The authors would like to thank Dr. Shaun Coughlin for hosting the filming of this procedure in his laboratory, and for general support. R.A. was supported by the NIH (F32HL110489) and the Sarnoff Cardiovascular Research Foundation. S.R. was supported by a Research Fellowship of the Deutsche Forschungsgemeinschaft (DFG) and the American Heart Association (AHA). D.Y.R.S was supported by the NIH (RO1HL54737), the Packard Foundation, and the Max Planck Society.

NOTA: Certifique-se sempre de que a aprovação IACUC ou comitê de ética está no lugar antes de iniciar qualquer procedimento experimental usando peixe-zebra. 1. Prepare os reagentes e configuração <ol><li> Prepare as seguintes soluções. Encontrar as receitas para todas estas soluções em manuais de peixe-zebra padrão de 10. <ul><li> 500 ml de água ovo </li><li> 200 ml de 0,03% em tricaina ovo Água </li><li> 1x 100 ml de solução salina tamponada com fosfato (PBS) </li><li> Tampão de lise de RBC (opcional) </li><li> Destino tampão de escolha (fixador, Trizol, PBS, etc.) num tubo de microcentrífuga de 1,5 ml em gelo NOTA: fixador e Trizol são tóxicos se entrarem em contacto com a pele. Usar luvas ao manusear estas substâncias. </li></ul></li><li> Prepare configuração dissecção: <ol><li> Posicione a fonte de luz gooseneck sobre o microscópio de dissecação. Colocar a tampa de uma placa de Petri de 9 centímetros na fase de microscópio de dissecação, e verter uma fina camada de fosfato em 1x-lo (a tampa é usada porque o prato em si é muito profunda para a dissecção fácil). </li><li> Coloque a própria placa de Petri (não a tampa) na bancada perto do escopo de dissecação e despeje cerca de 15 ml de PBS 1x nele. Use-o para lavar o coração após a dissecação. Em alternativa, utilizar um tampão de lise de RBC. </li><li> Lâmina de barbear lugar, dois pares de pinças, microtesouras (opcional), e uma pipeta de transferência ao lado do microscópio. Obter um recipiente de gelo, se a eutanásia de um arrefecimento rápido é escolhido. </li><li> Despeje 200 ml de 0,03% tricaina em Egg água em um copo de vidro de 250 ml, se a eutanásia por tricaina é escolhido. Prepare um pequeno saco de risco biológico para eliminação de carcaças de peixe-zebra. </li></ol></li></ol> 2. Prepare Zebrafish <ol><li> Para peixes fixo, trazer peixe fixo, lavadas em PBS, para a configuração do microscópio. <ol><li> Eutanásia todo o peixe-zebra adulto de um arrefecimento rápido com gelo durante&gt; 10 min. </li><li> Use uma pinça para fazer um furo na pele sobre o peritoneu(Longe do coração) para auxiliar a penetração do fixador, e, em seguida, colocá-los em 4% de paraformaldeído em tampão de Fix 10 durante 2 h à TA ou O / N a 4 ° C. </li></ol></li><li> Alternativamente, para o peixe fresco, peixe local para ser sacrificado em um pequeno tanque de retenção e trazer para a configuração do microscópio. Dependendo do protocolo de peixes da instalação individual e os usos a jusante para os corações de peixes dissecados, anestesiar peixe com tricaina ou eutanásia de um arrefecimento rápido antes de decapitação. <ol><li> Para usar o gelo, pegar um peixe com a rede de pesca e coloque em água gelada até que o peixe pára de se mover, cerca de 5 min. </li><li> Como alternativa, para usar tricaina, pegar um peixe com a rede de pesca e coloque no copo da solução até movimentos de emalhar parar. </li></ol></li><li> Rapidamente pegar os peixes mortos por sua barbatana caudal e colocá-lo em seu lado na tampa placa de Petri que foi preenchido com 1x PBS. Use a pinça para levantar uma nadadeira peitoral com uma mão, enquanto estiver usando o razolâmina r para decapitar o peixe com o outro lado, apenas posterior à fixação da barbatana peitoral (Figura 1A). Execute esta etapa ou olhando através do microscópio ou apenas visualizar diretamente os peixes no palco microscópio. NOTA: Peixes recentemente sacrificados ainda vai sangrar após a decapitação. </li></ol><img alt="Figura 1" src="/files/ftp_upload/52248/52248fig1highres.jpg" /> Figura 1. Zebrafish dissecção coração adulto utiliza marcos anatômicos de peixe-zebra. (A) para decapitar o peixe, levante a nadadeira