FIPE / HCPA - Fundo de Incentivo a Pesquisa e Eventos CAPES - <a href="http://www.capes.gov.br/">Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior</a>

1. Protocolo de Texto <ol><li> Antes de la recogida de sangre de pez cebra, es necesario para preparar el agua anestésico. Verter ~ 200 ml de agua del acuario en un recipiente con una capacidad de 500-ml. Añadir ~ 200 g de trozos de hielo. La temperatura debe ser de aproximadamente 4 ° C. Como los trozos de hielo se derriten, será necesario añadir más cubos de hielo para mantener una temperatura constante de alrededor de 4 ° C. </li><li> Cuando el agua anestésico está listo, preparar los materiales necesarios para la recogida de sangre. Ponga un extremo de baja retención en una pipeta P20 y salir de la pipeta en el que se puede acceder fácilmente. No permita que la punta de la pipeta en contacto con cualquier fuente de contaminación. </li><li> Cubrir una placa de Petri con un pedazo de gasa seca. Una hoja de acero y otro trozo de gasa debe ser colocado en un lugar fácilmente accesible. </li><li> Una centrífuga adaptado para tubos de plástico se necesitará. </li><li> Cuando los materiales antes mencionados se preparan, la captura del pez cebra primero en ser anestesiado el ingenioja red de pesca y lo liberan en el agua que ha sido preparado para la anestesia. El pez cebra requieren 3-6 s en agua fría para ser anestesiados, dependiendo de los peces. Mantenga el pez en el agua fría hasta que ya no responde a los estímulos externos. </li><li> Uso de la red de pesca, coloque el pescado anestesiado en una pieza preparada de gasa, dejando la cola fuera de la gasa. Doble la gasa sobre la cabeza del pez y el cuerpo dejando fuera sólo su cola. Poner el pescado cubierto con la gasa sobre la placa de Petri. </li><li> Utilice la hoja de acero para hacer una incisión en diagonal justo entre la aleta anal y la aleta caudal. La sangre empieza a salir. En este punto, es necesario trabajar con rapidez. </li><li> Con cuidado aspirar la sangre que sale con la pipeta P20 (pre-cargado con una punta baja retención). La cantidad de sangre que puede recogerse depende del tamaño de los peces, y en qué medida en que fue anestesiado correctamente. Por lo general, varía desde 5 hasta 20 l. Cuando la sangre deja de coming cabo, suavemente transferir la sangre aspirado en un tubo. </li><li> Para evitar la hemólisis, es crítico que el tubo con la sangre en ella ser manejado con mucho cuidado, sin ningún movimiento drástico hasta que se coloca en la centrifugadora. </li><li> Para evitar la hemólisis, también es importante que la muestra de sangre se asegura en la centrífuga dentro de los 10 minutos de recogida de sangre. </li><li> Si es necesario, es posible combinar la sangre de más de un animal, haciendo una piscina. Las muestras combinadas funcionará bien siempre y cuando la demora entre la recogida de sangre de los peces primero y centrifugación no exceda de 10 minutos. </li><li> Cuando la recogida de sangre se hace, centrifugar la sangre durante 10 minutos a 0,5 g (centrífuga Eppendorf 5415D). </li><li> Tras la centrifugación, el suero se presenta en la capa superior del tubo. Con una pipeta, aspire el suero, asegurándose de obtener sólo el suero, manteniendo las dos capas bien dividida y estable. </li><li> Transferir el suero a un microtubo nuevo yestá listo para ser utilizado en los análisis bioquímicos. El suero puede ser almacenado en hielo mientras se espera para iniciar los análisis bioquímicos. </li><li> Si el suero no se utiliza inmediatamente, se puede congelar a -18 ° C hasta aproximadamente 3 meses. </li></ol> 2. Los resultados representativos Fue posible recoger 5 a 20 l de sangre entera de cada pez lo que representa la sangre incluso 4 veces más que las técnicas descritas previamente (Tabla 2). El análisis bioquímico del colesterol total, HDL-colesterol, LDL-colesterol y triglicéridos se realizaron después de la recogida de sangre utilizando esta técnica. Dos grupos de ambos sexos, los peces se mantuvieron en ayunas durante 24 horas antes de la extracción de sangre para evitar la interferencia de consumo de alimentos. Los análisis se realizaron con las pruebas a pequeña escala colorimétrica (Labtest Diagnóstica SA, Brasil) para los análisis de colesterol total y triglicéridos, 3 l de suero se utiliza. Para el colesterol LDL y HDL-colesterolanálisis, 4 l, y 10 l de suero se utilizaron, respectivamente. Estos análisis se realizaron en muestras combinadas de 10 pez cebra por muestra. Los niveles séricos lipídicos fueron comparados entre los peces que se accede a sus propios huevos y los que, en un acuario de fondo cubierto, no tienen acceso a sus propios huevos durante un período experimental de 2 semanas. Análisis de suero mostraron que los niveles séricos de colesterol total (con huevos 362 ± 42 mg / dl y sin huevos 357 ± 13 mg / dl), HDL-colesterol (con huevos 91,22 ± 1,79 mg / dl y sin huevos 72,14 ± 2,89 mg / dl) y colesterol LDL (con huevos de 55,68 ± 10,88 mg / dl y sin huevos 44,18 ± 9,84 mg / dL) no difirió significativamente entre los grupos. Sin embargo, los niveles de triglicéridos fueron significativamente menores en el grupo experimental (sin huevos 292 ± 64 mg / dl) que en el grupo control (con huevos de 457 ± 25 mg / dL, p = 0,03). <table border="1" ><tbody><tr><td> &amp; Nbsp; </td><td> Con el acceso a los huevos </td><td> Sin acceso a los huevos </td></tr><tr><td> El colesterol total (mg / dL) </td><td> 362,82 ± 73,11 </td><td> 357,69 ± 23,08 </td></tr><tr><td> LDL - Colesterol (mg / dL) </td><td> 55,69 ± 18,84 </td><td> 44,19 ± 17,05 </td></tr><tr><td> HDL - Colesterol (mg / dL) </td><td> 91,23 ± 3,11 </td><td> 72,14 ± 5,01 </td></tr><tr><td> Los triglicéridos (mg / dl) </td><td> 457,64 ± 43,78 * </td><td> 292,36 ± 111,28 </td></tr></tbody></table> Tabla 1. Niveles séricos de colesterol y triglicéridos en ambos grupos estudiados (con acceso a los huevos y sin acceso a los huevos), expresado en media ± desviación estándar. * Estadísticamente significativo (p = 0,03). Prueba t de Student. <table border="1"><tbody><tr><td> Aut.<html> hors </td><td> Lugar de la incisión </td><td> Cosecha método </td><td> Anestesia </td><td> La cantidad de sangre recogida </td></tr><tr><td> Jagadeeswaran et. al., 1999 Murtha et al., 2003 </td><td> Posterior disección de las microempresas y las de la aleta dorsal </td><td> Micropipeta </td><td> No se menciona MS222 3% en agua fría </td><td> 1 un 5 l 5 un 10 l </td></tr><tr><td> Eames et al., 2010 </td><td> Decapitación </td><td> Micro capilares del tubo </td><td> MS222 0,02% 28 ° C del agua </td><td> 5 un 10 l </td></tr><tr><td> Estudio Actual </td><td> La incisión entre la aleta anal y la aleta caudal </td><td> Micropipetas y puntas de baja retención </td><td> De agua y pedazos de hielo </td><td> 5 un 20 l </td></tr></tbody></table>e_content &quot;&gt; Tabla 2. Comparación entre las técnicas de recogida de sangre descritos anteriormente y la descrita en el presente estudio.

<ol>
	<li>Schneider, A. C. R., dos Santo, J. L., Porawski, M., Schaefer, P. G., Maurer, R. L., Matte, U., da Silveira, T. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implementa&#231;&#227;o+de+um+novo+modelo+de+experimenta&#231;&#227;o+animal+Zebrafish.">Implementa&#231;&#227;o de um novo modelo de experimenta&#231;&#227;o animal Zebrafish.</a> Rev. HCPA. 29, 100-103 (2009).</li><li>Briggs, J. P. <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:+a+new+model+organism+for+integrative+physiology.">The zebrafish: a new model organism for integrative physiology.</a> Am. J. Physiol. Regulatory Integrative Comp. Physiol. 282, 3-9 (2002).</li><li>Menke, A. L., Sptsbergen, J. M., Wolterbeek, A. P. M., Woutersen, 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=Normal+anatomy+and+histology+of+adult+Zebrafish.">Normal anatomy and histology of adult Zebrafish.</a> Toxicologic Pathology. 000, 1-16 (2011).</li><li>Murtha, J. M., Qi, W., Keller, E. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hematologic+and+serum+biochemical+values+for+Zebrafish.">Hematologic and serum biochemical values for Zebrafish.</a> Comp. Med. 53, 37-41 (2003).</li><li>Jagadeeswaran, P., Sheehan, J. P., Craig, F. E., Troyer, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+characterization+of+zebrafish+thrombocytes.">Identification and characterization of zebrafish thrombocytes.</a> Br. J. Haematol. 107, 731-738 (1999).</li><li>Jagadeeswaran, P., Sheehan, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+blood+coagulation+in+the+zebrafish.">Analysis of blood coagulation in the zebrafish.</a> Blood Cells Mol. Dis. 25, 239-249 (1999).</li><li>Eames, S. C., Philipson, L. H., Prince, V. E., Kinkel, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+sugar+measurement+in+zebrafish+reveals+dynamics+of+glucose+homeostasis.">Blood sugar measurement in zebrafish reveals dynamics of glucose homeostasis.</a> Zebrafish. 7, 205-213 (2010).</li><li>Kilpatrick, E. S., Rumley, A. G., Rumley, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+haemolysis+on+blood+glucose+meter+measurement.">The effect of haemolysis on blood glucose meter measurement.</a> Diabet. Med. 12, 341-343 (1995).</li><li>Gupta, T., Mullins, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissection+of+Organs+from+the+Adult+Zebrafish.">Dissection of Organs from the Adult Zebrafish.</a> J. Vis. Exp. (37), e1717 (2010).</li><li>Kinkel, M. D., Eames, S. C., Philipson, L. H., Prince, V. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraperitoneal+Injection+into+Adult+Zebrafish.">Intraperitoneal Injection into Adult Zebrafish.</a> J. Vis. Exp. (42), e2126 (2010).</li><li>Pugach, E. K., Li, P., White, R., Zon, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retro-orbital+Injection+in+Adult+Zebrafish.">Retro-orbital Injection in Adult Zebrafish.</a> J. Vis. Exp. (34), e1645 (2009).</li></ol>

No hay conflictos de interés declarado.

Este trabajo presenta una técnica sencilla que permite a más análisis de sangre y suero en experimentos de pez cebra. Esta técnica tiene el potencial de contribuir a los estudios futuros de pez cebra hematológicas que requieren los datos de los parámetros sanguíneos. También debería permitir mayores aplicaciones del pez cebra como un modelo experimental. Esta técnica no requiere habilidades especiales o la aplicación de una técnica precisa. Además, se permite hasta el doble de l...

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios </td></tr><tr><td> Consejos bajos de retención </td><td> Applied Biosystems </td><td> 022493020 </td><td></td></tr><tr><td> Eppendorf Centrífuga 5415D </td><td> Eppendorf </td><td> Suspendido </td><td></td></tr></tbody></table>

blood collection for biochemical analysis in adult zebrafish

El pez cebra se ha utilizado como un modelo animal para estudios de varias enfermedades humanas. Puede servir como una plataforma preclínica potente para los estudios de sucesos moleculares y estrategias terapéuticas, así como para evaluar los mecanismos fisiológicos de unos 1 patologías. Hay relativamente pocas las publicaciones relacionadas con la fisiología del pez cebra adulto de órganos y sistemas 2, que pueden conducir a los investigadores a deducir que las técnicas básicas necesarias para permitir la exploración de los sistemas de pez cebra faltan 3. Hematológicas valores bioquímicos de pez cebra fueron por primera vez en 2003 por Murtha y 4 colegas que empleó una técnica de recogida de sangre descrita por primera vez por Jagadeeswaran y sus colegas en 1999. Brevemente, se recogió sangre a través de una punta de la micropipeta a través de una incisión lateral, aproximadamente 0,3 cm de longitud, en la región de la aorta dorsal 5. Debido a las dimensiones implicadas minuto, estoEs una técnica de alta precisión que requiere un practicante altamente cualificado. La misma técnica fue utilizada por el mismo grupo en otra publicación en ese mismo año 6. En 2010, Eames y sus colegas evaluaron los niveles de glucosa en la sangre enteros en el pez cebra 7. Se tuvo acceso a la sangre mediante la realización de las decapitaciones con unas tijeras y luego insertar un tubo de recogida heparinizado microcapilar en la articulación pectoral. Ellos aluden a la dificultad con la hemólisis que se resolvieron con una temperatura de almacenamiento adecuada basada en el trabajo Kilpatrick et al. 8. Al intentar usar la técnica Jagadeeswaran en nuestro laboratorio, se encontró que era difícil hacer la incisión en el lugar correcto, precisamente como no permitir que una cantidad significativa de sangre que se pierde antes de la recolección se pudo iniciar. Recientemente, Gupta et al. 9 se describe la forma de diseccionar los órganos adultos de pez cebra, la Kinkle et al. 10 se describe cómo llevar a cabo intraperitoninyecciones de EAL, y Pugach et al 11 se describe cómo realizar las inyecciones retro-orbital. Sin embargo, se necesita más trabajo para explorar más a fondo las técnicas básicas para la investigación en el pez cebra. El pequeño tamaño del pez cebra presenta desafíos para los investigadores que lo utilizan como un modelo experimental. Además, dada esta pequeñez de la escala, es importante que las técnicas simples se han desarrollado para permitir a los investigadores a explorar las ventajas del modelo de pez cebra.

Watch this Scientific Journal Video about Blood Collection for Biochemical Analysis in Adult Zebrafish at JoVE.com

Blood Collection for Biochemical Analysis in Adult Zebrafish

Este trabajo presenta una técnica para la recolección de sangre de la aorta dorsal del pez cebra. También proporciona instrucciones para la obtención de suero para uso en los análisis bioquímicos, tales como ensayos para determinar los niveles de colesterol y triglicéridos.

Extracción de sangre para análisis bioquímicos en adultos de pez cebra

The zebrafish has been used as an animal model for studies of several human diseases. It can serve as a powerful preclinical platform for studies of ...

blood-collection-for-biochemical-analysis-in-adult-zebrafish

Research

JoVE Journal

Biology

36.1K vistas.  Centro de Pesquisa Experimental Laboratório de Hepatologia e Gastroenterologia Experimental. Este trabajo presenta una técnica para la recolección de sangre de la aorta dorsal del pez cebra. También proporciona instrucciones para la obtención de suero para uso en los análisis bioquímicos, tales como ensayos para determinar los niveles de colesterol y triglicéridos.

Video: Blood Collection for Biochemical Analysis in Adult Zebrafish

Transplantation of Whole Kidney Marrow in Adult Zebrafish

Hematopoietic stem cells (HSC) are a rare population of pluripotent cells that maintain all the differentiated blood lineages throughout the life of an organism. The functional definition of a HSC is a transplanted cell that has the ability to reconstitute all the blood lineages of an irradiated recipient long term. This designation was established by decades of seminal work in mammalian systems. Using hematopoietic cell transplantation (HCT) and reverse genetic manipulations in the mouse, the underlying regulatory factors of HSC biology are beginning to be unveiled, but are still largely under-explored. Recently, the zebrafish has emerged as a powerful genetic model to study vertebrate hematopoiesis. Establishing HCT in zebrafish will allow scientists to utilize the large-scale genetic and chemical screening methodologies available in zebrafish to reveal novel mechanisms underlying HSC regulation. In this article, we demonstrate a method to perform HCT in adult zebrafish. We show the dissection and preparation of zebrafish whole kidney marrow, the site of adult hematopoiesis in the zebrafish, and the introduction of these donor cells into the circulation of irradiated recipient fish via intracardiac injection. Additionally, we describe the post-transplant care of fish in an "ICU" to increase their long-term health. In general, gentle care of the fish before, during, and after the transplant is critical to increase the number of fish that will survive more than one month following the procedure, which is essential for assessment of long term (&lt;3 month) engraftment. The experimental data used to establish this protocol will be published elsewhere. The establishment of this protocol will allow for the merger of large-scale zebrafish genetics and transplant biology.

In this article, we demonstrate a method to perform HCT in adult zebrafish.

El trasplante de médula del riñón entero en adultos de pez cebra

Hematopoietic stem cells (HSC) are a rare population of pluripotent cells that maintain all the differentiated blood lineages throughout the life of an ...

Investigación

Biología

Zebrafish Brain Ventricle Injection

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved cavities within the brain that are filled with cerebrospinal fluid.  In zebrafish, after neural tube formation, the neuroepithelium undergoes a series of constrictions and folds while it fills with fluid resulting in brain ventricle formation.  In order to understand the process of ventricle formation, and the neuroepithelial shape changes that occur at the same time, we needed a way to visualize the ventricle space in comparison to the brain tissue.  However, the nature of transparent zebrafish embryos makes it difficult to differentiate the tissue from the ventricle space.  Therefore, we developed a brain ventricle injection technique where the ventricle space is filled with a fluorescent dye and imaged by brightfield and fluorescent microscopy.  The brightfield and the fluorescent images are then processed and superimposed in Photoshop.  This technique allows for visualization of the ventricle space with the fluorescent dye, in comparison to the shape of the neuroepithelium in the brightfield image.  Brain ventricle injection in zebrafish can be employed from 18 hours post fertilization through early larval stages.  We have used this technique extensively in our studies of brain ventricle formation and morphogenesis as well as in characterizing brain morphogenesis mutants (1-3).

After neural tube formation, the neuroepithelium constricts and folds while the tube fills with embryonic cerebrospinal fluid (eCSF) to form the embryonic brain ventricles. We developed this ventricle injection technique to better visualize the fluid filled space in contrast to the neuroepithelial shape in a live embryo.

Cerebro del pez cebra ventrículo inyección

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved ...

Retro-orbital Injection in Adult Zebrafish

Drug treatment of whole animals is an essential tool in any model system for pharmacological and chemical genetic studies. Intravenous (IV) injection is often the most effective and noninvasive form of delivery of an agent of interest. In the zebrafish (Danio rerio), IV injection of drugs has long been a challenge because of the small vessel diameter. This has also proved a significant hurdle for the injection of cells during hematopoeitic stem cell transplantation. Historically, injections into the bloodstream were done directly through the heart. However, this intra-cardiac procedure has a very high mortality rate as the heart is often punctured during injection leaving the fish prone to infection, massive blood loss or fatal organ damage. Drawing on our experience with the mouse, we have developed a new injection procedure in the zebrafish in which the injection site is behind the eye and into the retro-orbital venous sinus. This retro-orbital (RO) injection technique has been successfully employed in both the injection of drugs in the adult fish as well as transplantation of whole kidney marrow cells. RO injection has a much lower mortality rate than traditional intra-cardiac injection. Fish that are injected retro-orbitally tend to bleed less following injection and are at a much lower risk of injury to a major organ like the heart. Further, when performed properly, injected cells and/or drugs quickly enter the bloodstream allowing compounds to exert their effect on the whole fish and kidney cells to easily home to their niche. Thus, this new injection technique minimizes mortality while allowing efficient delivery of material into the bloodstream of adult fish. Here we exemplify this technique by retro-orbital injection of Tg(globin:GFP) cells into adult casper fish as well as injection of a red fluorescent dye (dextran, Texas Red ) into adult casper fish. We then visualize successful injections by whole animal fluorescence microscopy.

Here we show how to do retro-orbital injection in adult zebrafish.

Retro-orbital de inyección en adultos de pez cebra

Drug treatment of whole animals is an essential tool in any model system for pharmacological and chemical genetic studies. Intravenous (IV) injection is ...

Intraperitoneal Injection into Adult Zebrafish

A convenient method for chemically treating zebrafish is to introduce the reagent into the tank water, where it will be taken up by the fish. However, this method makes it difficult to know how much reagent is absorbed or taken up per fish. Some experimental questions, particularly those related to metabolic studies, may be better addressed by delivering a defined quantity to each fish, based on weight. Here we present a method for intraperitoneal (IP) injection into adult zebrafish. Injection is into the abdominal cavity, posterior to the pelvic girdle. This procedure is adapted from veterinary methods used for larger fish. It is safe, as we have observed zero mortality. Additionally, we have seen bleeding at the injection site in only 5 out of 127 injections, and in each of those cases the bleeding was brief, lasting several seconds, and the quantity of blood lost was small. Success with this procedure requires gentle handling of the fish through several steps including fasting, weighing, anesthetizing, injection, and recovery. Precautions are required to minimize stress throughout the procedure. Our precautions include using a small injection volume and a 35G needle. We use Cortland salt solution as the vehicle, which is osmotically balanced for freshwater fish. Aeration of the gills is maintained during the injection procedure by first bringing the fish into a surgical plane of anesthesia, which allows slow operculum movements, and second, by holding the fish in a trough within a water-saturated sponge during the injection itself. We demonstrate the utility of IP injection by injecting glucose and monitoring the rise in blood glucose level and its subsequent return to normal. As stress is known to increase blood glucose in teleost fish, we compare blood glucose levels in vehicle-injected and non-injected adults and show that the procedure does not cause a significant rise in blood glucose.

We demonstrate intraperitoneal injection into adult zebrafish. We use a 10 &mu;l NanoFil microsyringe controlled by a Micro4 controller and UltraMicroPump III. This demonstration includes the use of cold water as an anesthetic.

Inyección intraperitoneal en adultos de pez cebra

A convenient method for chemically treating zebrafish is to introduce the reagent into the tank water, where it will be taken up by the fish. However, ...

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 ...

In vivo Electroporation of Morpholinos into the Regenerating Adult Zebrafish Tail Fin

Certain species of urodeles and teleost fish can regenerate their tissues. Zebrafish have become a widely used model to study the spontaneous regeneration of adult tissues, such as the heart1, retina2, spinal cord3, optic nerve4, sensory hair cells5, and fins6.
The zebrafish fin is a relatively simple appendage that is easily manipulated to study multiple stages in epimorphic regeneration. Classically, fin regeneration was characterized by three distinct stages: wound healing, blastema formation, and fin outgrowth. After amputating part of the fin, the surrounding epithelium proliferates and migrates over the wound. At 33 &deg;C, this process occurs within six hours post-amputation (hpa, Figure 1B)6,7. Next, underlying cells from different lineages (ex. bone, blood, glia, fibroblast) re-enter the cell cycle to form a proliferative blastema, while the overlying epidermis continues to proliferate (Figure 1D)8. Outgrowth occurs as cells proximal to the blastema re-differentiate into their respective lineages to form new tissue (Figure 1E)8. Depending on the level of the amputation, full regeneration is completed in a week to a month.
The expression of a large number of gene families, including wnt, hox, fgf, msx, retinoic acid, shh, notch, bmp, and activin-betaA genes, is up-regulated during specific stages of fin regeneration9-16. However, the roles of these genes and their encoded proteins during regeneration have been difficult to assess, unless a specific inhibitor for the protein exists13, a temperature-sensitive mutant exists or a transgenic animal (either overexpressing the wild-type protein or a dominant-negative protein) was generated7,12. We developed a reverse genetic technique to quickly and easily test the function of any gene during fin regeneration.
Morpholino oligonucleotides are widely used to study loss of specific proteins during zebrafish, Xenopus, chick, and mouse development17-19. Morpholinos basepair with a complementary RNA sequence to either block pre-mRNA splicing or mRNA translation. We describe a method to efficiently introduce fluorescein-tagged antisense morpholinos into regenerating zebrafish fins to knockdown expression of the target protein. The morpholino is micro-injected into each blastema of the regenerating zebrafish tail fin and electroporated into the surrounding cells. Fluorescein provides the charge to electroporate the morpholino and to visualize the morpholino in the fin tissue.
This protocol permits conditional protein knockdown to examine the role of specific proteins during regenerative fin outgrowth. In the Discussion, we describe how this approach can be adapted to study the role of specific proteins during wound healing or blastema formation, as well as a potential marker of cell migration during blastema formation.

In vivo Electroporation of Morpholinos into the Regenerating Adult Zebrafish Tail Fin

We describe a method to conditionally knockdown the expression of a target protein during adult zebrafish fin regeneration. This technique involves micro-injecting and electroporating antisense oligonucleotide morpholinos into fin tissue, which allows testing the protein&#x2019;s role in various stages of fin regeneration, including wound healing, blastema formation, and regenerative outgrowth.

En electroporación in vivo de Morpholinos en la regeneración de adultos de pez cebra Aleta de cola

Certain species of urodeles and teleost fish can regenerate their tissues. Zebrafish have become a widely used model to study the spontaneous regeneration ...

Biochemical Titration of Glycogen In vitro

Glycogen is the main energetic polymer of glucose in vertebrate animals and plays a crucial role in whole body metabolism as well as in cellular metabolism. Many methods to detect glycogen already exist but only a few are quantitative. We describe here a method using the Abcam Glycogen assay kit, which is based on specific degradation of glycogen to glucose by glucoamylase. Glucose is then specifically oxidized to a product that reacts with the OxiRed probe to produce fluorescence. Titration is accurate, sensitive and can be achieved on cell extracts or tissue sections. However, in contrast to other techniques, it does not give information about the distribution of glycogen in the cell. As an example of this technique, we describe here the titration of glycogen in two cell lines, Chinese hamster lung fibroblast CCL39 and human colon carcinoma LS174, incubated in normoxia (21% O2) versus hypoxia (1% O2). We hypothesized that hypoxia is a signal that prepares cells to synthesize and store glycogen in order to survive1.

Biochemical Titration of Glycogen In vitro

We describe here an accurate, reproducible and convenient biochemical method for titration of glycogen in vitro. This technique uses the Abcam Glycogen assay kit and is based on successive hydrolysis of glycogen to glucose and glucose titration by fluorescence.

Titulación bioquímica de glucógeno<em&gt; In vitro</em

Glycogen is the main energetic polymer of glucose in vertebrate animals and plays a crucial role in whole body metabolism as well as in cellular ...

Gavaging Adult Zebrafish

The zebrafish has become an important in vivo model in biomedical research. Effective methods must be developed and utilized to deliver compounds or agents in solutions for scientific research. Current methods for administering compounds orally to adult zebrafish are inaccurate due to variability in voluntary consumption by the fish. A gavage procedure was developed to deliver precise quantities of infectious agents to zebrafish for study in biomedical research. Adult zebrafish over 6 months of age were anesthetized with 150 mg/L of buffered MS-222 and gavaged with 5 &mu;l of solution using flexible catheter implantation tubing attached to a cut 22-G needle tip. The flexible tubing was lowered into the oral cavity of the zebrafish until the tip of the tubing extended past the gills (approximately 1 cm). The solution was then injected slowly into the intestinal tract. This method was effective 88% of the time, with fish recovering uneventfully. This procedure is also efficient as one person can gavage 20-30 fish in one hour. This method can be used to precisely administer agents for infectious diseases studies, or studies of other compounds in adult zebrafish.

The increasing use of zebrafish as an animal model requires the development of effective methods for the delivery of known quantities of compounds and solutions. The gavage procedure described below allows for the oral delivery of precise volumes of solution reliably, safely and efficiently to adult zebrafish.

Gavage adultos de pez cebra

The zebrafish has become an important in vivo model in biomedical research. Effective methods must be developed and utilized to deliver compounds or ...

An Assay for Lateral Line Regeneration in Adult Zebrafish

Due to the clinical importance of hearing and balance disorders in man, model organisms such as the zebrafish have been used to study lateral line development and regeneration. The zebrafish is particularly attractive for such studies because of its rapid development time and its high regenerative capacity. To date, zebrafish studies of lateral line regeneration have mainly utilized fish of the embryonic and larval stages because of the lower number of neuromasts at these stages. This has made quantitative analysis of lateral line regeneration/and or development easier in the earlier developmental stages. Because many zebrafish models of neurological and non-neurological diseases are studied in the adult fish and not in the embryo/larvae, we focused on developing a quantitative lateral line regenerative assay in adult zebrafish so that an assay was available that could be applied to current adult zebrafish disease models. Building on previous studies by Van Trump et al.17&#160;that described procedures for ablation of hair cells in adult Mexican blind cave fish and zebrafish (Danio rerio), our assay was designed to allow quantitative comparison between control and experimental groups. This was accomplished by developing a regenerative neuromast standard curve based on the percent of neuromast reappearance over a 24 hr time period following gentamicin-induced necrosis of hair cells in a defined region of the lateral line. The assay was also designed to allow extension of the analysis to the individual hair cell level when a higher level of resolution is required.

Because many zebrafish models of neurological and non-neurological diseases are studied in the adult fish rather than the embryo/larvae, we developed a quantitative lateral line regenerative assay that can be applied to adult zebrafish disease models. The assay involved resolution at the 1) neuromast and 2) individual hair cell levels.

Un ensayo para la línea lateral de regeneración en adultos de pez cebra

Due to the clinical importance of hearing and balance disorders in man, model organisms such as the zebrafish have been used to study lateral line ...

Analysis of Nephron Composition and Function in the Adult Zebrafish Kidney

The zebrafish model has emerged as a relevant system to study kidney development, regeneration and disease. Both the embryonic and adult zebrafish kidneys are composed of functional units known as nephrons, which are highly conserved with other vertebrates, including mammals. Research in zebrafish has recently demonstrated that two distinctive phenomena transpire after adult nephrons incur damage: first, there is robust regeneration within existing nephrons that replaces the destroyed tubule epithelial cells; second, entirely new nephrons are produced from renal progenitors in a process known as neonephrogenesis. In contrast, humans and other mammals seem to have only a limited ability for nephron epithelial regeneration. To date, the mechanisms responsible for these kidney regeneration phenomena remain poorly understood. Since adult zebrafish kidneys undergo both nephron epithelial regeneration and neonephrogenesis, they provide an outstanding experimental paradigm to study these events. Further, there is a wide range of genetic and pharmacological tools available in the zebrafish model that can be used to delineate the cellular and molecular mechanisms that regulate renal regeneration. One essential aspect of such research is the evaluation of nephron structure and function. This protocol describes a set of labeling techniques that can be used to gauge renal composition and test nephron functionality in the adult zebrafish kidney. Thus, these methods are widely applicable to the future phenotypic characterization of adult zebrafish kidney injury paradigms, which include but are not limited to, nephrotoxicant exposure regimes or genetic methods of targeted cell death such as the nitroreductase mediated cell ablation technique. Further, these methods could be used to study genetic perturbations in adult kidney formation and could also be applied to assess renal status during chronic disease modeling.

The zebrafish adult kidney is an excellent system for renal regeneration and disease studies. An essential aspect of such research is the assessment of nephron structure and function. This protocol describes several methodologies that can be implemented to assess nephron tubule composition and to evaluate renal reabsorption.

Análisis de Composición Nephron y función en el riñón adultos de pez cebra

The zebrafish model has emerged as a relevant system to study kidney development, regeneration and disease. Both the embryonic and adult zebrafish kidneys ...