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.

NOTE: Toutes les souris ont été traitées avec humanité en utilisant des protocoles approuvés par l&#39;Université du Michigan Medical School Unité de médecine de laboratoire et les animaux selon les directives du Comité de l&#39;Université sur l&#39;utilisation et l&#39;entretien des animaux. 1 Tout le Système de culture d&#39;organes <ol><li> Préparation des milieux et des plaques de culture <ol><li> Dans une culture de tissu capot, enlevez 5 ml de BGJb médias de la bouteille de et ajouter 5 ml de Pen / Strep. Préparer un stock de travail des médias dans un tube conique de 50 ml, en ajoutant 1 ml de 5 mg / ml d&#39;acide ascorbique à 49 ml de BGJb médias (avec Pen / Strep). </li><li> Préparer une plaque de culture à 6 puits en ajoutant 1 ml de chacune des sous transwell. NOTE: Si les 6 transwell ne sont pas utilisés, déplacer transwell supplémentaires dans une plaque à 6 puits stérile frais pour une utilisation ultérieure. Ajouter 3 ml de travailler BGJb médias à chacune des trois boîtes de Pétri de 10 cm stériles. </li></ol></li><li> Préparation pour la dissection <ol><li> Faire tremper les outils de dissection dans 70% ethanol et être sûr de garder les outils propres tout en travaillant. </li><li> Mettre en place la zone de dissection avec un grand seau à glace et placer la plaque de culture à 6 puits et 10 cm boîtes de Pétri avec BGJb médias sur la glace. Travailler sur la glace autant que possible, tout en disséquant et la préparation des intestins de la culture. </li><li> Anesthésier les souris femelles adultes dans une chambre avec isofluorane (100 pi) avant l&#39;euthanasie par dislocation cervicale pour la récolte de l&#39;intestin du foetus. </li><li> Après la récolte, les fœtus de leur mère, en scène chaque fœtus soigneusement selon le tableau 13 Theiler mise en scène. Ne vous fiez pas aux jours post-coït pour déterminer l&#39;âge de chaque fœtus comme des variations allant jusqu&#39;à 24 heures dans le stade de développement sont régulièrement observés dans une seule portée. </li></ol></li><li> Dissection de l&#39;intestin du foetus <ol><li> Euthanasier fœtus par décapitation avant le retrait de l&#39;intestin. </li><li> Disséquer chaque intestin en tampon phosphate salin (DPBS) de 1x Dulbecco puis plaCE dans une boîte de Pétri de 10 cm de travailler BGJb médias. </li><li> Retirez délicatement la rate de l&#39;estomac et le pancréas de l&#39;estomac et du duodénum supérieur. </li><li> Séparez délicatement l&#39;épiploon prenant soin de laisser l&#39;épiploon attachée autant que possible et en séparant seulement assez de connexions pour permettre à l&#39;intestin pour être redressé. NOTE: Pour les intestins plus que E14.5 ou ceux qui sont mis en culture pendant plus de 24 heures, séparer délicatement l&#39;intestin en 3 segments égaux pour permettre contenu luminal de couler à travers l&#39;intestin et être expulsés des extrémités coupées. Toutefois, pour les cultures commencé avant E13.5, attendre après 24 heures de culture avant de se séparer les 3 segments de l&#39;intestin pour permettre la séreuse de croître correctement sur toute la longueur de l&#39;intestin. </li><li> Utilisez une pipette de bouche pour transférer les morceaux intestinales sur les transwell de la plaque de culture (1.1.2). </li><li> Repositionner délicatement les intestins au besoin afin qu&#39;ils soient directement à travers la transwell. NOTE: Une fois que les intestins commencent à s&#39;installer contenu luminal dans le tube, les plier dans l&#39;intestin entraînera une sauvegarde et des dommages à l&#39;intestin. </li></ol></li><li> Culture