Este trabajo fue financiado por R01-R01 DE018234 y DE019638.

1. Preparación del tejido de un donante <ol><li> Preparar medios de cultivo, afilar pernos de vidrio, afilar agujas de tungsteno. </li><li> Recoger embrión a partir de cáscara, lavado en PBS helado. <ol class="lalpha"><li> Con una jeringa de 10 ml y una aguja de calibre 18 extraer 1,0 ml de albúmina en la punta de la cáscara del huevo. </li><li> Haz un pequeño agujero en la parte superior de la misma utilizando el punto de tijeras, y luego se corta una abertura circular para exponer el embrión </li></ol></li><li> Quitar la cabeza y el lugar en DMEM (libre de suero, la temperatura ambiente) </li><li> Diseccionar proceso frontonasal del embrión (o en el sitio de otros donantes como el proceso maxilar o mandibular) </li><li> Compendio de 2.4U / mL dispasa en PBS en hielo durante 20 minutos </li><li> Cubrir los tejidos con DMEM con BSA al 1% para detener la digestión </li><li> El uso de agujas afiladas de tungsteno para ectodermo separado, mesénquima, y ​​neuroectodermo </li><li> Tienda de injerto de tejido en DMEM BSA al 1% en el hielo hasta el ordenador está listo para el trasplante </li></ol> 2. La preparación de la acogida <ol><li> Exponer el embrión <ol class="lalpha"><li> Con una jeringa de 10 ml y una aguja de calibre 18 extraer 1,0 ml de albúmina en la punta de la cáscara del huevo. </li><li> Haz un pequeño agujero en la parte superior de la misma utilizando el punto de tijeras. Coloque un pedazo de cinta adhesiva sobre el agujero, y luego se corta una abertura circular para exponer el embrión. </li></ol></li><li> Utilizando dos pares de pinzas, sujete el amnios y el desgarro con cuidado para hacer un agujero. </li><li> Gire la cabeza colocando un par de pinzas en el ojo derecho y la aplicación de presión. Mientras mantiene la cabeza firme, utilice una aguja de tungsteno para eliminar el ectodermo de acogida para dar cabida a la corrupción. </li><li> Transferencia del injerto al huésped con una pipeta de vidrio. </li><li> La posición del injerto para reemplazar el ectodermo eliminado. Inserte un vaso en cada esquina del tejido injertado para fijar el injerto en su lugar. Para hacer alfileres de cristal, tirar de un tubo capilar a una punta fina sobre una llama de alcohol. </li><li> Coloque cinta firmemente sobre el agujero y volver embrión de la incubadora de tiempo adecuado para el análisis. </li><li> véase también: 9 </li></ol> 3. Los resultados representativos: Para evaluar las quimeras, los embriones deben ser recogidos y procesados ​​para el análisis de la distribución de los anfitriones y los tejidos del donante. Para la detección de células de codorniz, inmunohistoquímica utilizando el anticuerpo QcPN (que se describe en: 3) se emplea, y para la detección de células de ratón, hibridación in situ en secciones de parafina se utilizan 6. Las células del donante se debe restringir al epitelio, y no debe haber evidencia de donantes tejidos mesenquimales (Figura 1). La presencia de células del donante aislado en el mesénquima indica la presencia de células de la contaminación de la cresta neural que confundir cualquier interpretación morfológica debido a la influencia de estas células en muchos aspectos del desarrollo facial (por ejemplo, 10). Una vez convencidos de que la técnica de injerto libre de contaminantes mesénquima, las medidas de resultado más morfológicos o moleculares se pueden utilizar para evaluar las quimeras. Para nuestros propósitos, hemos detectado la presencia de los cartílagos y los huesos ectópico que se correspondía con la duplicación de la mandíbula superior que fueron inducidos por los tejidos trasplantados (Figura 2), y los cambios moleculares en los tejidos mesenquimales en respuesta a la ectodermo injerto (Figura 3) 5,6. <img src="/files/ftp_upload/2557/2557fig1.jpg" alt="Figura 1" /> Figura 1. Evaluación de quimerismo (A) Anti-manchas QcPN se utiliza para detectar células de codorniz en la codorniz, pollo quimeras. No hay evidencia de manchas en el mesénquima. (B) La hibridación in situ se utiliza para detectar la expresión de las transcripciones B2 SINE en quimeras pollo ratón. Expresión está restringida al ectodermo que incluye el injerto. <img src="/files/ftp_upload/2557/2557fig2.jpg" alt="Figura 2" /> Tinción de la figura 2. Tricrómica muestra la duplicación del esqueleto de la mandíbula superior en (A) de codorniz-chick quimera, y (B) quimeras pollo ratón. <img src="/files/ftp_upload/2557/2557fig3.jpg" alt="Figura 3" /> Figura 3. El ectodermo regultes la expresión de genes en el mesénquima. (A) Normal BMP7 expresión en el mesénquima de un embrión de pollo (radiactivos hibridación in situ con señal positiva pseudo-color rojo en Adobe Photoshop). (B) la expresión BMP7 se induce en el mesénquima adyacente al injerto (flecha) en embriones quiméricos.

