Este trabajo es apoyado por un fondo de arranque desde el Departamento de Ciencias Biológicas de la Universidad de Purdue.

Parte 1: Preparativos antes de microdisección <ol><li> Soluciones <ol class="lalpha"><li> E3 medio 4 (5 mM NaCl, 0,17 mM KCl, 0,33 mM CaCl 2 y 0,33 mM MgSO 4). </li><li> Solución de Ringer 1, 5 (116 mM NaCl, 2,9 mM KCl, 1,8 mM CaCl 2, 5 mM HEPES, pH 7.2), esterilizado por filtración. </li><li> NaOH 5N. </li></ol></li><li> Ataque químico de las agujas de tungsteno <ol class="lalpha"><li> Asegurar un pequeño vaso que contiene NaOH 5 N en una placa de Petri de arcilla. </li><li> Adjuntar un clip de papel en el lado del vaso, por lo que entra en contacto con la solución de NaOH. </li><li> Conecte el electrodo negativo de una fuente de alimentación de CC en el clip y el electrodo positivo a un extremo de una pieza corta (~ 2 cm) de alambre de tungsteno. </li><li> Envuelva el otro extremo del alambre de tungsteno con una bola de arcilla y sumergir este extremo en la solución de NaOH. </li><li> Aumentar la tensión a unos 3V y sumergir el hilo hacia arriba y abajo en la solución de NaOH hasta una velocidad de grabado bien se alcanza. Una aguja en buena calidad por lo general puede ser grabada en 10 minutos. </li><li> El alambre de tungsteno expuesta a la disolución se volverá gradualmente más delgada. Cuando la bola de arcilla cae, el otro lado del alambre que está todavía en el electrodo positivo tendrá una forma aguja. </li><li> Enjuague la aguja con solución de Ringer o E3 para eliminar los depósitos de sal. </li><li> Ponga la aguja en un aplicador de madera con una cinta o un soporte de aguja para un fácil manejo. </li></ol></li><li> Placas de cultivo <ol class="lalpha"><li> El Falcon 60 x 15 mm y placas de cultivo de poliestireno están listos para usar para la microdisección de retina. </li><li> Para la disección de RPE-adjunto retina, aplastar a dos embriones por completo en una placa de cultivo con solución de Ringer para deshacerse de la adherencia de la superficie de 30 minutos antes de la disección. Poco antes de la disección, se lava la placa extensamente con solución de Ringer fresca. </li></ol></li><li> Los embriones de recogida y puesta en escena <ol class="lalpha"><li> Adultos de pez cebra se mantienen tal como se describe 4, 5. </li><li> Separar los peces de los padres en los tanques de cría estática pares por un divisor de la noche antes de la reproducción. </li><li> Quitar el divisor después de la luz de la habitación se enciende en la mañana siguiente. Permiten que los padres se cruzan en intervalos de 10 minutos cada media hora. Separar el pescado después de cada cruce. </li><li> Mantener los embriones obtenidos de cada cruce en el medio de E3 por separado a 28 ° C. </li><li> Embriones etapa de 10 a 12 horas después de la fecundación (HPF) y re-escenificar inmediatamente antes de la disección en los puntos de tiempo específicos, de acuerdo con los criterios establecidos 1, 6. </li></ol></li></ol> Parte 2: Disección - la extracción del cerebro y una exposición de los ojos <ul><li> Los procedimientos descritos en esta sección son comunes para la disección de la retina (la parte 3A) y RPE-adjunto retina (parte 3 B). </li><li> Todas las disecciones bien se realiza por un extremo de la pinza Dumont y con la asistencia de otro par de pinzas Dumont para el posicionamiento del tejido. Una aguja de tungsteno químicamente grabados se pueden utilizar para la manipulación más fina si es necesario. </li><li> Todas las disecciones bien se llevan a cabo con un aumento de ~ 5-8x en una Olympus SZX16 microscopio equipado con un objetivo 1X o equivalente. </li><li> Mantener los embriones en un medio de E3 en una mesa de laboratorio incubadora a 28 ° C al lado del microscopio para el acceso fácil embrión durante la disección. </li><li> La platina del microscopio se calienta a 28 ° C con una placa térmica para reducir al mínimo la influencia de la fluctuación de la temperatura sobre la expresión génica. </li></ul><ol><li> La transferencia de un embrión en una etapa de desarrollo específicas para la solución de Ringer en un Falcon 60 X 15 mm placa de cultivo preparado como se describe en la Parte 1 # 3. </li><li> Le cortó la cabeza con la parte del tronco anterior rápidamente del cuerpo. </li><li> Pin el extremo posterior de este tejido en la placa de cultivo con las pinzas de la asistencia. </li><li> Abrir la cabeza en la parte dorsal a partir de la frente anterior. </li><li> Retire el cerebro de manera que la cara medial de los ojos está expuesto y es hacia arriba para otras