-strand breaks (DSBs) are the most deleterious DNA lesions a cell can encounter. If left unrepaired, DSBs harbor great potential to generate mutations and chromosomal aberrations1. To prevent this trauma from catalyzing genomic instability, it is crucial for cells to detect DSBs, activate the DNA damage response (DDR), and repair the DNA. When stimulated, the DDR works to preserve genomic integrity by triggering cell cycle arrest to allow for repair to take place or force the cell to undergo apoptosis. The predominant mechanisms of DSB repair occur through nonhomologous end-joining (NHEJ) and homologous recombination repair (HRR) (reviewed in2). There are many proteins whose activities must be precisely orchestrated for the DDR to function properly. Herein, we describe a method for 2- and 3-dimensional (D) visualization of one of these proteins, 53BP1.
The p53-binding protein 1 (53BP1) localizes to areas of DSBs by binding to modified histones3,4, forming foci within 5-15 minutes5. The histone modifications and recruitment of 53BP1 and other DDR proteins to DSB sites are believed to facilitate the structural rearrangement of chromatin around areas of damage and contribute to DNA repair6. Beyond direct participation in repair, additional roles have been described for 53BP1 in the DDR, such as regulating an intra-S checkpoint, a G2/M checkpoint, and activating downstream DDR proteins7-9. Recently, it was discovered that 53BP1 does not form foci in response to DNA damage induced during mitosis, instead waiting for cells to enter G1 before localizing to the vicinity of DSBs6. DDR proteins such as 53BP1 have been found to associate with mitotic structures (such as kinetochores) during the progression through mitosis10.
In this protocol we describe the use of 2- and 3-D live cell imaging to visualize the formation of 53BP1 foci in response to the DNA damaging agent camptothecin (CPT), as well as 53BP1's behavior during mitosis. Camptothecin is a topoisomerase I inhibitor that primarily causes DSBs during DNA replication. To accomplish this, we used a previously described 53BP1-mCherry fluorescent fusion protein construct consisting of a 53BP1 protein domain able to bind DSBs11. In addition, we used a histone H2B-GFP fluorescent fusion protein construct able to monitor chromatin dynamics throughout the cell cycle but in particular during mitosis12. Live cell imaging in multiple dimensions is an excellent tool to deepen our understanding of the function of DDR proteins in eukaryotic cells.

This protocol describes a method for visualizing a DNA double-strand break signaling protein activated in response to DNA damage as well as its localization during mitosis.

Due-e tridimensionale Live Cell Imaging di proteine ​​danno al DNA di risposta

Double-strand breaks (DSBs) are the most deleterious DNA lesions a cell can encounter. If left unrepaired, DSBs harbor great potential to generate ...

Mouse Embryonic Development in a Serum-free Whole Embryo Culture System

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in an oxygenated rolling bottle culture system. Mouse embryos at E10.5 were carefully isolated from the uterus with intact yolk sac and in a process involving precise surgical maneuver the embryos were gently exteriorized from the yolk sac while maintaining the vascular continuity of the embryo with the yolk sac. Compared to embryos prepared with intact yolk sac or with the yolk sac removed, these embryos exhibited superior survival rate and developmental progression when cultured under similar conditions. We show that these mouse embryos, when cultured in a defined medium in an atmosphere of 95% O2 / 5% CO2 in a rolling bottle culture apparatus at 37 &#176;&#8203;C for 16-40 hr, exhibit morphological growth and development comparable to the embryos developing in utero. We believe this method will be useful for investigators needing to utilize whole embryo culture to study signaling interactions important in embryonic organogenesis.

Serum utilized in embryo cultures contains unknown components that can affect the outcome of experiments especially in studies involving signaling interactions. Here we utilized a serum-free oxygenated culture system and show that mid-gestation mouse embryos cultured for 16-40 hr&#160;exhibit morphological development comparable to embryos developing in utero.

Embrionali di topo di sviluppo in un embrione di tutta la cultura di sistema privo di siero

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in ...

