Questo lavoro è stato finanziato dalla R01-R01-DE018234 e DE019638.

1. Preparazione del tessuto del donatore <ol><li> Preparare terreni di coltura, affinare le spine di vetro, affilare gli aghi di tungsteno. </li><li> Raccogliere embrione dal guscio, lavare in gelide PBS. <ol class="lalpha"><li> Usando una siringa da 10 ml e 18 gauge rimuovere 1,0 ml di albumina da l&#39;estremità appuntita del guscio d&#39;uovo. </li><li> Fai un piccolo foro sulla parte superiore del guscio utilizzando il punto di forbici, e poi tagliare un&#39;apertura circolare per esporre l&#39;embrione </li></ol></li><li> Togliere la testa e il luogo in DMEM (siero libero, temperatura ambiente) </li><li> Sezionare processo fronto-nasale dall&#39;embrione (o sito altri donatori, come processo mascellare o mandibolare) </li><li> Digest in 2.4U / mL dispasi in PBS in ghiaccio per 20 minuti </li><li> Coprire i tessuti con DMEM con BSA 1% per fermare la digestione </li><li> Utilizzare l&#39;ago di tungsteno appuntito per ectoderma separati, mesenchima, e neuroectoderma </li><li> Conservare il tessuto innesto in DMEM BSA 1% in ghiaccio fino host è pronto per i trapianti </li></ol> 2. Preparare l&#39;Ostia <ol><li> Esporre l&#39;embrione <ol class="lalpha"><li> Usando una siringa da 10 ml e 18 gauge rimuovere 1,0 ml di albumina da l&#39;estremità appuntita del guscio d&#39;uovo. </li><li> Fai un piccolo foro sulla parte superiore del guscio utilizzando il punto di forbici. Posizionare un pezzo di nastro adesivo sul foro, e poi tagliare un&#39;apertura circolare per esporre l&#39;embrione. </li></ol></li><li> Con 2 coppie di pinze, afferrare la amnios e delicatamente strappare a fare un buco. </li><li> Ruotare la testa mettendo una coppia di pinze sull&#39;occhio destro e pressione. Tenendo la testa ferma, utilizzare un ago di tungsteno per rimuovere l&#39;ectoderma ospitare per accogliere l&#39;innesto. </li><li> Trasferire l&#39;innesto per l&#39;host utilizzando una pipetta di vetro. </li><li> Posizionare l&#39;innesto di sostituire l&#39;ectoderma rimosso. Inserire un perno di vetro in ogni angolo del tessuto innestato al pin l&#39;innesto in posizione. Per rendere pin vetro, tirare un tubo microcapillare ad un punto preciso su una fiamma alcol. </li><li> Luogo nastro saldamente sopra il buco e tornare embrione per l&#39;incubatore per la lunghezza di tempo adeguato per l&#39;analisi. </li><li> vedi anche: 9 </li></ol> 3. Rappresentante dei risultati: Per valutare chimere, gli embrioni devono essere raccolti ed elaborati per l&#39;analisi della distribuzione di host e dei tessuti del donatore. Per il rilevamento di cellule quaglia, immunoistochimica con l&#39;anticorpo QcPN (descritto in: 3) è impiegata, e per l&#39;individuazione di cellule di topo, ibridazione in situ su sezioni di paraffina viene utilizzata 6. Cellule del donatore deve essere limitato al epitelio, e ci dovrebbe essere alcuna prova donatore di tessuti mesenchimali (Figura 1). La presenza di cellule del donatore isolate nel mesenchima indica la presenza di contaminazione da cellule della cresta neurale, che si confondono ogni interpretazione morfologica per l&#39;influenza di queste cellule in molti aspetti dello sviluppo del viso (per esempio, 10). Una volta convinto che la tecnica dell&#39;innesto è libero di contaminare mesenchima, misure di ulteriore esito morfologico o molecolare può essere utilizzata per valutare le chimere. Per i nostri scopi, abbiamo rilevato la presenza di cartilagini e ossa ectopica che corrispondevano a duplicazioni della mascella superiore, che sono state indotte dai tessuti trapiantati (Figura 2), e cambiamenti molecolari nei tessuti mesenchimali in risposta alla ectoderma innestati (Figura 3) 5,6. <img src="/files/ftp_upload/2557/2557fig1.jpg" alt="Figura 1" /> Figura 1. Valutazione del chimerismo (A) Anti-QcPN colorazione è usato per rilevare le cellule di quaglia quaglia-chick chimere. Non ci sono prove di colorazione nel mesenchima. (B) L&#39;ibridazione in situ è utilizzato per rilevare l&#39;espressione di trascrizioni B2 SINE nel topo-chick chimere. Espressione è limitata alla ectoderma che comprende l&#39;innesto. <img src="/files/ftp_upload/2557/2557fig2.jpg" alt="Figura 2" /> Colorazione Figura 2. Tricromica mostra duplicazione dello scheletro mascellare superiore in (A) quaglia-chick chimera, e (B) topo-chick chimere. <img src="/files/ftp_upload/2557/2557fig3.jpg" alt="Figura 3" /> Figura 3. L&#39;ectoderma regultes espressione genica nel mesenchima. (A) Normale Bmp7 espressione nel mesenchima di un embrione di pollo (radioattive ibridazione in situ con positivo segnale pseudo-colore rosso in Adobe Photoshop). (B) Bmp7 espressione è indotta nel mesenchima adiacente al trapianto (Freccia) in embrioni chimerici.