manipulaciones. </li></ol> Parte 3A: la disección de una retina <ol><li> Preparar el embrión como se describe en la Parte 2. </li><li> Con cuidado, cepillo de la RPE expuestos en la parte media del globo ocular que es hacia arriba por la punta de la pinza hasta que una pequeña abertura en la retina se ve. </li><li> Continuar con el cepillado y el peeling de acción hasta el lado medial de la retina es casi todo lo expuesto. Evitar arañazos y golpes en la retina expuestos. </li><li> Para quitar el RPE lateral en la retina que se enfrenta ahora a la baja, el enfoque y el cepillo que en un ángulo de aproximadamente 45 ° de la superficie de la placa de cultivo. </li><li> Quitar el EPR que se adjunta relativamente firme a la ora serrata fijando la porción desprendida del EPR a la cultura placa para la disección, y luego levante suavemente la retina. </li><li> Rollo de la retina en la parte inferior de la placa de cultivo para limpiar el RPE residual. <ol class="lalpha"><li> Nos hemos dado cuenta de que este especial de poliestireno Falcon placa de cultivo tiene una adherencia preferencial de RPE durante aproximadamente 20 minutos una vez que un embrión es aplastado. Esta propiedad se utiliza para la eliminación de los restos de RPE. Sin embargo, las células de la retina se adhieren a la superficie, en menor medida, lo que puede ser inspeccionado de cerca con una lupa de alta. Uno tiene que encontrar un equilibrio entre la integridad de la eliminación del EPR y la integridad de la retina. </li><li> La lente con frecuencia se adhiere a la placa de cultivo y se separa de la retina durante el proceso de laminación. En ocasiones, es necesario separar la lente de una aguja de tungsteno grabado con una acción de remolino en la superficie de la lente. </li></ol></li><li> Estos procedimientos pueden eliminar con éxito RPE de la retina sin comprometer la integridad de los tejidos. Esto se indica mediante una buena morfología general (Figura 1 B y B &#39;) y la histología (Figura 1 B &quot;), la flecha, en particular, la preservación de la matriz extracelular entre la capa de fotorreceptores y RPE es excepcional (fig. 1B.&quot;; compara con la histología de todo el embrión (Figura 1 &quot;)). </li></ol> 3B parte: RPE-adjunto disección de la retina 3 <ol><li> Preparar el embrión como se describe en la Parte 2. </li><li> Pin de la cabeza a la placa de cultivo por las pinzas de asistente. Levantar los ojos suavemente desde la parte lateral y posterior despliegue de la cara anterior. <ol class="lalpha"><li> La coroides y presunto tejido escleral en el exterior de la capa de RPE se unen relativamente bien a la piel y puede ser en su mayoría se quitó rodando los ojos con cuidado para la cara anterior. </li></ol></li><li> Retire el objetivo con una aguja de tungsteno después de la parte lateral del ojo está expuesta y cuando el ojo está aún en la piel. </li><li> Estos procedimientos con éxito puede preservar la capa de RPE conjunto con la retina. Coroides presuntivo y tejido escleral puede ser retirado en gran parte (Figura 1 C, &quot;C y C&quot;). </li></ol> Parte 4: recolección de muestras de tejido para el trabajo de ARN <ol><li> Las muestras disecadas se pueden recoger en TRIzol en un tubo de microcentrífuga de RNasa libre para abajo caracterización de ARN como se describe antes del 1. </li></ol> Resultados representante <img src="/files/ftp_upload/2028/2028fig1.jpg" alt="Figura 1" /> Figura 1. (A) y lateral (A) vista dorsal de una cabeza de larvas de pez cebra a las 52 HPF antes de la disección. (A &quot;) El apartado correspondiente histológico de la cabeza de larvas en (A) y (A &#39;). (B) y lateral (B) vista dorsal de la retina diseccionado en 54 HPF. La superficie de la retina estaba intacto, tanto lateral y puntos de vista dorsal. (B &quot;) En la sección correspondiente histológico de la retina disecado en (B) y (B &#39;). La estructura de la retina y la retina de laminación estaba intacto. En particular, la matriz extracelular entre la capa de fotorreceptores y RPE (A &quot;, las flechas) estaba bien conservado en la retina disecados (B&quot;, las flechas). (C) y lateral (C &#39;) vista medial de la disección RPE-adjunto retina en 52 HPF. RPE capa estaba intacto y continuo, que también se indica por el corte histológico de los tejidos disecados (C &quot;). El área blanca en C &#39;es el nervio óptico (flecha). Por histología, las muestras de tejido fueron recogidos y fijados en el 4% paraformaldehído. plástico inclusión y corte de estas muestras se realizaron como se describe 3. Barra de escala = 50 micras.