et le traitement <ol><li> Retirez le support sous le transwell, ajouter 700 ul de milieu de traitement (médias travaillent avec des protéines recombinantes ajoutés ou des inhibiteurs pharmacologiques) dans le cadre du transwell. </li><li> Ajouter 300 ul de milieu de traitement goutte à goutte sur le dessus de l&#39;intestin et laisser tremper à travers le transwell. Repositionner les intestins comme nécessaire. </li><li> Changer agents de traitement au moins une fois par jour ou plus souvent fonction de la demi-vie du réactif de traitement. </li></ol></li><li> Préparation de protéine des billes d&#39;agarose imprégné d&#39;une source localisée de réactif de traitement <ol><li> Remettre en suspension les billes d&#39;agarose dans leur conteneur de stockage et transférer 100 pl de billes d&#39;agarose dans un tube à centrifuger de 1,5 ml. </li><li> Remplir le volume restant du tube avec 1x stérile Phosphate solution saline tamponnée (PBS) et mélanger les perles pour les laver. Placez le tube de centrifugeuse dans un rack pendant quelques minutes pour permettre aux billes de se déposent au fond et puis pipette au large de la PBS à partir au-dessus des perles. Remplir le tube de centrifugeuse stérile de PBS 1x et répéter deux fois plus le processus de lavage. </li><li> Préparation de la protéine d&#39;intérêt à deux fois la concentration désirée pour le traitement. </li><li> Mélanger 5 pi de billes d&#39;agarose lavés avec 5 pi de la protéine actions 2x et agiter doucement les perles dans la protéine. Placer le tube sur la glace pendant 1 heure, en mélangeant délicatement toutes les 10-15 min. </li><li> Rincer les perles brièvement stérile 1x PBS avant de placer les perles sur les intestins. </li></ol></li><li> Placement des billes d&#39;agarose <ol><li> Placez délicatement les billes d&#39;agarose sur le dessus de l&#39;intestin à l&#39;aide d&#39;une pipette de bouche avec des aiguilles capillaires tirés. Placez les perles avec une extrême prudence, car une manipulation brutale peut endommager l&#39;intestin et prévenir le développement des villosités dans la zone lésée. </li><li> Placez deux fois plus de billes que nécessaire pour l&#39;analyse depuis les intestins vont subir les mouvements péristaltiques et environ la moitié des billes placées roulera hors de l&#39;intestin au cours de la durée de la culture. </li></ol></li><li> Fixation des intestins culture <ol><li> Retirez délicatement les médias de traitement de dessous de la transwell et permettre aux intestins sécher à l&#39;air pendant 3 min. </li><li> Ajouter 1 ml de fixatif sous la Transwell pendant 2 min, puis recouvrir la partie supérieure de l&#39;intestin avec 2 ml de fixatif pour le reste de la période de fixation. Fixer avec 4% de paraformaldéhyde O / N à 4 ° C ou pendant 2 heures à température ambiante. </li></ol></li></ol> 2. imagerie de l&#39;intestin fixes <ol><li> Imagerie Wholemount <ol><li> Placez les intestins entiers (avec fluorescence endogène) sur une diapositive avec 100 pi de 1x DPBS. Utilisez une pince à organiser doucement les intestins. </li><li> Utilisez un tissu de laboratoire pour retirer soigneusement les DPBS et ajouter immédiatement 100 pi de 70% de glycérol à faire la mo tissure transparente et augmenter la profondeur possible de l&#39;imagerie. REMARQUE: Si une plus grande pénétration de l&#39;intestin est souhaité, au lieu de monter l&#39;intestin dans 70% de glycérol, tremper l&#39;intestin dans quelques gouttes d&#39;orientation claire solution pour 10-30 min. Pipeter au large de la solution mise au point claire et monter l&#39;intestin avec le Mont