<ol>
	<li>Noden, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Role+of+the+Neural+Crest+in+Patterning+of+Avian+Cranial+Skeletal,+Connective,+and+Muscle+Tissues.">The Role of the Neural Crest in Patterning of Avian Cranial Skeletal, Connective, and Muscle Tissues.</a> Developmental Biology. 96, 144-144 (1983).</li><li>Bronner-Fraser, M., Stern, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+Mesodermal+Tissues+on+Avian+Neural+Crest+Cell+Migration.">Effects of Mesodermal Tissues on Avian Neural Crest Cell Migration.</a> Developmental Biology. 143, 213-213 (1991).</li><li>Schneider, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+crest+can+form+cartilages+normally+derived+from+mesoderm+during+development+of+the+avian+head+skeleton.">Neural crest can form cartilages normally derived from mesoderm during development of the avian head skeleton.</a> Developmental Biology. 208, 441-441 (1999).</li><li>Couly, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactions+between+Hox-negative+cephalic+neural+crest+cells+and+the+foregut+endoderm+in+patterning+the+facial+skeleton+in+the+vertebrate+head.">Interactions between Hox-negative cephalic neural crest cells and the foregut endoderm in patterning the facial skeleton in the vertebrate head.</a> Development. 129, 1061-1061 (2002).</li><li>Evans, D. J., Noden, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+relations+between+avian+craniofacial+neural+crest+and+paraxial+mesoderm+cells.">Spatial relations between avian craniofacial neural crest and paraxial mesoderm cells.</a> Dev Dyn. , (2006).</li><li>Hu, D., Marcucio, R., Helms, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+zone+of+frontonasal+ectoderm+regulates+patterning+and+growth+in+the+face.">A zone of frontonasal ectoderm regulates patterning and growth in the face.</a> Development. 130, 1749-1749 (2003).</li><li>Hu, D., Marcucio, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unique+organization+of+the+frontonasal+ectodermal+zone+in+birds+and+mammals.">Unique organization of the frontonasal ectodermal zone in birds and mammals.</a> Dev Biol. 325, 200-200 (2009).</li><li>Le Li&#232;vre, C. S., Le Douarin, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+derivatives+of+the+neural+crest:+analysis+of+chimaeric+quail+and+chick+embryos.">Mesenchymal derivatives of the neural crest: analysis of chimaeric quail and chick embryos.</a> Journal of Embryology and Experimental Morphology. 34, 125-125 (1975).</li><li>Bollag, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+repetitive+mouse+B2+element+to+identify+transplanted+mouse+cells+in+mouse-chick+chimeras.">Use of a repetitive mouse B2 element to identify transplanted mouse cells in mouse-chick chimeras.</a> Exp Cell Res. 248, 75-75 (1999).</li><li>Korn, M. J., Cramer, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Windowing+chicken+eggs+for+developmental+studies.">Windowing chicken eggs for developmental studies.</a> J Vis Exp. , (2007).</li><li>Eames, B. F., Schneider, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quail-duck+chimeras+reveal+spatiotemporal+plasticity+in+molecular+and+histogenic+programs+of+cranial+feather+development.">Quail-duck chimeras reveal spatiotemporal plasticity in molecular and histogenic programs of cranial feather development.</a> Development. 132, 1499-1499 (2005).</li><li>Odent, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+Sonic+hedgehog+(SHH+)+gene+during+early+human+development+and+phenotypic+expression+of+new+mutations+causing+holoprosencephaly.">Expression of the Sonic hedgehog (SHH ) gene during early human development and phenotypic expression of new mutations causing holoprosencephaly.</a> Hum Mol Genet. 8, 1683-1683 (1999).</li><li>Szabo-Rogers, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+skeletogenic+patterning+roles+for+the+olfactory+pit.">Novel skeletogenic patterning roles for the olfactory pit.</a> Development. 136, 219-219 (2009).</li></ol>