<ol>
	<li>Leung, Y. F., Dowling, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+expression+profiling+of+zebrafish+embryonic+retina.">Gene expression profiling of zebrafish embryonic retina.</a> Zebrafish. 2, 269-283 (2005).</li><li>Leung, Y. F., Ma, P., Link, B. A., Dowling, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factorial+microarray+analysis+of+zebrafish+retinal+development.">Factorial microarray analysis of zebrafish retinal development.</a> Proc Natl Acad Sci U S A. 105, 12909-12914 (2008).</li><li>Leung, Y. F., Ma, P., Dowling, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+expression+profiling+of+zebrafish+embryonic+retinal+pigment+epithelium+in+vivo.">Gene expression profiling of zebrafish embryonic retinal pigment epithelium in vivo.</a> Invest Ophthalmol Vis Sci. 48, 881-890 (2007).</li><li>Nusslein-Volhard, C., Dahm, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Zebrafish : a practical approach. , (2002).</li><li>Westerfield, 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+zebrafish+book+:+a+guide+for+the+laboratory+use+of+zebrafish+(Danio+rerio).">The zebrafish book : a guide for the laboratory use of zebrafish (Danio rerio).</a> , (2000).</li><li>Kimmel, C. B., Ballard, W. W., Kimmel, S. R., Ullmann, B., Schilling, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stages+of+embryonic+development+of+the+zebrafish.">Stages of embryonic development of the zebrafish.</a> Dev Dyn. 203, 253-310 (1995).</li><li>Fadool, J. M., Dowling, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zebrafish:+a+model+system+for+the+study+of+eye+genetics.">Zebrafish: a model system for the study of eye genetics.</a> Prog Retin Eye Res. 27, 89-110 (2008).</li></ol>

Los experimentos con animales se realizaron de acuerdo con las directrices y normas establecidas por Cuidado de Animales de Purdue y el empleo.

Microdisección de los tejidos del ojo de pez cebra puede efectivamente obtener la retina intacta y las retinas de RPE-adjunto. Esto ayuda considerablemente los estudios de expresión pertenecientes a un tejido ocular específico (es decir, la retina o RPE). De hecho, hemos utilizado con éxito estos procedimientos para obtener los perfiles de expresión de ARN de toda la retina y el EPR 1 3. La utilidad de estos perfiles es apoyado fuertemente por nuestra reciente identificación de las vías y las familias ...