<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>

El uso de este método de trasplante nos ha permitido determinar que el ectodermo contiene información de señalización que regula la polaridad dorsoventral y extensión proximodistal de la mandíbula superior. La similitud de resultados cuando se utiliza la codorniz o ectodermo del ratón, y la conservación de las señales moleculares en este tejido, entre muchas especies de 6,11 indica que este es un centro altamente conservadas de señalización entre los vertebrados. Por otra parte, otros investigadore...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>1x PBS</td>
<td>&nbsp;</td>
<td>TEK</td>
<td>TEKZR114</td>
<td>&nbsp;</td>
<tr>
<td>DMEM</td>
<td>&nbsp;</td>
<td>UCSF</td>
<td>CCFDA003</td>
<td>&nbsp;</td>
<tr>
<td>BSA</td>
<td>&nbsp;</td>
<td>SIGMA</td>
<td>A7906</td>
<td>&nbsp;</td>
<tr>
<td>Dispase</td>
<td>&nbsp;</td>
<td>GIBCO</td>
<td>17105-041</td>
<td>&nbsp;</td>
<tr>
<td>35x10 mm Petri dish</td>
<td>&nbsp;</td>
<td>Falcon</td>
<td>1008</td>
<td>&nbsp;</td>
<tr>
<td>No. 5 Dumont forceps</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11252-20</td>
<td>&nbsp;</td>
<tr>
<td>Scissors</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>14058-11</td>
<td>&nbsp;</td>
<tr>
<td>Spring Scissors</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>15010-11</td>
<td>&nbsp;</td>
<tr>
<td>Needle holder</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>26016-12</td>
<td>&nbsp;</td>
<tr>
<td>Tungsten Needle</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>26000</td>
<td>&nbsp;</td>
<tr>
<td>Microcapillary tube </td>
<td>&nbsp;</td>
<td>Drummond Scientific Company</td>
<td>3-000-225-G</td>
<td>&nbsp;</td>
<tr>
<td>Pasteur Pipets</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>13-678-6B</td>
<td>&nbsp;</td>
<tr>
<td>Spring scissors</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>15010-11 </td>
<td>&nbsp;</td>
<tr>
<td>Blade holder</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>10052-11 </td>
<td>&nbsp;</td>
<tr>
<td>Razor blade</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>10050-00</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

assessing signaling properties of ectodermal epithelia during craniofacial development

La accesibilidad de los embriones de aves ha ayudado a los embriólogos experimentales entender el destino de las células durante el desarrollo y el papel de las interacciones de los tejidos que regulan los patrones y la morfogénesis de los vertebrados (por ejemplo, 1, 2, 3, 4). Aquí, se expone un método que explota esta accesibilidad a la prueba de la señalización y las propiedades de los patrones de tejidos del ectodermo durante el desarrollo facial. En estos experimentos, se crea la codorniz-chick chick 5 o 6 quimeras de ratón mediante el trasplante de la superficie ectodermo cefálico que cubre la mandíbula superior de la codorniz o el ratón sobre cualquiera de la misma región o de una región ectópica de embriones de pollo. El uso de la codorniz como tejido de un donante para el trasplante en los pollos se ha desarrollado para tomar ventaja de un marcador nucleolar presente en la codorniz, pero no las células de pollo, lo que permite a los investigadores distinguir anfitrión y tejidos de donantes 7. Del mismo modo, un elemento repetitivo está presente en el genoma del ratón y se expresa doquier, lo que nos permite distinguir anfitrión y tejidos de donantes en el ratón-chick quimeras 8. El uso de ectodermo ratón como donantes de tejidos en gran medida ampliar nuestra comprensión de estas interacciones de tejidos, ya que esto nos permitirá poner a prueba las propiedades de señalización del ectodermo derivan de varios embriones mutantes.

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

En este artículo se describe una técnica de trasplante de tejido que se diseñó para probar la señalización y las propiedades de los patrones de la superficie del ectodermo cefálico durante el desarrollo craneofacial.

La evaluación de las propiedades de señalización de ectodérmica epitelio durante el desarrollo craneofacial

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 vistas.  University of California San Francisco. En este artículo se describe una técnica de trasplante de tejido que se diseñó para probar la señalización y las propiedades de los patrones de la superficie del ectodermo cefálico durante el desarrollo craneofacial.

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.

Electroporación de mesénquima craneofacial

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

Investigación

Biología

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.

El análisis genético rápido de epitelio-mesenquimal de señalización durante la regeneración del cabello

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.

Celular seguimiento mediante fotoconvertible proteínas durante el desarrollo de pez cebra

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.

Los explantes blastómeras para la Prueba de Compromiso destino celular durante el desarrollo embrionario

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.

Mecánica estimulación inducida por calcio Propagación de Ondas en monocapas de células: el ejemplo de las especies bovina células endoteliales corneales

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.

Visualización de Desarrollo Craneofacial en los SOX10: Kaede pez cebra transgénico Línea Usando Time-lapse microscopía confocal

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.

El método de cultivo de la rebanada por Siguiendo desarrollo de gérmenes de dientes en Explante 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.

Analizando Craneofacial en la morfogénesis de pez cebra Utilizando 4D Microscopía Confocal

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.

Culturas alternativas para Pluripotentes Stem Cell Production, mantenimiento y análisis genético

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.

Evaluar Aportes específicos de la especie para el desarrollo craneofacial Utilizando quimeras Quail-pato

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