Nessun conflitto di interessi dichiarati.

Usando questo metodo di trapianto ha permesso di determinare che l&#39;ectoderma contiene informazioni di segnalazione che regola la polarità dorso-ventrale e l&#39;estensione prossimo-distale della mascella superiore. La somiglianza dei risultati quando si usa quaglia o ectoderma mouse e la conservazione dei segnali molecolari in questo tessuto tra le molte specie 6,11 indica che questo è un centro altamente conservato di segnalazione tra i vertebrati. Inoltre, altri ricercatori hanno usato tecniche simili...

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<td>1x PBS</td>
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<td>DMEM</td>
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<td>&nbsp;</td>
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<td>Fine Science Tools</td>
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<td>Razor blade</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
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assessing signaling properties of ectodermal epithelia during craniofacial development

L&#39;accessibilità degli embrioni aviaria ha aiutato embriologi sperimentali capire il destino delle cellule durante lo sviluppo e il ruolo delle interazioni tessuti che regolano patterning e la morfogenesi dei vertebrati (ad esempio, 1, 2, 3, 4). Qui, illustrare un metodo che sfrutta questa accessibilità per testare la segnalazione e le proprietà patterning dei tessuti durante lo sviluppo ectodermica del viso. In questi esperimenti, creiamo quaglia-chick 5 o topo-chick 6 chimere trapiantando l&#39;ectoderma cefalico superficie che copre la mascella superiore da quaglia o mouse sulla entrambi della stessa regione o di una regione ectopica di embrioni di pollo. L&#39;uso di quaglia come tessuto del donatore per il trapianto in pulcini è stato sviluppato per trarre vantaggio da un marker nucleolare presente in quaglie, ma non le cellule pulcino, permettendo così agli investigatori di distinguere host e tessuti del donatore 7. Allo stesso modo, un elemento ripetitivo è presente nel genoma del topo ed è espressa ubiquitariamente, che ci permette di distinguere host e tessuti del donatore nel topo-chick chimere 8. L&#39;uso di ectoderma mouse come tessuto del donatore amplieranno enormemente la nostra comprensione di queste interazioni dei tessuti, perché questo ci permetterà di testare le proprietà di segnalazione di ectoderma derivate da embrioni mutanti vari.

Watch this Scientific Journal Video about Assessing Signaling Properties of Ectodermal Epithelia During Craniofacial Development at JoVE.com

Assessing Signaling Properties of Ectodermal Epithelia During Craniofacial Development

Questo articolo descrive una tecnica di trapianto di tessuto che è stato progettato per verificare la segnalazione e le proprietà di patterning ectoderma cefalico superficie durante lo sviluppo cranio-facciale.