Effacer. </li><li> Tremper chaque des quatre coins d&#39;une lamelle en pâte à modeler et ramasser une petite quantité d&#39;argile à utiliser comme entretoises entre la lame et lamelle pour maintenir la lamelle de l&#39;aplatissement de l&#39;intestin. </li><li> Sceller la lamelle sur la lame avec valap fondu appliquée avec un coton-tige. </li><li> L&#39;image sur les intestins soit un microscope confocal debout ou inversé. S&#39;il vous plaît se référer à la discussion pour plus de détails. </li></ol></li><li> Vibratome sectionnement de l&#39;intestin fixes (pour une vue en coupe transversale de structures intestinales) <ol><li> Intégrer dans les intestins 7% d&#39;agarose dans de petits moules en plastique (10 x 10 x 15 mm) et permettre aux blocs d&#39;agarose àrefroidir et se solidifier. </li><li> Retirer des blocs d&#39;agarose à partir de moules en plastique et des blocs d&#39;agarose colle à l&#39;étape de collecte de vibratome avec de la colle instantanée. </li><li> Remplir le stade de la collecte de froid de glace 1x DPBS. </li><li> Couper des sections à une épaisseur comprise entre 100-150 um. Pour les sections plus épaisses utilisent les solutions de compensation (décrits dans la section 2.1.2) pour visualiser plus profondément dans la section. </li><li> Verser vibratome sections de l&#39;étape de la collecte dans un puits d&#39;une plaque à 6 puits pour le stockage à 4 ° C. </li></ol></li><li> Immunofluorescence, de tissus vibratome sectionnés fixes <ol><li> Placez 5-12 sections vibratome par puits dans une plaque de 24 puits avec 1x DPBS. </li><li> Retirer 1x DPBS et ajouter 500 ul de solution de perméabilisation par puits. Secouez délicatement les échantillons pendant 25 min à température ambiante. </li><li> Après perméabilisation, laver les échantillons 3 fois avec du PBS 1X. </li><li> Bloquer les échantillons pendant au moins 30 min dans 500 pi de solution de blocage. </li><li> Après blocage, eXCHANGE la solution de blocage avec 500 ul d&#39;anticorps primaire dilué dans la solution de blocage et conserver les échantillons à 4 ° CO / N. REMARQUE: Les dilutions d&#39;anticorps primaires qui fonctionnent bien sur des coupes congelées et paraffine fonctionnent généralement bien sur vibratome sections aussi, cependant anticorps nécessitant l&#39;extraction de l&#39;antigène nucléaire en général ne fonctionnent pas bien avec ce protocole (par exemple, BrdU). </li><li> Le jour suivant, laver les échantillons 3 fois pendant 15 min à chaque fois avec une solution de blocage. </li><li> Après lavage, 500 ul d&#39;appliquer l&#39;anticorps secondaire dilué dans une solution de blocage. Enveloppez la plaque de 24 puits dans du papier d&#39;aluminium pour protéger les fluorophores de la lumière et de la roche les échantillons pendant 45 minutes à 2 heures à température ambiante. </li><li> Laver les échantillons 3 fois avec du PBS 1X pendant 15 minutes chacun et monter les sections de vibratome sur des lames comme décrit à la section 2.4. </li></ol></li><li> Montage sections vibratome <ol><li> Préparer des lames pour vibratome de montage par couper de fines tranches de double-stick bande et en les plaçant sur les côtés longs des lamelles. </li><li> Placez délicatement 5-10 sections vibratome entre le ruban adhésif double-bâton sur les lames dans une goutte de 100 pi de PBS 1x. </li><li> Déplier toutes les sections et les étaler en une seule couche sur la diapositive. </li><li> Retirez tout excès d&#39;agarose ou des morceaux inégaux qui empêcherait une lamelle de siéger plat. </li><li> Soigneusement utiliser un tissu de laboratoire pour absorber l&#39;excès de PBS 1x