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<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>Cordless pestle motor</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>47747-370</td>
<td>&nbsp;</td>
<tr>
<td>DC power supply</td>
<td>&nbsp;</td>
<td>Lascar</td>
<td>PSU130</td>
<td>Any DC supply would work. The specific voltage of a different machine will need further optimization.</td>
</tr>
<tr>
<td>Disposable pestle &amp; microtube, 1.5 mL (DNase, RNase and pyrogen-free)</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>47747-366</td>
<td>These are used for tissue collection in TRIzol for expression analysis.</td>
</tr>
<tr>
<td>Dumont #5 forceps, Tips: 0.05 x 0.01mm, Inox</td>
<td>&nbsp;</td>
<td>World Precision Instruments</td>
<td>500341</td>
<td>Fine tip dimension is desirable but is not inflexible, as one may need to sharpen the tip from time to time.</td>
</tr>
<tr>
<td>Dumont #5SF forceps, Tips: 0.025 x 0.005mm, Inox</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11252-00</td>
<td>Fine tip dimension is desirable but is not inflexible, as one may need to sharpen the tip from time to time.</td>
</tr>
<tr>
<td>Falcon polystyrene culture plates, 60 X 15 mm</td>
<td>&nbsp;</td>
<td>BD Biosciences</td>
<td>351007</td>
<td>These plates are used as dissection plates.</td>
</tr>
<tr>
<td>Olympus SZX16 Stereomicroscope</td>
<td>&nbsp;</td>
<td>Olympus</td>
<td>SZX16</td>
<td>Any stereomicroscope would work. We used Leica stereomicroscope in previous studies1-3 without any issues. We also use the 1X objective exclusively for the dissection even though we have a 2X objective installed. </td>
</tr>
<tr>
<td>Sharpening stone</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>29008-01</td>
<td>Use this to sharpen the tip of the forceps if necessary</td>
</tr>
<tr>
<td>Thermo plate</td>
<td>&nbsp;</td>
<td>Tokai Hit</td>
<td>MATS-U55SZX2B</td>
<td>This is used to maintain the temperature of the tissue throughout dissection and minimize the influence of temperature fluctuation on gene expression. We also put the whole microscope in an environmentally controlled room at 28&deg;C during dissection in previous studies1-3 with good success.</td>
</tr>
<tr>
<td>Trizol, 100 mL</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>15596-026</td>
<td>&nbsp;</td>
<tr>
<td>tungsten wire, 0.015 inch diameter</td>
<td>&nbsp;</td>
<td>World Precision Instruments</td>
<td>TGW1510</td>
<td>&nbsp;</td>
<tr>
<td>Wooden Applicator</td>
<td>&nbsp;</td>
<td>Puritan</td>
<td>807</td>
<td>This is used for holding the chemically-etched tungsten needle.</td>
</tr>		</tbody>
		</table>
		</div>

microdissection of zebrafish embryonic eye tissues

Pez cebra es un modelo animal popular para la investigación sobre el desarrollo del ojo, debido a su rápida<em&gt; Ex utero</em&gt; El desarrollo y la fecundidad buena. A los 3 días después de la fertilización (dpf), las larvas se mostrará la primera respuesta visual. Muchos genes se han identificado para el control de un desarrollo adecuado de los ojos, pero estamos lejos de una comprensión completa de la arquitectura genética subyacente. Gen de todo el genoma de perfiles de expresión es una herramienta útil para dilucidar red de regulación genética para el desarrollo del ojo. Sin embargo, el pequeño tamaño del ojo de embriones de pez cebra hace que sea difícil obtener los tejidos del ojo intacto y puro para análisis de la expresión. Por ejemplo, la longitud antero-posterior del ojo, entre el día 2 y 3 es de sólo unos 200 a 300 micras, mientras que el diámetro de la lente es m menos de 100. Además, el epitelio pigmentario retiniano (EPR) que subyacen a la retina es un epitelio de una sola capa. Mientras que los perfiles de expresión genética se puede obtener de todo el embrión, que no representan con precisión la expresión de estos tejidos. Por lo tanto el tejido puro debe ser obtenido por un perfil de expresión génica con éxito el desarrollo del ojo. Para solucionar este problema, hemos desarrollado un enfoque para microdissect retina intacta y la retina con el EPR adjunto de fdd 1-3, que abarcan las principales etapas de la morfogénesis del ojo. Todos los procedimientos se puede hacer con unas pinzas finas y suministros generales de laboratorio con microscopios estereoscópicos estándar. Para la disección de la retina, el EPR de una sola capa se elimina y se quitó el cepillo de acción y la adhesión preferencial de los restos del EPR a la superficie de la placa de cultivo para la disección. Para RPE-adjunta la disección de retina, la adhesión de RPE de la placa de la disección se produce antes de la disección a fin de que el EPR puede ser conservado en su totalidad con la retina. Una acción de elevación cuidadosa de este tejido permite la separación de la coroides y la esclerótica presunto. La lente se puede quitar en ambos casos por una aguja de tungsteno grabada químicamente. En resumen, nuestro enfoque puede obtener tejidos intactos los ojos y ha sido utilizado con éxito para el estudio de tejidos específicos perfiles de expresión de la retina del pez cebra<sup&gt; 1, 2</sup&gt; Y el epitelio pigmentario de la retina<sup&gt; 3</sup&gt;.

Watch this Scientific Journal Video about Microdissection of Zebrafish Embryonic Eye Tissues at JoVE.com

Microdissection of Zebrafish Embryonic Eye Tissues

Este artículo describe un método para microdissect retinas del pez cebra con y sin epitelio pigmentario de la retina adjunta, de uno a tres embriones postfertilización días.