La valutazione delle proprietà di segnalazione di ectodermica epiteli durante lo sviluppo craniofacciale

The accessibility of avian embryos has helped experimental embryologists understand the fates of cells during development and the role of tissue ...

assessing-signaling-properties-ectodermal-epithelia-during

Research

JoVE Journal

Biology

9.4K Views.  University of California San Francisco. Questo articolo descrive una tecnica di trapianto di tessuto che è stato progettato per verificare la segnalazione e le proprietà di patterning ectoderma cefalico superficie durante lo sviluppo cranio-facciale.

Video: Assessing Signaling Properties of Ectodermal Epithelia During Craniofacial Development

Electroporation of Craniofacial Mesenchyme

Electroporation is an efficient method of delivering DNA and other charged macromolecules into tissues at precise time points and in precise locations. For example, electroporation has been used with great success to study neural and retinal development in Xenopus, chicken and mouse 1-10. However, it is important to note that in all of these studies, investigators were not targeting soft tissues. Because we are interested in craniofacial development, we adapted a method to target facial mesenchyme.
When we searched the literature, we found, to our surprise, very few reports of successful gene transfer into cartilaginous tissue. The majority of these studies were gene therapy studies, such as siRNA or protein delivery into chondrogenic cell lines, or, animal models of arthritis 11-13. In other systems, such as chicken or mouse, electroporation of facial mesenchyme has been challenging (personal communications, Dept of Craniofacial Development, KCL). We hypothesized that electroporation into procartilaginous and cartilaginous tissues in Xenopus might work better. In our studies, we show that gene transfer into the facial cartilages occurs efficiently at early stages (28), when the facial primordium is still comprised of soft tissue prior to cartilage differentiation.
Xenopus is a very accessible vertebrate system for analysis of craniofacial development. Craniofacial structures are more readily visible in Xenopus than in any other vertebrate model, primarily because Xenopus embryos are fertilized externally, allowing analyses of the earliest stages, and facilitating live imaging at single cell resolution, as well as reuse of the mothers 14. Among vertebrate models developing externally, Xenopus is more useful for craniofacial analysis than zebrafish, as Xenopus larvae are larger and easier to dissect, and the developing facial region is more accessible to imaging than the equivalent region in fish. In addition, Xenopus is evolutionarily closer to humans than zebrafish (&tilde;100 million years closer) 15. Finally, at these stages, Xenopus tadpoles are transparent, and concurrent expression of fluorescent proteins or molecules will allow easy visualization of the developing cartilages. We anticipate that this approach will allow us to rapidly and efficiently test candidate molecules in an in vivo model system.

Craniofacial cartilages develop in close contact with other tissues and are difficult to manipulate in live animals. We are using electroporation to deliver molecular tools during growth of the craniofacial skeleton while bypassing early embryonic effects. This approach will allow us to efficiently test candidate molecules in vivo.

Elettroporazione di Mesenchima craniofacciale

Electroporation is an efficient method of delivering DNA and other charged macromolecules into tissues at precise time points and in precise locations. ...

Ricerca

Biologia

Rapid Genetic Analysis of Epithelial-Mesenchymal Signaling During Hair Regeneration

Hair follicle morphogenesis, a complex process requiring interaction between epithelia-derived keratinocytes and the underlying mesenchyme, is an attractive model system to study organ development and tissue-specific signaling. Although hair follicle development is genetically tractable, fast and reproducible analysis of factors essential for this process remains a challenge. Here we describe a procedure to generate targeted overexpression or shRNA-mediated knockdown of factors using lentivirus in a tissue-specific manner. Using a modified version of a hair regeneration model 5, 6, 11, we can achieve robust gain- or loss-of-function analysis in primary mouse keratinocytes or dermal cells to facilitate study of epithelial-mesenchymal signaling pathways that lead to hair follicle morphogenesis. We describe how to isolate fresh primary mouse keratinocytes and dermal cells, which contain dermal papilla cells and their precursors, deliver lentivirus containing either shRNA or cDNA to one of the cell populations, and combine the cells to generate fully formed hair follicles on the backs of nude mice. This approach allows analysis of tissue-specific factors required to generate hair follicles within three weeks and provides a fast and convenient companion to existing genetic models.