autour des sections de vibratome. </li><li> Ajouter une goutte de milieu de montage aqueux sur des sections de vibratome et lamelle. </li><li> Sceller les lamelles sur les lames avec fondu valap appliquée avec un coton-tige. </li><li> Image, les sections de vibratome sur soit un microscope confocal droit ou inversé. S&#39;il vous plaît se référer à la discussion pour plus de détails sur la sélection d&#39;un système d&#39;imagerie. </li></ol></li></ol> 3. imagerie en direct de l&#39;intestin entiers Intestins récolté de fetuses après E12.5, avec l&#39;épiploon connecté laissée intacte, développer avec succès villosités en culture en utilisant le système ci-dessus. Par conséquent, ce système ex vivo permet la capture d&#39;images en direct z-section de l&#39;intestin de développement qui peut être reconstituée pour une vue en trois dimensions de la morphogenèse au cours du temps. <ol><li> Mise en place d&#39;imagerie en temps réel <ol><li> Utilisez de la colle instantanée à respecter une membrane de polycarbonate individu à un tamis à mailles fines. Cela fournit un échafaudage de support pour maintenir l&#39;intestin en place sous l&#39;objectif de trempage du microscope confocal verticale. S&#39;il vous plaît se référer à la section de discussion pour plus de détails sur la sélection de microscopes d&#39;imagerie en direct. </li><li> Placer le tamis dans le puits central d&#39;une plaque de culture. </li><li> Placer l&#39;intestin disséqué sur la membrane de polycarbonate et on ajoute une goutte de colle instantanée à chaque extrémité. Utilisez seulement assez de colle pour fixer l&#39;intestin, mais pas l&#39;enduire! </li><li> Ajouter culture libre de médias de phénol rouge ci-dessous le polycarbonatemembrane dans le puits central de la plaque de culture. </li><li> Ajouter de l&#39;eau à la bordure extérieure de la plaque de culture à fournir de l&#39;humidité. </li><li> Depuis l&#39;intestin foetal subit ondes péristaltiques analogues de contraction dans la culture, ajouter 100 ul d&#39;une solution 1: 5 de xylazine dans du PBS 1x à 3 ml de milieu à contrôler les mouvements de l&#39;intestin, tandis que l&#39;imagerie. Cette posologie sera de contrôler les mouvements intestinaux pour environ 8-10 heures sans compromettre le développement des villosités. </li><li> Pour une vue transversale de l&#39;intestin, intégrer les intestins vivants dans une solution d&#39;agarose à 3-4% et couper des sections épaisses (150-500 de um) sur un vibratome. Correspondre à la rigidité de l&#39;agarose avec la rigidité de l&#39;intestin étant déterminée empiriquement et couper le stade de développement. En général, une solution d&#39;agarose à 3% fonctionne bien pour les intestins de moins de E14.5 et une solution à 4% fonctionne bien pour les intestins E15-E16. </li><li> Coller les sections de vibratome à une membrane de polycarbonate, apposée sur un tamis à mailles (comme dans la section 3.1.1) etculture comme décrit dans la Section 3.1.2-3.1.6. </li><li> Effectuer l&#39;imagerie en temps réel en utilisant un microscope confocal à fluorescence à deux photons (laser d&#39;excitation entre 690-1,040 nm) sur un support vertical avec une table réglable. </li><li> Laser à deux photons réglé à 900 nm permet une pénétration profonde avec la meilleure résolution pour les signaux de GFP. Il réduit les dommages aux tissus en imagerie. En outre, le réglage de la puissance du laser pour l&#39;émission le plus bas possible pour réduire les dommages des tissus. En général pour obtenir une bonne excitation de la GFP, en utilisant 12% de la puissance du laser à deux photons. </li></ol></li></ol>