Microdisección de los tejidos del ojo de pez cebra embrionarias

Zebrafish is a popular animal model for research on eye development because of its rapid ex utero development and good fecundity. By 3 days post ...

microdissection-of-zebrafish-embryonic-eye-tissues

Research

JoVE Journal

Biology

16.0K vistas.  Purdue University. Este artículo describe un método para microdissect retinas del pez cebra con y sin epitelio pigmentario de la retina adjunta, de uno a tres embriones postfertilización días.

Video: Microdissection of Zebrafish Embryonic Eye Tissues

Laser Capture Microdissection of Mammalian Tissue

Laser capture microscopy, also known as laser microdissection (LMD), enables the user to isolate small numbers of cells or tissues from frozen or formalin-fixed, paraffin-embedded tissue sections. LMD techniques rely on a thermo labile membrane placed either on top of, or underneath, the tissue section. In one method, focused laser energy is used to melt the membrane onto the underlying cells, which can then be lifted out of the tissue section. In the other, the laser energy vaporizes the foil along a path "drawn" on the tissue, allowing the selected cells to fall into a collection device. Each technique allows the selection of cells with a minimum resolution of several microns. DNA, RNA, protein, and lipid samples may be isolated and analyzed from micro-dissected samples. In this video, we demonstrate the use of the Leica AS-LMD laser microdissection instrument in seven segments, including an introduction to the principles of LMD, initializing the instrument for use, general considerations for sample preparation, mounting the specimen and setting up capture tubes, aligning the microscope, adjusting the capture controls, and capturing tissue specimens. Laser-capture micro-dissection enables the investigator to isolate samples of pure cell populations as small as a few cell-equivalents. This allows the analysis of cells of interest that are free of neighboring contaminants, which may confound experimental results.

Láser microdisección de captura de tejidos de mamíferos

Laser capture microscopy, also known as laser microdissection (LMD), enables the user to isolate small numbers of cells or tissues from frozen or ...

Investigación

Biología

Live Imaging of the Zebrafish Embryonic Brain by Confocal Microscopy

In this video, we demonstrate the method our lab has developed to analyze the cell shape changes and rearrangements required to bend and fold the developing zebrafish brain (Gutzman et al, 2008). Such analysis affords a new understanding of the underlying cell biology required for development of the 3D structure of the vertebrate brain, and significantly increases our ability to study neural tube morphogenesis. The embryonic zebrafish brain is shaped beginning at 18 hours post fertilization (hpf) as the ventricles within the neuroepithelium inflate. By 24 hpf, the initial steps of neural tube morphogenesis are complete. Using the method described here, embryos at the one cell stage are injected with mRNA encoding membrane-targeted green fluorescent protein (memGFP). After injection and incubation, the embryo, now between 18 and 24 hpf, is mounted, inverted, in agarose and imaged by confocal microscopy. Notably, the zebrafish embryo is transparent making it an ideal system for fluorescent imaging. While our analyses have focused on the midbrain-hindbrain boundary and the hindbrain, this method could be extended for analysis of any region in the zebrafish to a depth of 
80-100 &mu;m.

In this video, we demonstrate a method by which to analyze the developing vertebrate brain in live zebrafish embryos at single cell resolution by confocal microscopy. This includes the method by which we inject the single-cell zebrafish embryo and subsequently mount and image the developing brain.

Imágenes en vivo del cerebro del embrión de pez cebra mediante microscopía confocal

In this video, we demonstrate the method our lab has developed to analyze the cell shape changes and rearrangements required to bend and fold the ...

Lens Transplantation in Zebrafish and its Application in the Analysis of Eye Mutants

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development can be addressed. The zebrafish is useful for genetic studies due to several advantageous characteristics, including small size, high fecundity, short lifecycle, and ease of care. Lens development occurs rapidly in zebrafish. By 72 hpf, the zebrafish lens is functionally mature [3]. Abundant genetic and molecular resources are available to support research in zebrafish. In addition, the similarity of the zebrafish eye to those of other vertebrates provides basis for its use as an excellent animal model of human defects[4-7]. Several zebrafish mutants exhibit lens abnormalities, including high levels of cell death, which in some cases leads to a complete degeneration of lens tissues [8]. To determine whether lens abnormalities are due to intrinsic causes or to defective interactions with the surrounding tissues, transplantation of a mutant lens into a wild-type eye is performed. Using fire-polished metal needles, mutant or wild-type lenses are carefully dissected from the donor animal, and transferred into the host. To distinguish wild-type and mutant tissues, a transgenic line is used as the donor. This line expresses membrane-bound GFP in all tissues, including the lens. This transplantation technique is an essential tool in the studies of zebrafish lens mutants.

Lens development involves interactions with other tissues. Several zebrafish eye mutants are characterized by an abnormally small lens size. Here we demonstrate a lens transplantation experiment to determine whether this phenotype is due to intrinsic causes or defective interactions with tissues that surround the lens.

Trasplante de lentes en el pez cebra y su aplicación en el análisis de mutantes de ojos

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development ...

Tissue Targeted Embryonic Chimeras: Zebrafish Gastrula Cell Transplantation

Certain fundamental questions in the field of developmental biology can only be answered when cells are placed in novel environments or when small groups of cells in a larger context are altered.  Watching how one cell interacts with and behaves in a unique environment is essential to characterizing cell functions.  Determining how the localized misexpression of a specific protein influences surrounding cells provides insightful information on the roles that protein plays in a variety of developmental processes.  Our lab uses the zebrafish model system to uniquely combine genetic approaches with classical transplantation techniques to generate genotypic or phenotypic chimeras.  We study neuron-glial cell interactions during the formation of forebrain commissures in zebrafish. This video describes a method that allows our lab to investigate the role of astroglial populations in the diencephalon and the roles of specific guidance cues that influence projecting axons as they cross the midline. Due to their transparency zebrafish embryos are ideal models for this type of ectopic cell placement or localized gene misexpression. Tracking transplanted cells can be accomplished using a vital dye or a transgenic fish line expressing a fluorescent protein. We demonstrate here how to prepare donor embryos with a vital dye tracer for transplantation, as well as how to extract and transplant cells from one gastrula staged embryo to another.  We present data showing ectopic GFP+ transgenic cells within the forebrain of zebrafish embryos and characterize the location of these cells with respect to forebrain commissures.  In addition, we show laser scanning confocal timelapse microscopy of Alexa 594 labeled cells transplanted into a GFP+ transgenic host embryo.  These data provide evidence that gastrula staged transplantation enables the targeted positioning of ectopic cells to address a variety of questions in Developmental Biology.

Zebrafish cell transplantation enables the combination of genetics and embryology to generate tissue specific chimeras. This video demonstrates gastrula staged cell transplantations that have allowed our lab to investigate the roles of astroglial populations and specific guidance cues during commissure formation in the forebrain.

Tejido diana quimeras embrionarias: pez cebra Gástrula Trasplante de células

Certain fundamental questions in the field of developmental biology can only be answered when cells are placed in novel environments or when small groups ...

RNA Isolation from Embryonic Zebrafish and cDNA Synthesis for Gene Expression Analysis

Many important and complex laboratory procedures require an input of high quality, intact RNA.  A degraded sample or the presence of impurities can lead to disastrous results in downstream experimental applications.  It is therefore, of utmost importance to use solid techniques with numerous safeguards and quality control checks to ensure a superior sample.  Herein, we detail a protocol to isolate total RNA from whole zebrafish embryos using a commercially available chemical denaturant and subsequent cleanup to remove traces of DNA and impurities using a commercial RNA isolation kit. As RNA is relatively unstable and easily prone to cleavage by RNAses, most protocols assay gene expression using a cDNA product that is directly synthesized from an RNA template. We detail a procedure to convert RNA into the more stable cDNA product using a commercially available kit. Throughout these procedures there are numerous quality control checks to ensure that the sample is not degraded or contaminated.  The end product of these protocols is cDNA that is suitable for microarray analysis, RT-PCR or long-term storage.    

The isolation of high quality, intact RNA is an essential step in many laboratory protocols. Here, we demonstrate RNA extraction from whole zebrafish embryos and cDNA synthesis for subsequent application in various experimental procedures including gene expression microarray analysis.

Aislamiento del ARN de síntesis embrionarias pez cebra y el cDNA de análisis de expresión génica

Many important and complex laboratory procedures require an input of high quality, intact RNA.  A degraded sample or the presence of impurities can lead ...

Microdissection of Black Widow Spider Silk-producing Glands

Modern spiders spin high-performance silk fibers with a broad range of biological functions, including locomotion, prey capture and protection of developing offspring 1,2. Spiders accomplish these tasks by spinning several distinct fiber types that have diverse mechanical properties. Such specialization of fiber types has occurred through the evolution of different silk-producing glands, which function as small biofactories. These biofactories manufacture and store large quantities of silk proteins for fiber production. Through a complex series of biochemical events, these silk proteins are converted from a liquid into a solid material upon extrusion.
Mechanical studies have demonstrated that spider silks are stronger than high-tensile steel 3. Analyses to understand the relationship between the structure and function of spider silk threads have revealed that spider silk consists largely of proteins, or fibroins, that have block repeats within their protein sequences 4. Common molecular signatures that contribute to the incredible tensile strength and extensibility of spider silks are being unraveled through the analyses of translated silk cDNAs. Given the extraordinary material properties of spider silks, research labs across the globe are racing to understand and mimic the spinning process to produce synthetic silk fibers for commercial, military and industrial applications. One of the main challenges to spinning artificial spider silk in the research lab involves a complete understanding of the biochemical processes that occur during extrusion of the fibers from the silk-producing glands.
Here we present a method for the isolation of the seven different silk-producing glands from the cobweaving black widow spider, which includes the major and minor ampullate glands [manufactures dragline and scaffolding silk] 5,6, tubuliform [synthesizes egg case silk] 7,8, flagelliform [unknown function in cob-weavers], aggregate [makes glue silk], aciniform [synthesizes prey wrapping and egg case threads] 9 and pyriform [produces attachment disc silk] 10. This approach is based upon anesthetizing the spider with carbon dioxide gas, subsequent separation of the cephalothorax from the abdomen, and microdissection of the abdomen to obtain the silk-producing glands. Following the separation of the different silk-producing glands, these tissues can be used to retrieve different macromolecules for distinct biochemical analyses, including quantitative real-time PCR, northern- and western blotting, mass spectrometry (MS or MS/MS) analyses to identify new silk protein sequences, search for proteins that participate in the silk assembly pathway, or use the intact tissue for cell culture or histological experiments.

Here we describe an efficient strategy to remove the silk-producing glands from the abdomen of female black widow spiders. This procedure allows the rapid isolation of the seven distinct silk-producing glands in a highly purified fashion, an important process for investigators studying spider silk production and fiber assembly.

Microdisección de Negro Araña Viuda producción de las glándulas de seda

Modern spiders spin high-performance silk fibers with a broad range of biological functions, including locomotion, prey capture and protection of ...

Immunostaining of Dissected Zebrafish Embryonic Heart

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics 1,2. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects 3. The expression of any gene can be manipulated via morpholino technology or RNA injection 4. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis 5. 
Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue 6. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. 
 Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. 
Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals.

A rapid way to conduct immunostaining of zebrafish embryonic heart is described. Compared to the whole mount immunostaining approach, this method dramatically increases the penetration of the antibodies, which allows obtaining high resolution images that reveal cellular/subcellular structures in the heart within a much reduced processing time.

Inmunotinción de Disección del corazón embrionario de pez cebra

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology ...

In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina

Many devastating inherited eye diseases result in progressive and irreversible blindness because humans cannot regenerate dying or diseased retinal neurons. In contrast, the adult zebrafish retina possesses the robust ability to spontaneously regenerate any neuronal class that is lost in a variety of different retinal damage models, including retinal puncture, chemical ablation, concentrated high temperature, and intense light treatment 1-8. Our lab extensively characterized regeneration of photoreceptors following constant intense light treatment and inner retinal neurons after intravitreal ouabain injection 2, 5, 9. In all cases, resident M&uuml;ller glia re-enter the cell cycle to produce neuronal progenitors, which continue to proliferate and migrate to the proper retinal layer, where they differentiate into the deficient neurons. 
	We characterized five different stages during regeneration of the light-damaged retina that were highlighted by specific cellular responses. We identified several differentially expressed genes at each stage of retinal regeneration by mRNA microarray analysis 10. Many of these genes are also critical for ocular development. To test the role of each candidate gene/protein during retinal regeneration, we needed to develop a method to conditionally limit the expression of a candidate protein only at times during regeneration of the adult retina. 
	Morpholino oligos are widely used to study loss of function of specific proteins during the development of zebrafish, Xenopus, chick, mouse, and tumors in human xenografts 11-14. These modified oligos basepair with complementary RNA sequence to either block the splicing or translation of the target RNA. Morpholinos are stable in the cell and can eliminate or "knockdown" protein expression for three to five days 12. 
	Here, we describe a method to efficiently knockdown target protein expression in the adult zebrafish retina. This method employs lissamine-tagged antisense morpholinos that are injected into the vitreous of the adult zebrafish eye. Using electrode forceps, the morpholino is then electroporated into all the cell types of the dorsal and central retina. Lissamine provides the charge on the morpholino for electroporation and can be visualized to assess the presence of the morpholino in the retinal cells. 
	Conditional knockdown in the retina can be used to examine the role of specific proteins at different times during regeneration. Additionally, this approach can be used to study the role of specific proteins in the undamaged retina, in such processes as visual transduction and visual processing in second order neurons.

In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina

A method to conditionally knockdown a target protein&#x2019;s expression in the adult zebrafish retina is described, which involves intravitreally injecting antisense morpholinos and electroporating them into the retina. The resulting protein is knocked down for several days, which allows testing the protein&#x2019;s role in the regenerating or intact retina.

En electroporación in vivo de Morpholinos en la retina de pez cebra adultos

Many devastating inherited eye diseases result in progressive and irreversible blindness because humans cannot regenerate dying or diseased retinal ...

A System for ex vivo Culturing of Embryonic Pancreas

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

A System for ex vivo Culturing of Embryonic Pancreas

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

Un sistema para la<em&gt; Ex vivo</em&gt; Cultivo de páncreas embrionario

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

Laser-inflicted Injury of Zebrafish Embryonic Skeletal Muscle

Various experimental approaches have been used in mouse to induce muscle injury with the aim to study muscle regeneration, including myotoxin injections (bupivacaine, cardiotoxin or notexin), muscle transplantations (denervation-devascularization induced regeneration), intensive exercise, but also murine muscular dystrophy models such as the mdx mouse (for a review of these approaches see 1). In zebrafish, genetic approaches include mutants that exhibit muscular dystrophy phenotypes (such as runzel2 or sapje3) and antisense oligonucleotide morpholinos that block the expression of dystrophy-associated genes4. Besides, chemical approaches are also possible, e.g. with Galanthamine, a chemical compound inhibiting acetylcholinesterase, thereby resulting in hypercontraction, which eventually leads to muscular dystrophy5. However, genetic and pharmacological approaches generally affect all muscles within an individual, whereas the extent of physically inflicted injuries are more easily controlled spatially and temporally1. Localized physical injury allows the assessment of contralateral muscle as an internal control. Indeed, we recently used laser-mediated cell ablation to study skeletal muscle regeneration in the zebrafish embryo6, while another group recently reported the use of a two-photon laser (822 nm) to damage very locally the plasma membrane of individual embryonic zebrafish muscle cells7.
Here, we report a method for using the micropoint laser (Andor Technology) for skeletal muscle cell injury in the zebrafish embryo. The micropoint laser is a high energy laser which is suitable for targeted cell ablation at a wavelength of 435 nm. The laser is connected to a microscope (in our setup, an optical microscope from Zeiss) in such a way that the microscope can be used at the same time for focusing the laser light onto the sample and for visualizing the effects of the wounding (brightfield or fluorescence). The parameters for controlling laser pulses include wavelength, intensity, and number of pulses.
Due to its transparency and external embryonic development, the zebrafish embryo is highly amenable for both laser-induced injury and for studying the subsequent recovery. Between 1 and 2 days post-fertilization, somitic skeletal muscle cells progressively undergo maturation from anterior to posterior due to the progression of somitogenesis from the trunk to the tail8, 9. At these stages, embryos spontaneously twitch and initiate swimming. The zebrafish has recently been recognized as an important vertebrate model organism for the study of tissue regeneration, as many types of tissues (cardiac, neuronal, vascular etc.) can be regenerated after injury in the adult zebrafish10, 11.

The method presented here comprises the precise injury of live zebrafish embryos with high-energy laser pulses and the subsequent analysis of these injuries and their recovery with time. We also show how genetically labeled single or groups of skeletal muscle cells can be tracked during and after laser light induced damage.

Laser-infligido lesiones de músculo esquelético embrionario de pez cebra

Various experimental approaches have been used in mouse to induce muscle injury with the aim to study muscle regeneration, including myotoxin injections ...