Tissue-specific analysis of a hair follicle regeneration model using lentivirus to mediate gain- or loss-of-function.

Rapida analisi genetica di epitelio-mesenchimale segnalazione durante la rigenerazione dei capelli

Hair follicle morphogenesis, a complex process requiring interaction between epithelia-derived keratinocytes and the underlying mesenchyme, is an ...

Cell Tracking Using Photoconvertible Proteins During Zebrafish Development

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of genetically-encoded fluorescent proteins has proven a valuable strategy for elucidating dynamic morphogenetic processes as they occur in the intact organism. During the past decade, the development of photoactivatable and photoconvertible fluorescent proteins has opened the possibility to investigate the fate of discrete subpopulations of tagged proteins1. Unlike photoactivatable proteins, photoconvertible fluorescent proteins (PCFPs) are readily tracked and imaged in their native emission state prior to photoconversion, making it easier to identify and select regions by optical inspection. PCFPs, such as Kaede2, KikGR3, Dendra4 and EosFP5, can be shifted from green to red upon exposure to UV or blue light due to a His-Tyr-Gly tripeptide sequence which forms a green chromophore that can be photoconverted to a red one by a light-catalyzed &beta;-elimination and subsequent extension of a &pi;-conjugated system3. PCFPs and their monomeric variants are useful tools for tracking cells6-10 and studying protein dynamics11-14, respectively. During recent years, PCFPs have been expressed in different animal model, such as zebrafish6, chicken7,8 and mouse9,10 for cell fate tracking. Here we report a protocol for cell-specific photoconversion of PCFPs in the living zebrafish embryo and further tracking of photoconverted proteins at later developmental stages. This methodology allows studying, in a tissue-specific manner, cell biological events underlying morphogenesis in the zebrafish animal model.

Here, we present a method for the photoactivated switch of photoconvertible fluorescent proteins (PCFPs) in the living zebrafish embryo and further tracking of photoconverted protein at specific time points during development. This methodology allows monitoring of cell biological events underlying different developmental processes in a live vertebrate organism.

Cella di rilevamento utilizzando proteine ​​Photoconvertible durante lo sviluppo Zebrafish

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of ...

Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development

Fate maps, constructed from lineage tracing all of the cells of an embryo, reveal which tissues descend from each cell of the embryo. Although fate maps are very useful for identifying the precursors of an organ and for elucidating the developmental path by which the descendant cells populate that organ in the normal embryo, they do not illustrate the full developmental potential of a precursor cell or identify the mechanisms by which its fate is determined. To test for cell fate commitment, one compares a cell's normal repertoire of descendants in the intact embryo (the fate map) with those expressed after an experimental manipulation. Is the cell's fate fixed (committed) regardless of the surrounding cellular environment, or is it influenced by external factors provided by its neighbors? Using the comprehensive fate maps of the Xenopus embryo, we describe how to identify, isolate and culture single cleavage stage precursors, called blastomeres. This approach allows one to assess whether these early cells are committed to the fate they acquire in their normal environment in the intact embryo, require interactions with their neighboring cells, or can be influenced to express alternate fates if exposed to other types of signals.

The fate of an individual embryonic cell can be influenced by inherited molecules and/or by signals from neighboring cells. Utilizing fate maps of the cleavage stage Xenopus embryo, single blastomeres can be identified for culture in isolation to assess the contributions of inherited molecules versus cell-cell interactions.

Espianti blastomero al test per l&#39;Impegno cellulare Fate durante lo sviluppo embrionale

Fate maps, constructed from lineage tracing all of the cells of an embryo, reveal  which tissues descend from each cell of the embryo.  Although fate maps ...