peitoral com uma pinça e usar uma lâmina limpa afiada ao longo da linha pontilhada vermelha, como mostrado. (B) Para firmar a cabeça de peixe, coloque um dente do fórceps na boca dos peixes enquanto o outro tine fica do outro lado do olho, e, em seguida, virar a cabeça de peixe de modo que a superfície ventral é para cima e as duas pontas da pinça são estáveis ​​contra a parte inferior da placa de Petri. (C) Use a forc livreeps para cortar a ligação do opérculo (seta). (D) elevação isso, a aorta dorsal é visível como uma estrutura branca com uma listra rosa denotando sangue luminal (seta). <a href="https://www.jove.com/files/ftp_upload/52248/52248fig1large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta figura.</a> 3. Dissecar o Coração <ol><li> Visualize a cabeça de peixe sob o microscópio. Com uma pinça, estabilizar a cabeça de peixe, colocando um dente da pinça na boca de peixe, através do cérebro, enquanto que o outro dente é fora da cabeça, através do olho (Figura 1B). Certifique-se de ambas as garras de pinça são estáveis ​​contra o fundo do prato de petri. Segurando a cabeça de peixe desta forma, a sua superfície ventral deve estar voltado para cima. </li><li> Com a outra mão, utilizar a segunda pinça para cortar a ligação ventral do opérculo ao corpo (seta, Figura 1C). Levantar esta ligeiramente com a pinça, o dØrsal aorta aparece por baixo como uma estrutura branca com uma listra vermelha de sangue na luz aórtica (seta, Figura 1D). Corte as aorta dorsal, com a pinça por beliscar a aorta e puxando para cima; em alternativa, usar microtesouras para cortar a aorta dorsal. </li><li> Agora, use a segunda pinça para agarrar a barbatana peitoral de sua base, incluindo a cartilagem corpo, na base da nadadeira, e levante esta off. Repita com a outra barbatana peitoral. Ocasionalmente, o coração sai com as nadadeiras peitorais, então examinar estas peças para certificar-se o coração não está conectado antes de descartá-los. NOTA: Neste ponto, o coração deve estar visível, ainda intacto e conectado à cabeça de peixe restante (embora ocasionalmente ele sai com as nadadeiras peitorais). O coração pode ser identificado pela sua forma, a sua cor-de-rosa, e os seus estar rodeado por pericárdio pigmentada. Porque a eutanásia dos peixes é realizada rapidamente, corações peixe acabado de eutanásia pode ainda estar batendo slowly. </li><li> Deixe de lado a cabeça de peixe com os primeiros fórceps, para que ambas as mãos segurando uma pinça e são gratuitas. Use as duas pinças de provocar o coração longe do pericárdio. Agarrar o coração pelo restante da aorta dorsal, enquanto o restante pericárdio é puxado para fora. NOTA: Se fixa ou fresco, o coração é robusto a suave puxando enquanto o tecido conjuntivo circundante é mais friável. Portanto, qualquer tecido de pericárdio circundante pode ser dissecado com o coração restante intacto. </li><li> Descarte a carcaça de peixe sobra no saco de risco biológico. </li></ol> 4. Prepare o coração para aplicações a jusante <ol><li> Utilizando uma pinça, segure o coração pela borda da aorta dorsal / arterial bulbus e colocar o coração no prato fresco de 1x PBS. Em alternativa, utilizar uma pipeta de transferência. Mova o coração e para trás na PBS cerca de 10x para lavar o máximo de sangue possível. </li><li> Para aplicações em que é importante para remover todos possibiliOs glóbulos le, lavar em uma placa de Petri de 9 centímetros, com 15 ml de tampão de lise de RBC em vez de PBS, usando o mesmo movimento de vai-e-vem. Se preservar a estrutura do coração não é importante para a aplicação a jusante (por exemplo, tornando o RNA), usar os fórceps ou microtesouras para abrir a cavidade do coração e facilitar enxaguando de células sanguíneas. </li><li> Para aplicações em que são desejados diferentes câmaras cardíacas, utilize uma pinça ou microtesouras para dissecar o bulbo arterial, átrio, e ventrículo afastados uns dos outros. </li><li> Transferir o coração, ou câmaras separadas, para o buffer de destino em gelo. NOTA: destinos comuns incluem buffers para dissociação celular, paraformaldeído 4%, ou Trizol. </li></ol>