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The authors have no financial conflicts to disclose.

La nature dynamique et les interactions de tissus complexes de l&#39;intestin en développement exige une visualisation 3D d&#39;avoir une appréciation complète de ces événements morphogénétiques. Avec l&#39;évolution des technologies d&#39;imagerie, la capacité d&#39;examiner en détail la morphogenèse des villosités se développe / amélioration et, avec elle, la compréhension de la communication spatiale et interaction pendant l&#39;organogenèse est grandement améliorée. Des...

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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			<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 plupart des processus morphogénétiques dans l&#39;intestin du foetus ont été déduites à partir des coupes minces de tissus fixés, présenter des instantanés de changements au cours des stades de développement. Des informations en trois dimensions à partir de coupes sériées minces peut être difficile à interpréter en raison de la difficulté de reconstituer des coupes en série et parfaitement maintenir l&#39;orientation correcte du tissu sur coupes sériées. Les études récentes de Grosse et al., 2011 soulignent l&#39;importance des trois dimensions informations pour comprendre la morphogenèse des villosités de l&#39;intestin en développement 1. Reconstruction tridimensionnelle de cellules intestinales individuellement marqués ont démontré que la majorité des cellules épithéliales de l&#39;intestin contact avec les deux surfaces apicales et basales. En outre, la reconstruction en trois dimensions du cytosquelette d&#39;actine à la surface apicale de l&#39;épithélium a démontré que la lumière intestinale est continue et que les lumières secondaires sont un artefact de sectioning. Ces deux points, ainsi que la démonstration de la migration nucléaire interkinetic dans l&#39;épithélium intestinal, définis l&#39;épithélium intestinal en développement un épithélium pseudo et non stratifiées comme le pensait auparavant 1. La capacité d&#39;observer l&#39;épithélium en trois dimensions a été décisif pour démontrer ce point et la redéfinition de la morphogenèse épithéliale dans l&#39;intestin du foetus. Avec l&#39;évolution des technologies d&#39;imagerie multi-photonique et logiciel de reconstruction tridimensionnelle, la capacité de visualiser intact, le développement des organes s&#39;améliore rapidement. Excitation à deux photons permet une pénétration moins dommageable plus profondément dans les tissus à haute résolution. Imagerie à deux photons et la reconstruction 3D de l&#39;ensemble des intestins de souris fœtales à Walton et al., 2012 ont contribué à définir le modèle de villosités excroissance 2. Nous décrivons ici un ensemble de système de culture d&#39;organe qui permet le développement ex vivo de villosités et extensions de ce système de culture pour permettreles intestins pour être en trois dimensions imagé au cours de leur développement.

Culture des explants entiers de l&#39;intestin fœtal permet l&#39;analyse de la localisation, la distribution, et la durée des molécules de signalisation qui coordonnent le développement intestinal, comme ce système permet la manipulation de la signalisation avec des réactifs pharmacologiques ou des protéines recombinantes. Le système de culture Transwell (Figure 1A, reproduit à partir de Walton et al., 2012) 2 fournit une interface air-liquide, ce qui permet de placer la dr...

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.

Souris foetal entier Intestin Système de culture pour<em&gt; Ex Vivo</em&gt; Manipulation des voies de signalisation et d&#39;imagerie en direct en trois dimensions du développement des villosités

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 vues.  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. 

Vidéo: 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.

Méthode pour la culture d&#39;embryons de poulet Early ex vivo (Nouvelle 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 ...

Recherche

Biologie

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.

L&#39;imagerie in vivo et des traitements thérapeutiques dans un modèle de souris orthotopique de cancer des ovaires

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.

Une Ex-ovo- Poulet embryonnaire du système de culture approprié pour les applications d&#39;imagerie et de microchirurgie

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.

La méthode de culture des embryons rongeurs entier en utilisant le système des rotateurs de type flacon de culture

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 système d&#39;<em&gt; Ex vivo</emLa culture&gt; de pancréas embryonnaire

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.

Deux et trois dimensions imagerie de cellules vivantes de protéines endommagent l&#39;ADN de réponse

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.

Souris développement embryonnaire dans tout un système de culture d&#39;embryons sans sérum

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 Culture de la peau de souris embryonnaires et Live-imagerie de la migration mélanoblaste

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; Système de culture à étudier la thyroïde développement

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 en hydrogels en trois dimensions

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 ...