Mechanical Stimulation-induced Calcium Wave Propagation in Cell Monolayers: The Example of Bovine Corneal Endothelial Cells

Intercellular communication is essential for the coordination of physiological processes between cells in a variety of organs and tissues, including the brain, liver, retina, cochlea and vasculature. In experimental settings, intercellular Ca2+-waves can be elicited by applying a mechanical stimulus to a single cell. This leads to the release of the intracellular signaling molecules IP3 and Ca2+ that initiate the propagation of the Ca2+-wave concentrically from the mechanically stimulated cell to the neighboring cells. The main molecular pathways that control intercellular Ca2+-wave propagation are provided by gap junction channels through the direct transfer of IP3 and by hemichannels through the release of ATP. Identification and characterization of the properties and regulation of different connexin and pannexin isoforms as gap junction channels and hemichannels are allowed by the quantification of the spread of the intercellular Ca2+-wave, siRNA, and the use of inhibitors of gap junction channels and hemichannels. Here, we describe a method to measure intercellular Ca2+-wave in monolayers of primary corneal endothelial cells loaded with Fluo4-AM in response to a controlled and localized mechanical stimulus provoked by an acute, short-lasting deformation of the cell as a result of touching the cell membrane with a micromanipulator-controlled glass micropipette with a tip diameter of less than 1 &mu;m. We also describe the isolation of primary bovine corneal endothelial cells and its use as model system to assess Cx43-hemichannel activity as the driven force for intercellular Ca2+-waves through the release of ATP. Finally, we discuss the use, advantages, limitations and alternatives of this method in the context of gap junction channel and hemichannel research.

Intercellular Ca2+-waves are driven by gap junction channels and hemichannels. Here, we describe a method to measure intercellular Ca2+-waves in cell monolayers in response to a local single-cell mechanical stimulus and its application to investigate the properties and regulation of gap junction channels and hemichannels.

La stimolazione meccanica indotta calcio Wave Propagation in monostrati cellulari: l&#39;esempio di bovini cellule endoteliali corneali

Intercellular communication is essential for the coordination of physiological processes between cells in a variety of organs and tissues, including the ...

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

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

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

Visualizzazione di sviluppo craniofacciale nei SOX10: Kaede transgenici Zebrafish line utilizzando Time-lapse Microscopia confocale

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

The Slice Culture Method for Following Development of Tooth Germs In Explant Culture

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental biologist. For many organs it is difficult to access developing tissue to allow monitoring during ex vivo culture. The slice culture method allows access to tissue so that morphogenetic movements can be followed and specific cell populations can be targeted for manipulation or lineage tracing.
In this paper we describe a method of slice culture that has been very successful for culture of tooth germs in a range of species. The method provides excellent access to the tooth germs, which develop at a similar rate to that observed in vivo, surrounded by the other jaw tissues. This allows tissue interactions between the tooth and surrounding tissue to be monitored. Although this paper concentrates on tooth germs, the same protocol can be applied to follow development of a number of other organs, such as salivary glands, Meckel&#39;s cartilage, nasal glands, tongue, and ear.

Here we detail a method to culture tooth germs in mandible slices using a tissue chopper. This method allows unique access to the tooth during development, providing excellent opportunity for manipulation and lineage tracing, not available using more traditional culture methods.

Il Metodo Culture Slice per seguire lo sviluppo dei germi dente Espianto Cultura

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental ...

Analyzing Craniofacial Morphogenesis in Zebrafish Using 4D Confocal Microscopy

Time-lapse imaging is a technique that allows for the direct observation of the process of morphogenesis, or the generation of shape. Due to their optical clarity and amenability to genetic manipulation, the zebrafish embryo has become a popular model organism with which to perform time-lapse analysis of morphogenesis in living embryos. Confocal imaging of a live zebrafish embryo requires that a tissue of interest is persistently labeled with a fluorescent marker, such as a transgene or injected dye. The process demands that the embryo is anesthetized and held in place in such a way that healthy development proceeds normally. Parameters for imaging must be set to account for three-dimensional growth and to balance the demands of resolving individual cells while getting quick snapshots of development. Our results demonstrate the ability to perform long-term in vivo imaging of fluorescence-labeled zebrafish embryos and to detect varied tissue behaviors in the cranial neural crest that cause craniofacial abnormalities. Developmental delays caused by anesthesia and mounting are minimal, and embryos are unharmed by the process. Time-lapse imaged embryos can be returned to liquid medium and subsequently imaged or fixed at later points in development. With an increasing abundance of transgenic zebrafish lines and well-characterized fate mapping and transplantation techniques, imaging any desired tissue is possible. As such, time-lapse in vivo imaging combines powerfully with zebrafish genetic methods, including analyses of mutant and microinjected embryos.