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts migrate through the epidermis of the embryo where they subsequently colonize the developing hair follicles1,2. Neural crest cell migration is extensively studied in vitro but in vivo methods are still not well developed, especially in mammalian systems. One alternative is to use ex vivo organotypic culture3-6. Culture of mouse embryonic skin requires the maintenance of an air-liquid interface (ALI) across the surface of the tissue3,6. High resolution live-imaging of mouse embryonic skin has been hampered by the lack of a good method that not only maintains this ALI but also allows the culture to be inverted and therefore compatible with short working distance objective lenses and most confocal microscopes. This article describes recent improvements to a method that uses a gas permeable membrane to overcome these problems and allow high-resolution confocal imaging of embryonic skin in ex vivo culture6. By using a melanoblast specific Cre-recombinase expressing mouse line combined with the R26YFPR reporter line we are able to fluorescently label the melanoblast population within these skin cultures. The technique allows live-imaging of melanoblasts and observation of their behavior and interactions with the tissue in which they develop. Representative results are included to demonstrate the capability to live-image 6&#160;cultures in parallel.

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

We describe the dissection and ex vivo culture of mouse embryonic skin. The culture system maintains an air-liquid interface across the tissue surface and allows imaging on an inverted microscope. Melanoblasts, a component of the developing skin, are fluorescently labeled allowing their behavior to be observed using confocal microscopy.

Ex vivo Cultura embrionali di topo della pelle e live-imaging delle Migrazioni Melanoblast

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts ...

An Ex vivo Culture System to Study Thyroid Development

The thyroid is a bilobated endocrine gland localized at the base of the neck, producing the thyroid hormones T3, T4, and calcitonin. T3 and T4 are produced by differentiated thyrocytes, organized in closed spheres called follicles, while calcitonin is synthesized by C-cells, interspersed in between the follicles and a dense network of blood capillaries. Although adult thyroid architecture and functions have been extensively described and studied, the formation of the &#8220;angio-follicular&#8221; units, the distribution of C-cells in the parenchyma and the paracrine communications between epithelial and endothelial cells is far from being understood.
This method describes the sequential steps of mouse embryonic thyroid anlagen dissection and its culture on semiporous filters or on microscopy plastic slides. Within a period of four days, this culture system faithfully recapitulates in vivo thyroid development. Indeed, (i) bilobation of the organ occurs (for e12.5 explants), (ii) thyrocytes precursors organize into follicles and polarize, (iii) thyrocytes and C-cells differentiate, and (iv) endothelial cells present in the microdissected tissue proliferate, migrate into the thyroid lobes, and closely associate with the epithelial cells, as they do in vivo.
Thyroid tissues can be obtained from wild type, knockout or fluorescent transgenic embryos. Moreover, explants culture can be manipulated by addition of inhibitors, blocking antibodies, growth factors, or even cells or conditioned medium. Ex vivo development can be analyzed in real-time, or at any time of the culture by immunostaining and RT-qPCR.
In conclusion, thyroid explant culture combined with downstream whole-mount or on sections imaging and gene expression profiling provides a powerful system for manipulating and studying morphogenetic and differentiation events of thyroid organogenesis.

An Ex vivo Culture System to Study Thyroid Development

This protocol describes dissection of mouse embryonic thyroid anlagen and the culture of explants on semiporous filters or on microscopy plastic slides. This system is ideal to study morphogenetic or differentiation events occurring during thyroid development of wild type or knockout embryos, and is amenable to gain- and loss-of-function experiments.

Un<em&gt; Ex vivo</em&gt; Cultura sistema per studiare lo sviluppo della tiroide

The thyroid is a bilobated endocrine gland localized at the base of the neck, producing the thyroid hormones T3, T4, and calcitonin. T3 and T4 are ...

FRET Imaging in Three-dimensional Hydrogels

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination.

F&#246;rster resonance energy transfer (FRET) imaging is a powerful tool for real-time cell biology studies. Here a method for FRET imaging cells in physiologic three-dimensional (3D) hydrogel microenvironments using conventional epifluorescence microscopy is presented. An analysis for ratiometric FRET probes that yields linear ratios over the activation range is described.

FRET Imaging in idrogel tridimensionali

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly ...