We thank Kwon laboratory members for helpful discussions. This work was supported by grants from NHLBI/NIH (R01HL111198) and Maryland Stem Cell Research Fund (MSCRF).

Todos los ratones fueron mantenidos a una Asociación Americana para la Acreditación de Cuidado de Animales de Laboratorio (AAALAC) acreditado por animalario de la Universidad Johns Hopkins y alojados de conformidad con los procedimientos establecidos en la Guía para el Cuidado y Uso de Animales de Laboratorio. El Cuidado y Uso de Animales Comité Institucional (IACUC) aprobó todos los protocolos experimentales. 1. Preparación Experimental <ol><li> Escudo placa de 12 pocillos con 10% de suero bovino fetal (FBS) en solución tamponada de fosfato (PBS) durante 60 min. </li><li> Retire solución de revestimiento y añadir 200 l de los medios de comunicación libre de suero (SFM). Girar la placa para asegurarse de que una película de los medios cubre toda la superficie. </li></ol> 2. Procedimientos Quirúrgicos <ol><li> La eutanasia a los ratones embarazadas que utilizan cuidado de los animales protocolo comité aprobados de la institución seguido por dislocación cervical para asegurar la eutanasia completa. </li><li> Rocíe y limpie la región del vientre del ratón con el 70%etanol. Mantener estrictas técnicas estériles para evitar la contaminación. </li><li> Use pinzas y tijeras para hacer un 0,5 cm2 incisión en la región del ombligo. </li><li> Utilice los dedos para pellizcar / agarrar la piel por encima y por debajo de la incisión y tire suavemente la piel en direcciones opuestas (cabeza y cola). </li><li> Utilice pinzas y tijeras para hacer una incisión inicial en la membrana en la región del ombligo. Cortar con cuidado la membrana en forma de V desde el ombligo hasta los ovarios en cada lado (2 x 1,5 cm 2), revelando así el útero. </li><li> El uso de fórceps para pellizcar el oviducto que conecta el útero con el ovario y tijeras para pellizcar el oviducto en el lado del ovario, liberando así el útero desde el ovario. </li><li> Tire suavemente hasta el útero por el oviducto con las pinzas y cortar el útero libre de la región de la vejiga con unas tijeras. </li><li> Tire del útero más arriba por el oviducto con las pinzas, y cortar el oviducto con unas tijeras en el otro lado, liberando de este modo el útero de la mOuse. </li><li> Transferir el útero a un tubo de 50 ml y añadir 20 ml de PBS frío estéril con Ca2 + y Mg2 +. PBS debe contener Ca 2+ y Mg 2+ durante la disección de embriones. </li><li> Agite suavemente el tubo durante 10 segundos para lavar el útero para la sangre. </li><li> Transferir el útero desde el tubo con pinzas y colocarlo en una placa de 10 ml y añadir 5 ml de PBS frío en la parte superior del útero. </li><li> Coloque el plato con el útero bajo un microscopio estereoscópico. Nota: Los pasos 02/13 a 02/19 requiere un microscopio estereoscópico. </li><li> Use dos pares de pinzas para abrir suavemente el útero y diseccionar sacos amnióticos con embriones desde el útero uno por uno. <ol><li> Use dos pares de pinzas para abrir cuidadosamente el saco amniótico que rodea al embrión, pellizcar el saco con uno fórceps y suavemente sacarlo de la embrión, utilizar las otras pinzas para cortar y liberar el saco amniótico a partir del embrión. Si un genotipo específico necesario, mantenga saco amniótico para el genotipado. </li></ol></li><li> Coloque el embrión en el lado y utilizar pinzas para cortar el 1 ° y 2 ° arco posterior al corazón entre el arco y la bolsa faríngea (Figura 1 A &#39;&#39;). </li><li> Voltear suavemente el embrión para el otro lado y utilizar pinzas para cortar la primera y segunda arco posterior al corazón entre el arco y la bolsa faríngea. </li><li> Utilice unas pinzas para cortar el tracto de salida cardíaco que todavía se está conectando el 1 y 2 de la faringe arcos al embrión. Retire los arcos, que todavía están unidos juntos en la forma de una mariposa (Figura 1B), a partir del embrión. </li><li> Utilice pinzas para pellizcar y suelte los arcos 1 st faríngeas del restante del tracto de salida cardíaco y endodermo del intestino anterior (Figura 1B &#39;&#39; se indica con línea discontinua y *). </li><li> El uso de fórceps para pellizcar y suelte los arcos faríngeos 2º del resto del tracto de salida cardíacoy endodermo del intestino anterior (Figura 1B &#39;&#39; se indica con línea discontinua y **). </li><li> Transferir cada par de arcos por separado utilizando fórceps y colocar ambas arcadas en el medio de un así designado. Plate 1 y 2 de la faringe arcos en pocillos separados. Asegúrese de que los arcos están en contacto con la película de los medios agregados en el paso 1.2. Es crucial que los arcos no están cubiertos por medio, ya que necesitan para hacer contacto con la superficie del pozo para la fijación durante este período. </li></ol> 3. Incubación e Imagen <ol><li> Incubar arcos plateados en la placa de 12 pocillos en 37 ° C / 5% de CO 2 durante 2 horas para arcos para fijar a la superficie también. </li><li> Añadir suavemente 200 l de 37 ° C SFM por el lado del pozo. Asegúrese de que los arcos permanecen unidos e incubar O / N. </li><li> Al día siguiente, comprobar visualmente que arcos faríngeos se unen y agregan suavidad 200 l de 37 ° C SFM por el lado de labien. Si arcos permanecen sin ataduras y flotante, retire con cuidado los medios de comunicación con una pipeta sin remover arcos hasta que sólo queda una película de los medios de comunicación. Utilice punta de la pipeta para colocar arcos en el medio de la etapa de bien y de repetición 3.1. </li><li> Monitorear diariamente; añadir ~ 100-200 l de los medios de comunicación cada segundo día para reemplazar cualquier medio evaporó. Nota: 24-48 h después de la migración de las células aparecen alrededor del arco y proliferar y migrar de arco en los próximos 5-8 días. Después de 36 a 72 horas de formación de los cardiomiocitos que baten se puede observar desde el 2º arco faríngeo (Figura 2B). Formación myotube se puede observar a partir de los 1 st faríngea arco 3-7 días después de la unión (Figura 2). </li></ol>

<ol>
	<li>Kelly, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+second+heart+field.">The second heart field.</a> Curr Top Dev Biol. 100, 33-65 (2012).</li><li>Bruneau, B. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+developmental+genetics+of+congenital+heart+disease.">The developmental genetics of congenital heart disease.</a> Nature. 451, 943-948 (2008).</li><li>Tzahor, E., Evans, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharyngeal+mesoderm+development+during+embryogenesis:+implications+for+both+heart+and+head+myogenesis.">Pharyngeal mesoderm development during embryogenesis: implications for both heart and head myogenesis.</a> Cardiovasc Res. 91, 196-202 (2011).</li><li>Uosaki, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+Contact+with+Endoderm-like+Cells+Efficiently+Induces+Cardiac+Progenitors+from+Mouse+and+Human+Pluripotent+Stem+Cells.">Direct Contact with Endoderm-like Cells Efficiently Induces Cardiac Progenitors from Mouse and Human Pluripotent Stem Cells.</a> PLoS One. 7 (10), e46413 (2012).</li><li>Cheng, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fibronectin+mediates+mesendodermal+cell+fate+decisions.">Fibronectin mediates mesendodermal cell fate decisions.</a> Development. 140, 2587-2596 (2013).</li><li>Kwon, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+regulatory+pathway+involving+Notch1/beta-catenin/Isl1+determines+cardiac+progenitor+cell+fate.">A regulatory pathway involving Notch1/beta-catenin/Isl1 determines cardiac progenitor cell fate.</a> Nature cell biology. 11, 951-957 (2009).</li><li>Shenje, L. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precardiac+deletion+of+Numb+and+Numblike+reveals+renewal+of+cardiac+progenitors.">Precardiac deletion of Numb and Numblike reveals renewal of cardiac progenitors.</a> Elife. 3, e02164 (2014).</li><li>Grevellec, A., Tucker, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pharyngeal+pouches+and+clefts:+Development,+evolution,+structure+and+derivatives.">The pharyngeal pouches and clefts: Development, evolution, structure and derivatives.</a> Semin Cell Dev Biol. 21, 325-332 (2010).</li><li>Kwon, C., Cordes, K. R., Srivastava, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt/beta-catenin+signaling+acts+at+multiple+developmental+stages+to+promote+mammalian+cardiogenesis.">Wnt/beta-catenin signaling acts at multiple developmental stages to promote mammalian cardiogenesis.</a> Cell Cycle. 7, 3815-3818 (2008).</li><li>Cho, G. S., Fernandez, L., Kwon, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regenerative+medicine+for+the+heart:+perspectives+on+stem-cell+therapy.">Regenerative medicine for the heart: perspectives on stem-cell therapy.</a> Antioxid Redox Signal. 21, 2018-2031 (2014).</li></ol>

The authors have nothing to disclose.

En este vídeo, se demuestra cómo aislar y cultura primero y segundo arcos faríngeos de 9,5 días de edad embriones de ratón. Arcos faríngeos se transitoria, segmentados abultamientos que aparecen en el lado craneolateral de embriones en desarrollo 9, que contienen bloques cardiaca de creación de células progenitoras múltiples potentes para hacer que el corazón durante la embriogénesis 10,11 -en segundo arcos y progenitores musculares cabeza en primera arcos 8 . <p class="jo...

Las células del mesodermo faríngeos dan lugar a partes del corazón y los músculos faríngeos. Durante el desarrollo embrionario, las células progenitoras multipotentes cardiacos desde el segundo campo corazón migran desde el mesodermo faríngea y pueblan el tracto de salida del ventrículo derecho y cardiaco, y su desarrollo anormal está estrechamente asociada con la enfermedad-el corazón congénita causa de defectos de nacimiento y-defecto de nacimiento muertes relacionadas en seres humanos 1-3. Estudios recientes han demostrado que mesodermo faríngea contribuye a la cabeza músculos, además del corazón, haciendo que el mesodermo una parte crítica del desarrollo cardio-4 craneofacial. Por lo tanto, los procesos de desarrollo incluyendo la inducción, proliferación, y diferenciación de progenitores de la cabeza y del corazón en el mesodermo faríngea están bajo investigación activa 5-7. Hasta hace poco, seguía siendo desconocida si las células progenitoras cardíacas experimentan witho expansióndiferenciación ut, debido en parte a la falta de información sobre su entorno celular. Nuestro estudio reciente sugiere que los arcos faríngeos sirven como un microambiente para la renovación de los progenitores cardíacos y musculares y pueden ser cultivadas ex vivo durante varias semanas 8. Este método de explante ofrece una novedosa y única oportunidad de estudiar el desarrollo de progenitores cardio-craneofacial ex vivo.

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			<td>PBS + Ca2 + Mg2</td>
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			<td>10cm petri plates</td>
			<td>Fishersci</td>
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			<td>15-016-CV</td>
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			<td>Ham&#8217;s F12</td>
			<td>Cellgro</td>
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			<td>Gibco</td>
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			<td>B27-retinoic acid</td>
			<td>Gibco</td>
			<td>12587-010</td>
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			<td>10% BSA (in PBS) &#224; (Invitrogen Cat#. P2489)</td>
			<td>Life Sciences</td>
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			<td>100X Glutamine (Gibco Cat.# 25030-081)</td>
			<td>Gibco</td>
			<td>35050-61</td>
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			<td>100X Pen/Strep (Gibco Cat#. 15070-063)</td>
			<td>Gibco</td>
			<td>15140-122</td>
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ex vivo culture of pharyngeal arches to study heart and muscle progenitors and their niche

El mesodermo faríngea de los embriones en desarrollo contribuye a amplias regiones de la cabeza y la musculatura del corazón. Hemos desarrollado un nuevo método para estudiar la cabeza y progenitor corazón desarrollo de las células con arcos faríngeos (también conocido como arcos branquiales) ex vivo. Usando este método, hemos descrito recientemente que el segundo arco faríngeo contiene progenitores corazón auto-renovación y sirve como un microambiente para la expansión de los progenitores durante el desarrollo del corazón de ratón. Las células progenitoras permanecen indiferenciadas y expansivo en el interior del arco, pero rápidamente se convierten en cardiomiocitos funcionales a medida que migran fuera del arco. También informó que el primer arco faríngeo contiene progenitores musculares que dan lugar a miotubos después de dejar el arco. Aquí, se demuestra el procedimiento para la disección y la cultura ex vivo de primer y segundo arcos faríngeos de desarrollo de embriones de ratón. El método permite a uno para estudiar la cabeza y el corazón progenitor / dev muscularelopment, incluyendo cardiomiocitos y myotube formación en detalle ex vivo.

Durante el desarrollo, los progenitores del músculo y del corazón faciales se pueden remontar a medida que proliferan y migran desde el 1 ° y 2 ° arco faríngeo, para convertirse en la cabeza y la musculatura del corazón, respectivamente (Figura 1 A, A &#39;y A&#39; &#39;). El cultivo de arcos faríngeos ofrece una forma única para estudiar el corazón y el músculo de desarrollo en detalle ex vivo. Después de la disección y la unión de los arcos faríngeos,...

Watch this Scientific Journal Video about Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche at JoVE.com

Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

Here, we present a protocol to culture pharyngeal arches to study the biology of heart and muscle progenitor cells and their microenvironment.

Ex Vivo Cultura de faríngea Arcos para el Estudio de corazón y músculo Progenitores y su nicho

The pharyngeal mesoderm of developing embryos contributes to broad regions of head and heart musculature. We have developed a novel method to study head ...

ex-vivo-culture-pharyngeal-arches-to-study-heart-muscle-progenitors

Research

JoVE Journal

Developmental Biology

Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

7.7K vistas.  Johns Hopkins University School of Medicine. Here, we present a protocol to culture pharyngeal arches to study the biology of heart and muscle progenitor cells and their microenvironment.

Video: Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

Using Ex Vivo Upright Droplet Cultures of Whole Fetal Organs to Study Developmental Processes during Mouse Organogenesis

Investigating organogenesis in utero is a technically challenging process in placental mammals due to inaccessibility of reagents to embryos that develop within the uterus. A newly developed ex vivo upright droplet culture method provides an attractive alternative to studies performed in utero. The ex vivo droplet culture provides the ability to examine and manipulate cellular interactions and diverse signaling pathways through use of various blocking and activating compounds; additionally, the effects of various pharmacological reagents on the development of specific organs can be studied without unwanted side effects of systemic drug delivery in utero. As compared to other in vitro systems, the droplet culture not only allows for the ability to study three-dimensional morphogenesis and cell-cell interactions, which cannot be reproduced in mammalian cell lines, but also requires significantly less reagents than other ex vivo and in vitro protocols. This paper demonstrates proper mouse fetal organ dissection and upright droplet culture techniques, followed by whole organ immunofluorescence to demonstrate the effectiveness of the method. The ex vivo droplet culture method allows the formation of organ architecture comparable to what is observed in vivo and can be utilized to study otherwise difficult-to-study processes due to embryonic lethality in in vivo models. As a model application system, a small-molecule inhibitor will be utilized to probe the role of vascularization in testicular morphogenesis. This ex vivo droplet culture method is expandable to other fetal organ systems, such as lung and potentially others, although each organ must be extensively studied to determine any organ-specific modifications to the protocol. This organ culture system provides flexibility in experimentation with fetal organs, and results obtained using this technique will help researchers gain insights into fetal development.

Using Ex Vivo Upright Droplet Cultures of Whole Fetal Organs to Study Developmental Processes during Mouse Organogenesis

The&#160;ex vivo&#160;upright droplet culture is an alternative to current&#160;in vitro&#160;and&#160;in vivo&#160;experimental techniques. This protocol is easy to perform and requires smaller amounts of reagent, while permitting the ability to manipulate and study fetal vascularization, morphogenesis, and organogenesis.

Usando<em&gt; Ex Vivo</em&gt; Culturas Upright Gotita de enteros fetales Órganos para estudiar los procesos de desarrollo durante Ratón Organogénesis

Investigating organogenesis in utero is a technically challenging process in placental mammals due to inaccessibility of reagents to embryos that develop ...