Time-lapse confocal imaging is a powerful technique useful for characterizing embryonic development. Here, we describe the methodology and characterize craniofacial morphogenesis in wild-type, as well as pdgfra, smad5, and smo mutant embryos.

Analizzando craniofacciale morfogenesi in Zebrafish Uso 4D Microscopia confocale

Time-lapse imaging is a technique that allows for the direct observation of the process of morphogenesis, or the generation of shape. Due to their optical ...

Alternative Cultures for Human Pluripotent Stem Cell Production, Maintenance, and Genetic Analysis

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and efficient expansion of large amounts of clinical-grade hPSCs are critical issues in hPSC-based therapies. Conventionally, hPSCs are propagated as colonies on both feeder and feeder-free culture systems. However, these methods have several major limitations, including low cell yields and generation of heterogeneously differentiated cells. To improve current hPSC culture methods, we have recently developed a new method, which is based on non-colony type monolayer (NCM) culture of dissociated single cells. Here, we present detailed NCM protocols based on the Rho-associated kinase (ROCK) inhibitor Y-27632. We also provide new information regarding NCM culture with different small molecules such as Y-39983 (ROCK I inhibitor), phenylbenzodioxane (ROCK II inhibitor), and thiazovivin (a novel ROCK inhibitor). We further extend our basic protocol to cultivate hPSCs on defined extracellular proteins such as the laminin isoform 521 (LN-521) without the use of ROCK inhibitors. Moreover, based on NCM, we have demonstrated efficient transfection or transduction of plasmid DNAs, lentiviral particles, and oligonucleotide-based microRNAs into hPSCs in order to genetically modify these cells for molecular analyses and drug discovery. The NCM-based methods overcome the major shortcomings of colony-type culture, and thus may be suitable for producing large amounts of homogeneous hPSCs for future clinical therapies, stem cell research, and drug discovery.

Here, we present human pluripotent stem cell (hPSC) culture protocols, based on non-colony type monolayer (NCM) growth of dissociated single cells. This new method, utilizing Rho-associated kinase inhibitors or the laminin isoform 521 (LN-521), is suitable for producing large amounts of homogeneous hPSCs, genetic manipulation, and drug discovery.

Le colture per pluripotenti umane alternative staminali produzione di celle, manutenzione e analisi genetica

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and ...

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

The generation of chimeric embryos is a widespread and powerful approach to study cell fates, tissue interactions, and species-specific contributions to the histological and morphological development of vertebrate embryos. In particular, the use of chimeric embryos has established the importance of neural crest in directing the species-specific morphology of the craniofacial complex. The method described herein utilizes two avian species, duck and quail, with remarkably different craniofacial morphology. This method greatly facilitates the investigation of molecular and cellular regulation of species-specific pattern in the craniofacial complex.&#160;Experiments in quail and duck chimeric embryos have already revealed neural crest-mediated tissue interactions and cell-autonomous behaviors that regulate species-specific pattern in the craniofacial skeleton, musculature, and integument. The great diversity of neural crest derivatives suggests significant potential for future applications of the quail-duck chimeric system to understanding vertebrate development, disease, and evolution.

This article describes a method to generate chimeric embryos that are&#160;designed to test the species-specific contributions of neural crest and/or other tissues to craniofacial development.

Valutare Contributi specie-specifiche per lo sviluppo craniofacciale Uso Chimere Quaglia-anatra

The generation of chimeric embryos is a widespread and powerful approach to study cell fates, tissue interactions, and species-specific contributions to ...