<ol>
	<li>Arnaout, R., 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=Zebrafish+model+for+human+long+QT+syndrome.">Zebrafish model for human long QT syndrome.</a> Proceedings of the National Academy of Sciences of the United States of America. 104 (27), 11316-11321 (2007).</li><li>Chi, N. 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=Genetic+and+physiologic+dissection+of+the+vertebrate+cardiac+conduction+system.">Genetic and physiologic dissection of the vertebrate cardiac conduction system.</a> PLoS Biology. 6 (5), 109 (2008).</li><li>Poss, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Getting+to+the+heart+of+regeneration+in+zebrafish.">Getting to the heart of regeneration in zebrafish.</a> Seminars in Cell &amp; Developmental Biology. 18 (1), 36-45 (2007).</li><li>Fang, Y., 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=Translational+profiling+of+cardiomyocytes+identifies+an+early+Jak1/Stat3+injury+response+required+for+zebrafish+heart+regeneration.">Translational profiling of cardiomyocytes identifies an early Jak1/Stat3 injury response required for zebrafish heart regeneration.</a> Proceedings of the National Academy of Sciences of the United States of America. 110 (33), 13416-13421 (2013).</li><li>Manoli, M., Driever, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence-activated+cell+sorting+(FACS)+of+fluorescently+tagged+cells+from+zebrafish+larvae+for+RNA+isolation.">Fluorescence-activated cell sorting (FACS) of fluorescently tagged cells from zebrafish larvae for RNA isolation.</a> Cold Spring Harbor Protocols. 2012 (8), (2012).</li><li>Cannon, J. E., 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=Global+analysis+of+the+haematopoietic+and+endothelial+transcriptome+during+zebrafish+development.">Global analysis of the haematopoietic and endothelial transcriptome during zebrafish development.</a> Mechanisms of Development. 130 (2-3), 122-131 (2013).</li><li>Wang, Z., Gerstein, M., Snyder, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA-Seq:+a+revolutionary+tool+for+transcriptomics.">RNA-Seq: a revolutionary tool for transcriptomics.</a> Nature Reviews Genetics. 10 (1), 57-63 (2009).</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> Journal of Visualized Experiments. 37, (2010).</li><li>Singleman, C., Holtzman, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+dissection+in+larval,+juvenile+and+adult+zebrafish,+Danio+rerio.">Heart dissection in larval, juvenile and adult zebrafish, Danio rerio.</a> Journal of Visualized Experiments. 55, (2011).</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=.">.</a> The zebrafish book: a guide for the laboratory use of zebrafish (Brachydanio rerio. , (1993).</li></ol>

The authors have no disclosures.

Embora os métodos para dissecar o coração de adulto peixe-zebra foram descritos, estes métodos foram demorada e normalmente causado dano ao coração durante a dissecção. Para realizar experiências onde pode ser necessário um grande número de coração do adulto, e / ou ao evitar a degradação do tecido do coração é importante para aplicações a jusante, o tempo necessário utilizando técnicas tradicionais de dissecção é proibitivo. Da mesma forma, a obtenção de reprodutível, corações intactos nã...

Zebrafish are an excellent model for studying heart development and human disease1,2. Specific advantages include the translucent nature of zebrafish embryos, the availability of many genetic mutants and transgenic reporter lines, and the availability of genome editing technologies. In addition to their advantages for studying early heart development, zebrafish are an ideal system for studying vertebrate heart regeneration3.
More recently, adult zebrafish are playing an important part in bioinformatics approaches to studying cardiovascular development and disease, due to their relatively large clutch size and relatively quick and inexpensive breeding compared to other vertebrate models. Promising techniques include ribosome profiling, RNA-Seq, and cell dissociation and FACS sorting4-7. However, for these techniques the quality of the data can depend on obtaining a large number of samples in a rapid, efficient, and reproducible manner, before gene regulatory, metabolic, transcriptional, and other changes occur.
Dissection of adult zebrafish organs has been described in the past8,9. However, previous approaches to dissection of the heart were slow, ran the risk of damaging the heart during dissection, required special tools, and/or required fixation of the zebrafish prior to dissection; for these reasons, past approaches to zebrafish adult heart dissection were not optimized for high-throughput applications and/or applications requiring fresh tissue.
Here, we describe a method for adult zebrafish heart dissection that is simple, fast, efficient, and reproducible, while preserving cardiac morphology. This method does not include cutting into the pericardial space and therefore does not risk damaging the heart during dissection. Instead, this method relies on anatomical landmarks of the zebrafish, and therefore, it is highly reproducible. This dissection method is also versatile in that it can be used on fresh or fixed fish, and on zebrafish as young as one month old. Finally, this method results in minimal suffering to the zebrafish because after anesthesia and/or rapid cooling, the fish is additionally decapitated and pithed in the course of the dissection procedure.

<table border="0" cellpadding="0" cellspacing="0" >
	<tbody>
		<tr >
			<td >small tank for transporting fish</td>
			<td >Aquaneering</td>
			<td >ZHCT100</td>
			<td></td>
		</tr>
		<tr >
			<td >fish net</td>
			<td >Petsmart</td>
			<td >36-16731</td>
			<td></td>
		</tr>
		<tr >
			<td >250mL glass beaker</td>
			<td >Kimble</td>
			<td >14005-250</td>
			<td></td>
		</tr>
		<tr >
			<td >9cm polystyrene petri dish</td>
			<td >Nunc</td>
			<td >172958</td>
			<td></td>
		</tr>
		<tr >
			<td >razor blade</td>
			<td >Personna American Safety Razor Company</td>
			<td >94-120-71</td>
			<td></td>
		</tr>
		<tr >
			<td >two Dumont #5SF forceps</td>
			<td >Fine Science Tools</td>
			<td >11252-00</td>
			<td></td>
		</tr>
		<tr >
			<td >dissecting microscope</td>
			<td >Olympus</td>
			<td >SZX16</td>
			<td></td>
		</tr>
		<tr >
			<td >Tricaine</td>
			<td >Sigma</td>
			<td >A-5040</td>
			<td></td>
		</tr>
		<tr >
			<td >plastic transfer pipette</td>
			<td >Thermo Scientific</td>
			<td >202-20S</td>
			<td></td>
		</tr>
		<tr >
			<td >gooseneck light source</td>
			<td >Dolan-Jenner Industries, Inc</td>
			<td >Fiber-Lite 180 Illuminator, 181 Dual Gooseneck System</td>
			<td></td>
		</tr>
		<tr >
			<td >fluorescent light source</td>
			<td >Lumen Dynamics</td>
			<td >X-Cite 120Q</td>
			<td>optional</td>
		</tr>
		<tr >
			<td >micro-scissors</td>
			<td >Biomedical Research Instruments, Inc</td>
			<td >11-1000</td>
			<td>optional</td>
		</tr>
		<tr >
			<td >RBC Lysis Buffer</td>
			<td >eBioscience</td>
			<td >00-4333-57</td>
			<td>optional</td>
		</tr>
	</tbody>
</table>

recovery of adult zebrafish hearts for high-throughput applications

A utilização do sistema modelo para estudar o desenvolvimento do peixe-zebra, a regeneração, e a doença está a expandir para utilização de coração do adulto para dissociação de células e purificação de RNA, DNA e proteínas. Todas estas aplicações exigem a rápida recuperação de um número significativo de corações de peixe-zebra para evitar gene regulador, metabólicas e outras mudanças que começam após a morte. Corações de peixe-zebra adultos são também necessários para estudar a estrutura do coração para uma variedade de mutantes e para estudar a regeneração cardíaca. No entanto, a dissecção do coração do peixe-zebra tradicional é lento e difícil e requer ferramentas especializadas, tornando dissecção em larga escala de corações de peixe-zebra adultos tedioso. Os métodos tradicionais também abrigam o risco de danificar o coração durante a dissecção. Aqui, descrevemos um método para dissecção de corações peixe-zebra adulto que é rápido, reprodutível, e preserva a arquitetura coração. Além disso, este método não requer ferramentas especializadas, é indolor para o peixe-zebra,pode ser realizada em amostras frescas ou fixos, e pode ser realizado em peixes-zebra tão jovens como um mês de idade. A abordagem descrita amplia o uso de peixe-zebra adulto para a investigação cardiovascular.

Usando este método, um peixe-zebra coração adulto pode ser dissecado em menos de 1 minuto, em comparação com mais de 5 min, utilizando métodos tradicionais 8. Corações dissecados utilizando este método são seguramente intacta (Figura 2A), enquanto que os métodos tradicionais requerem 8 cortar cegamente no pericárdio e, portanto, comumente causar dano ou perda do átrio ou bulbus arterial (Figura 2B). Corações dissecados manter a sua integridade estrut...

Watch this Scientific Journal Video about Recovery of Adult Zebrafish Hearts for High-throughput Applications at JoVE.com

Recovery of Adult Zebrafish Hearts for High-throughput Applications

Use of zebrafish for cardiovascular research is expanding towards research on adult hearts. For these applications, quick and simple isolation of cardiac tissues is key to avoid post-mortem changes and to obtain an adequate number of samples. Here, we describe a fast and reproducible method for dissecting adult zebrafish hearts.

Recuperação de Zebrafish Adulto Corações para aplicações de alto rendimento

Use of the zebrafish model system for studying development, regeneration, and disease is expanding toward use of adult hearts for cell dissociation and ...

recovery-of-adult-zebrafish-hearts-for-high-throughput-applications

Research

JoVE Journal

Biology

12.2K visualizações.  University of California San Francisco. Use of zebrafish for cardiovascular research is expanding towards research on adult hearts. For these applications, quick and simple isolation of cardiac tissues is key to avoid post-mortem changes and to obtain an adequate number of samples. Here, we describe a fast and reproducible method for dissecting adult zebrafish hearts.

Vídeo: Recovery of Adult Zebrafish Hearts for High-throughput Applications

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to the original protocol that both streamline the procedure and increase sample uniformity.  First, we normalize all sperm volumes using freezing media that does not contain the cryoprotectant. Second, cryopreserved sperm are stored in cryovials instead of capillary tubes.  The rates of sperm freezing and thawing (&delta;&deg;C/time) are probably the two most critical variables to control in this procedure.  For this reason, do not substitute different tubes for those specified.  Working in teams of 2 it is possible to freeze the sperm of 100 males per team in ~2 hrs.  Sperm cryopreserved using this protocol has an average of 25% fertility (measured as the number of viable embryos generated in an in vitro fertilization divided by the total number of eggs fertilized) and this percent fertility is stable over many years.

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a high-throughput sperm cryopreservation protocol for zebrafish. Sperm cryopreserved using this protocol has an average of 25% fertility in subsequent vitro fertilization and is stable over many years.

Um método de alta taxa de transferência para Zebrafish criopreservação de espermatozóides e In Vitro Fertilização

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to ...

Biologia

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.

Injeção intraperitoneal em Zebrafish Adulto

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, ...

Transplantation of Cells Directly into the Kidney of Adult Zebrafish

Regenerative medicine based on the transplantation of stem or progenitor cells into damaged tissues has the potential to treat a wide range of chronic diseases1. However, most organs are not easily accessible, necessitating the need to develop surgical methods to gain access to these structures. In this video article, we describe a method for transplanting cells directly into the kidney of adult zebrafish, a popular model to study regeneration and disease2. Recipient fish are pre-conditioned by irradiation to suppress the immune rejection of the injected cells3. We demonstrate how the head kidney can be exposed by a lateral incision in the flank of the fish, followed by the injection of cells directly in to the organ. Using fluorescently labeled whole kidney marrow cells comprising a mixed population of renal and hematopoietic precursors, we show that nephron progenitors can engraft and differentiate into new renal tissue - the gold standard of any cell-based regenerative therapy. This technique can be adapted to deliver purified stem or progenitor cells and/or small molecules to the kidney as well as other internal organs and further enhances the zebrafish as a versatile model to study regenerative medicine.

Cell transplantation is an essential technique for studying tissue regeneration and for developing cell-based therapies of disease. We demonstrate here a microsurgical technique that permits the transplantation of genetically labeled cells directly into the kidney of adult zebrafish fish.

Transplante de células diretamente no Rim de Adulto Zebrafish

Regenerative medicine based on the transplantation of stem or progenitor cells into damaged tissues has the potential to treat a wide range of chronic ...

High-throughput Saccharification Assay for Lignocellulosic Materials

Polysaccharides that make up plant lignocellulosic biomass can be broken down to produce a range of sugars that subsequently can be 
used in establishing a biorefinery. These raw materials would constitute a new industrial platform, which is both sustainable and carbon neutral, to replace 
the current dependency on fossil fuel. The recalcitrance to deconstruction observed in lignocellulosic materials is produced by several intrinsic properties 
of plant cell walls. Crystalline cellulose is embedded in matrix polysaccharides such as xylans and arabinoxylans, and the whole structure is encased by the 
phenolic polymer lignin, that is also difficult to digest 1. In order to improve the digestibility of plant materials we need to discover the main bottlenecks 
for the saccharification of cell walls and also screen mutant and breeding populations to evaluate the variability in saccharification 2. These tasks require 
a high throughput approach and here we present an analytical platform that can perform saccharification analysis in a 96-well plate format. This platform has 
been developed to allow the screening of lignocellulose digestibility of large populations from varied plant species. We have scaled down the reaction volumes 
for gentle pretreatment, partial enzymatic hydrolysis and sugar determination, to allow large numbers to be assessed rapidly in an automated system.
This automated platform works with milligram amounts of biomass, performing ball milling under controlled conditions to reduce the plant 
materials to a standardised particle size in a reproducible manner. Once the samples are ground, the automated formatting robot dispenses specified and recorded 
amounts of material into the corresponding wells of 96 deep well plate (Figure 1). Normally, we dispense the same material into 4 wells to have 4 replicates for 
analysis. Once the plates are filled with the plant material in the desired layout, they are manually moved to a liquid handling station (Figure 2). In this 
station the samples are subjected to a mild pretreatment with either dilute acid or alkaline and incubated at temperatures of up to 90&deg;C. The pretreatment solution 
is subsequently removed and the samples are rinsed with buffer to return them to a suitable pH for hydrolysis. The samples are then incubated with an enzyme
mixture for a variable length of time at 50&deg;C. An aliquot is taken from the hydrolyzate and the reducing sugars are automatically determined by the MBTH 
colorimetric method.

A simple, rapid method for determining the saccharification potential of large numbers of plant biomass samples is described. The automated platform for this analysis involves the preparation of the plant biomass for analysis in 96 well plates and the subsequent performance of pretreatment, hydrolysis and quantification of the sugars released.

Alto rendimento Assay Sacarificação para materiais lignocelulósicos

Polysaccharides that make up plant lignocellulosic biomass can be broken down to produce a range of sugars that subsequently can be 
used in establishing ...

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.

Em Eletroporação vivo de Morpholinos na Retina Zebrafish Adulto

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.

Na eletroporação in vivo de Morpholinos no Adulto Regeneração Zebrafish Cauda Fin

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

Blood Collection for Biochemical Analysis in Adult Zebrafish

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 molecular events and therapeutic strategies as well as for evaluating the physiological mechanisms of some pathologies1. 
There are relatively few publications related to adult zebrafish physiology of organs and systems2, which may lead researchers to infer that the basic techniques needed to allow the exploration of zebrafish systems are lacking3. Hematologic biochemical values of zebrafish were first reported in 2003 by Murtha and colleagues4 who employed a blood collection technique first described by Jagadeeswaran and colleagues in 1999. Briefly, blood was collected via a micropipette tip through a lateral incision, approximately 0.3 cm in length, in the region of the dorsal aorta5. Because of the minute dimensions involved, this is a high-precision technique requiring a highly skilled practitioner. The same technique was used by the same group in another publication in that same year6. In 2010, Eames and colleagues assessed whole blood glucose levels in zebrafish7. They gained access to the blood by performing decapitations with scissors and then inserting a heparinized microcapillary collection tube into the pectoral articulation. They mention difficulties with hemolysis that were solved with an appropriate storage temperature based on the work Kilpatrick et al.8. When attempting to use Jagadeeswaran's technique in our laboratory, we found that it was difficult to make the incision in precisely the right place as not to allow a significant amount of blood to be lost before collection could be started. 
Recently, Gupta et al.9 described how to dissect adult zebrafish organs, Kinkle et al.10 described how to perform intraperitoneal injections, and Pugach et al.11 described how to perform retro-orbital injections. However, more work is needed to more fully explore basic techniques for research in zebrafish.
The small size of zebrafish presents challenges for researchers using it as an experimental model. Furthermore, given this smallness of scale, it is important that simple techniques are developed to enable researchers to explore the advantages of the zebrafish model.

This paper presents a technique for collection of blood from the dorsal aorta of Zebrafish. It also provides instructions for obtaining serum for use in biochemical analyses, such as tests for determining cholesterol and triglyceride levels.

Coleta de sangue para análise bioquímica em Zebrafish Adulto

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 ...

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.

Gavaging Zebrafish Adulto

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

A Manual Small Molecule Screen Approaching High-throughput Using Zebrafish Embryos

Zebrafish have become a widely used model organism to investigate the mechanisms that underlie developmental biology and to study human disease pathology due to their considerable degree of genetic conservation with humans. Chemical genetics entails testing the effect that small molecules have on a biological process and is becoming a popular translational research method to identify therapeutic compounds. Zebrafish are specifically appealing to use for chemical genetics because of their ability to produce large clutches of transparent embryos, which are externally fertilized. Furthermore, zebrafish embryos can be easily drug treated by the simple addition of a compound to the embryo media. Using whole-mount in situ hybridization (WISH), mRNA expression can be clearly visualized within zebrafish embryos. Together, using chemical genetics and WISH, the zebrafish becomes a potent whole organism context in which to determine the cellular and physiological effects of small molecules. Innovative advances have been made in technologies that utilize machine-based screening procedures, however for many labs such options are not accessible or remain cost-prohibitive. The protocol described here explains how to execute a manual high-throughput chemical genetic screen that requires basic resources and can be accomplished by a single individual or small team in an efficient period of time. Thus, this protocol provides a feasible strategy that can be implemented by research groups to perform chemical genetics in zebrafish, which can be useful for gaining fundamental insights into developmental processes, disease mechanisms, and to identify novel compounds and signaling pathways that have medically relevant applications.

The zebrafish is an excellent experimental organism to study vertebrate developmental processes and model human disease. Here, we describe a protocol on how to perform a manual high-throughput chemical screen in zebrafish embryos with a whole-mount in situ hybridization (WISH) read-out.

Um manual de tela pequena molécula Aproximando de alta capacidade Usando embriões Zebrafish

Zebrafish have become a widely used model organism to investigate the mechanisms that underlie developmental biology and to study human disease pathology ...

High-throughput Screening for Chemical Modulators of Post-transcriptionally Regulated Genes

Both transcriptional and post-transcriptional regulation have a profound impact on genes expression. However, commonly adopted cell-based screening assays focus on transcriptional regulation, being essentially aimed at the identification of promoter-targeting molecules. As a result, post-transcriptional mechanisms are largely uncovered by gene expression targeted drug development. Here we describe a cell-based assay aimed at investigating the role of the 3&#39; untranslated region (3&#8217; UTR) in the modulation of the fate of its mRNA, and at identifying compounds able to modify it. The assay is based on the use of a luciferase reporter construct containing the 3&#8217; UTR of a gene of interest stably integrated into a disease-relevant cell line. The protocol is divided into two parts, with the initial focus on the primary screening aimed at the identification of molecules affecting luciferase activity after 24 hr of treatment. The second part of the protocol describes the counter-screening necessary to discriminate compounds modulating luciferase activity specifically through the 3&#8217; UTR. In addition to the detailed protocol and representative results, we provide important considerations about the assay development and the validation of the hit(s) on the endogenous target. The described cell-based reporter gene assay will allow scientists to identify molecules modulating protein levels via post-transcriptional mechanisms dependent on a 3&#8217; UTR.

Here we describe a cell-based reporter gene assay as a valuable tool to screen chemical libraries for compounds modulating post-transcriptional control mechanisms exerted through 3&#8217; UTR.

Rastreio de alto rendimento para moduladores químicos de Genes Post-transcriptionally Regulamentados

Both transcriptional and post-transcriptional regulation have a profound impact on genes expression. However, commonly adopted cell-based screening assays ...