Investigación

Biología del Desarrollo

Ex Vivo Culture of Chick Cerebellar Slices and Spatially Targeted Electroporation of Granule Cell Precursors

The cerebellar external granule layer (EGL) is the site of the largest transit amplification in the developing brain, and an excellent model for studying neuronal proliferation and differentiation. In addition, evolutionary modifications of its proliferative capability have been responsible for the dramatic expansion of cerebellar size in the amniotes, making the cerebellum an excellent model for evo-devo studies of the vertebrate brain. The constituent cells of the EGL, cerebellar granule progenitors, also represent a significant cell of origin for medulloblastoma, the most prevalent paediatric neuronal tumour. Following transit amplification, granule precursors migrate radially into the internal granular layer of the cerebellum where they represent the largest neuronal population in the mature mammalian brain. In chick, the peak of EGL proliferation occurs towards the end of the second week of gestation. In order to target genetic modification to this layer at the peak of proliferation, we have developed a method for genetic manipulation through ex vivo electroporation of cerebellum slices from embryonic Day 14 chick embryos. This method recapitulates several important aspects of in vivo granule neuron development and will be useful in generating a thorough understanding of cerebellar granule cell proliferation and differentiation, and thus of cerebellum development, evolution and disease.

Ex Vivo Culture of Chick Cerebellar Slices and Spatially Targeted Electroporation of Granule Cell Precursors

The cerebellar external granule layer is the site of the largest transit amplification in the developing brain. Here, we present a protocol to target genetic modification to this layer at the peak of proliferation using ex vivo electroporation and culture of cerebellar slices from embryonic Day 14 chick embryos.

Ex Vivo Cultura de polluelo cerebelosos Rebanadas y espacialmente focalizadas Electroporación de gránulos precursores celulares

The cerebellar external granule layer (EGL) is the site of the largest transit amplification in the developing brain, and an excellent model for studying ...

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing cardiovascular progenitors during development and disease. While a number of factors have been implicated in epicardium-derived cell (EPDC) mobilization, the mechanisms governing their subsequent migration and differentiation are poorly understood. Here, we present in vitro and ex vivo strategies to study EPDC motility and differentiation. First, we describe a method of obtaining primary epicardial cells by outgrowth culture from the embryonic mouse heart. We also introduce a detailed protocol to assess three-dimensional migration of labeled EPDC in an organ culture system. We provide evidence using these techniques that genetic deletion of myocardin-related transcription factors in the epicardium attenuates EPDC migration. This approach serves as a platform to evaluate candidate modifiers of EPDC biology and could be used to develop genetic or chemical screens to identify novel regulators of EPDC mobilization that might be useful for cardiac repair.

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

Here, we describe methods for isolating primary mouse epicardial cells by an outgrowth culture assay and assessing the functional migration of epicardial-derived cells (EPDC) using an ex vivo heart culture system. These protocols are suitable for identifying genetic and chemical modulators of epicardial epithelial-to-mesenchymal transition (EMT) and motility.

Consecuencia del epicardio y Ensayo de Cultivo<em&gt; Ex Vivo</em&gt; Evaluación de la migración de células derivadas del epicardio

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing ...

Identification Of Erythromyeloid Progenitors And Their Progeny In The Mouse Embryo By Flow Cytometry

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where they act as front line sentinels of infection and tissue damage. While other immune cells are continuously renewed from hematopoietic stem and progenitor cells (HSPC) located in the bone marrow, a lineage of macrophages, known as resident macrophages, have been shown to be self-maintained in tissues without input from bone marrow HSPCs. This lineage is exemplified by microglia in the brain, Kupffer cells in the liver and Langerhans cells in the epidermis among others. The intestinal and colon lamina propria are the only adult tissues devoid of HSPC-independent resident macrophages. Recent investigations have identified that resident macrophages originate from the extra-embryonic yolk sac hematopoiesis from progenitor(s) distinct from fetal hematopoietic stem cells (HSC). Among yolk sac definitive hematopoiesis, erythromyeloid progenitors (EMP) give rise both to erythroid and myeloid cells, in particular resident macrophages. EMP are only generated within the yolk sac between E8.5 and E10.5 days of development and they migrate to the fetal liver as early as circulation is connected, where they expand and differentiate until at least E16.5. Their progeny includes erythrocytes, macrophages, neutrophils and mast cells but only EMP-derived macrophages persist until adulthood in tissues. The transient nature of EMP emergence and the temporal overlap with HSC generation renders the analysis of these progenitors difficult. We have established a tamoxifen-inducible fate mapping protocol based on expression of the macrophage cytokine receptor Csf1r promoter to characterize EMP and EMP-derived cells in vivo by flow cytometry.

While infiltrating macrophages are continuously recruited to adult tissues from circulating precursors, resident macrophages seed their tissue during development, where they are maintained without further input from progenitors. The progenitors for resident macrophages were recently identified. Here, we present methods for the genetic fate mapping of the resident macrophage progenitors.

Identificación de progenitores eritromioideos y su progenie en el embrión de ratón por citometría de flujo

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where ...

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced in vivo throughout the rapid developmental period. Multiple processes can be studied including cell proliferation, gene expression, cell migration and morphogenesis. Importantly, the generation of chimeras through transplantations can be easily performed, allowing mosaic labeling and tracking of individual cells under the influence of the host environment. For example, by combining functional gene manipulations of the host embryo (e.g., through morpholino microinjection) and live imaging, the effects of extrinsic, cell nonautonomous signals (provided by the genetically modified environment) on individual transplanted donor cells can be assessed. Here we demonstrate how this approach is used to compare the onset of fluorescent transgene expression as a proxy for the timing of cell fate determination in different genetic host environments.
In this article, we provide the protocol for microinjecting zebrafish embryos to mark donor cells and to cause gene knockdown in host embryos, a description of the transplantation technique used to generate chimeric embryos, and the protocol for preparing and running in vivo time-lapse confocal imaging of multiple embryos. In particular, performing multiposition imaging is crucial when comparing timing of events such as the onset of gene expression. This requires data collection from multiple control and experimental embryos processed simultaneously. Such an approach can easily be extended for studies of extrinsic influences in any organ or tissue of choice accessible to live imaging, provided that transplantations can be targeted easily according to established embryonic fate maps.

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

Live tracking of individual WT retinal progenitors in distinct genetic backgrounds allows for the assessment of the contribution of cell non-autonomous signaling during neurogenesis. Here, a combination of gene knockdown, chimera generation via embryo transplantation and in vivo time-lapse confocal imaging was utilized for this purpose.

En vivo de imágenes de transgénicos de la Expresión Génica en el Estimado de retina progenitores en embriones de pez cebra quiméricos para estudiar celulares Influencias no autónomos

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced ...

Isolation, Culture, and Differentiation of Bone Marrow Stromal Cells and Osteoclast Progenitors from Mice

Bone marrow stromal cells (BMSCs) constitute a cell population routinely used as a representation of mesenchymal stem cells in vitro. They reside within the bone marrow cavity alongside hematopoietic stem cells (HSCs), which can give rise to red blood cells, immune progenitors, and osteoclasts. Thus, extractions of cell populations from the bone marrow results in a very heterogeneous mix of various cell populations, which can present challenges in experimental design and confound data interpretation. Several isolation and culture techniques have been developed in laboratories in order to obtain more or less homogeneous populations of BMSCs and HSCs invitro. Here, we present two methods for isolation of BMSCs and HSCs from mouse long bones: one method that yields a mixed population of BMSCs and HSCs and one method that attempts to separate the two cell populations based on adherence. Both methods provide cells suitable for osteogenic and adipogenic differentiation experiments as well as functional assays.

In this article, we present methods to isolate and differentiate bone marrow stromal cells and hematopoietic stem cells from mouse long bones. Two different protocols are presented yielding different cell populations suitable for expansion and differentiation into osteoblasts, adipocytes, and osteoclasts.

Aislamiento, cultivo y diferenciación de células estromales de médula ósea y progenitores de los osteoclastos de los ratones

Bone marrow stromal cells (BMSCs) constitute a cell population routinely used as a representation of mesenchymal stem cells in vitro. They reside within ...

Application of Chronic Stimulation to Study Contractile Activity-induced Rat Skeletal Muscle Phenotypic Adaptations

Skeletal muscle is a highly adaptable tissue, as its biochemical and physiological properties are greatly altered in response to chronic exercise. To investigate the underlying mechanisms that bring about various muscle adaptations, a number of exercise protocols such as treadmill, wheel running, and swimming exercise have been used in the animal studies. However, these exercise models require a long period of time to achieve muscle adaptations, which may be also regulated by humoral or neurological factors, thus limiting their applications in studying the muscle-specific contraction-induced adaptations. Indirect low frequency stimulation (10 Hz) to induce chronic contractile activity (CCA) has been used as an alternative model for exercise training, as it can successfully lead to muscle mitochondrial adaptations within 7 days, independent of systemic factors. This paper details the surgical techniques required to apply the treatment of CCA to the skeletal muscle of rats, for widespread application in future studies.

This protocol describes the use of the chronic contractile activity model of exercise to observe stimulation-induced skeletal muscle adaptations in the rat hindlimb.

Aplicación de la estimulación crónica para estudiar adaptaciones fenotípicas de músculo esquelético de rata inducida por actividad contráctil

Skeletal muscle is a highly adaptable tissue, as its biochemical and physiological properties are greatly altered in response to chronic exercise. To ...

In Vivo Imaging of Muscle-tendon Morphogenesis in Drosophila Pupae

Muscles together with tendons and the skeleton enable animals including humans to move their body parts. Muscle morphogenesis is highly conserved from animals to humans. Therefore, the powerful Drosophila model system can be used to study concepts of muscle-tendon development that can also be applied to human muscle biology. Here, we describe in detail how morphogenesis of the adult muscle-tendon system can be easily imaged in living, developing Drosophila pupae. Hence, the method allows investigating proteins, cells and tissues in their physiological environment. In addition to a step-by-step protocol with helpful tips, we provide a comprehensive overview of fluorescently tagged marker proteins that are suitable for studying the muscle-tendon system. To highlight the versatile applications of the protocol, we show example movies ranging from visualization of long-term morphogenetic events &#8211; occurring on the time scale of hours and days &#8211; to visualization of short-term dynamic processes like muscle twitching occurring on time scale of seconds. Taken together, this protocol should enable the reader to design and perform live-imaging experiments for investigating muscle-tendon morphogenesis in the intact organism.

In Vivo Imaging of Muscle-tendon Morphogenesis in Drosophila Pupae

Here, we present an easy-to-use and versatile method to perform live imaging of developmental processes in general and muscle-tendon morphogenesis in particular in living Drosophila pupae.

En Vivo Proyección de imagen del músculo-tendón morfogénesis en Drosophila pupa

Muscles together with tendons and the skeleton enable animals including humans to move their body parts. Muscle morphogenesis is highly conserved from ...

Generation of First Heart Field-like Cardiac Progenitors and Ventricular-like Cardiomyocytes from Human Pluripotent Stem Cells

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is a pre-requisite for cell-based cardiac therapies and disease modeling. We have recently shown that Id genes are both necessary and sufficient to specify first heart field progenitors during vertebrate development. This differentiation protocol leverages these findings and uses Id1 overexpression in combination with Activin A as potent specifying cues to produce first heart field-like (FHF-L) progenitors. Importantly, resulting progenitors efficiently differentiate (~70&#8211;90%) into ventricular-like cardiomyocytes. Here we describe a detailed method to 1) generate Id1-overexpressing hPSCs and 2) differentiate scalable quantities of cryopreservable FHF-L progenitors and ventricular-like cardiomyocytes.

Here we describe a scalable method, using a simple combination of Activin A and lentivirus-mediated Id1-overexpression, to generate first heart field-like cardiac progenitors and ventricular-like cardiomyocytes from human pluripotent stem cells.

Generación del primer corazón campo-como progenitores cardiaca y Ventricular como cardiomiocitos desde células madre humanas pluripotentes

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is ...

Ex Vivo Perfusion of the Rodent Placenta

The placenta is a key organ during pregnancy that serves as a barrier to fetal xenobiotic exposure and mediates the exchange of nutrients for waste. An assay is described here to perfuse an isolated rat placenta and evaluate the maternal-to-fetal translocation of xenobiotics ex vivo. In addition, the evaluation of physiological processes such as fluid flow to the fetus and placental metabolism may be conducted with this methodology. This technique is suitable for evaluating maternal-to-fetal kinetics of pharmaceutical candidates or environmental contaminants. In contrast to current alternative approaches, this methodology allows the evaluation of the isolated maternal-fetal vasculature, with the systemic neural or immune involvement removed, allowing any observed changes in physiological function to be attributable to local factors within the isolated tissue.

Here is presented a protocol of ex vivo maternal-fetal vascular perfusion to enable the administration of a test article into maternal vasculature and to evaluate placental transfer of xenobiotic particles or pharmacological agents in addition to alterations in placental physiology.

Ex vivo perfusion de la placenta de roedores

The placenta is a key organ during pregnancy that serves as a barrier to fetal xenobiotic exposure and mediates the exchange of nutrients for waste. An ...