Gostaríamos de agradecer aos membros do Laboratório de Barresi pelo seu apoio e comentários úteis sobre este manuscrito. Agradecemos a Alexander Workman por sua assistência técnica constante, bem como a equipe de cuidados de animais por sua ajuda na manutenção do Smith College colônia Zebrafish. Agradecemos também a Mike Hallacy, Rudi Rottenfusser, e Carl Zeiss microfilmagem para emprestar algum equipamento de microscopia para o filmin deste protocolo. Este trabalho foi apoiado por uma pesquisa financiada NSF concessão, 0.615.594.

<ol>
	<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+guide+for+the+laboratory+use+of+zebrafish+(Danio.">A guide for the laboratory use of zebrafish (Danio.</a> The Zebrafish Book. , (2007).</li><li>N&#252;sslein-Volhard, C., Dahm, R. e. d. <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+Practical+Approach.">Zebrafish A Practical Approach.</a> , (2002).</li><li>Graeden, E., Sive, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+imaging+of+the+zebrafish+embryonic+brain+by+confocal+microscopy.">Live imaging of the zebrafish embryonic brain by confocal microscopy.</a> J Vis Exp. (26), (2009).</li><li>Gilmour, D. T., Jessen, J. R., Lin, S., N&#252;sslein-Volhard, C., Dahm, R. e. d. <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+practical+approach.">Zebrafish, a practical approach.</a> 1, 121-121 (2002).</li><li>Woo, K., Shih, J., Fraser, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fate+maps+of+the+zebrafish+embryo.">Fate maps of the zebrafish embryo.</a> Curr Opin Genet Dev. 5 (4), 439-439 (1995).</li><li>Barresi, M. J., Hutson, L. D., Chien, C. B., Karlstrom, R. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hedgehog+regulated+Slit+expression+determines+commissure+and+glial+cell+position+in+the+zebrafish+forebrain.">Hedgehog regulated Slit expression determines commissure and glial cell position in the zebrafish forebrain.</a> Development. 132 (16), 3643-3643 (2005).</li><li>Kozlowski, D. J., Murakami, T., Ho, R. K., Weinberg, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+cell+movement+and+tissue+patterning+in+the+zebrafish+embryo+revealed+by+fate+mapping+with+caged+fluorescein.">Regional cell movement and tissue patterning in the zebrafish embryo revealed by fate mapping with caged fluorescein.</a> Biochem Cell Biol. 75 (5), 551-551 (1997).</li><li>Halloran, M. C., Murakami, T., Ho, R. K., Weinberg, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-induced+gene+expression+in+specific+cells+of+transgenic+zebrafish.">Laser-induced gene expression in specific cells of transgenic zebrafish.</a> Development. 127 (9), 1953-1953 (2000).</li><li>Hardy, M. E., Ross, L. V., Chien, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focal+gene+misexpression+in+zebrafish+embryos+induced+by+local+heat+shock+using+a+modified+soldering+iron.">Focal gene misexpression in zebrafish embryos induced by local heat shock using a modified soldering iron.</a> Dev Dyn. 236 (11), 3071-3071 (2007).</li></ol>

The authors have nothing to disclose.

A criação de embriões quiméricos é uma ferramenta poderosa que aborda questões de pesquisa dentro de muitos sistemas modelo diversos, ou seja, voar a fruta (Drosophila melanogaster), worm (C.elegans), peixe-zebra (D.rerio) e mouse (M.musculus). Argumentamos que o sistema modelo peixe-zebra é particularmente adequada para a geração de quimeras de uma maneira relativamente fácil, rápido e versátil. O peixe-zebra é um vertebrado que se desenvolve fora da mãe tornando-o significativamente mais acessível em comparação com o modelo de mouse. Peixe-zebra também são significativamente maiores do que moscas ou minhocas, o que simplifica manipulações embrionárias, como o transplante de células. Além disso, a capacidade de combinar procedimentos transplante de células com técnicas transgênicas permite uma grande variedade de experiências possíveis em que a função do gene pode ser manipulado em um tecido localizado forma específica. Por exemplo, clones pequeno de GFP + ou Rodamina células marcadas permitem a caracterização da morfologia celular completo que muitas vezes são perdidos em um doador homozigoto transgênicos ou são impossíveis de visualizar devido à rotulagem diferencial subcelulares com anticorpos comum. Além disso, usando células transgenicamente tagged ou fluorescente cheia, podemos rastrear células do doador no embrião do zebrafish vivem ao longo do tempo. Timelapse imagem de células individuais fornece uma análise da novela de comportamento celular no contexto de todo o organismo. Nosso laboratório também combina o uso de choque térmico induzível linhagens transgênicas com transplantes de células tal que certos sinais de orientação axônio pode ser misexpressed em células do doador após a elevação da temperatura de incubação (dados não mostram). Esta técnica é uma abordagem extremamente poderoso e directo a nível local misexpress uma proteína de interesse de uma forma espacial e temporal específico, o que nos permite ver como a proteína específica afeta o desenvolvimento. No nosso caso, esta técnica pode ampliar nosso conhecimento por trás da função de pistas Slit-Robo orientação no posicionamento das comissuras e células gliais na 5 linha média. Outras abordagens para genes localmente misexpressing como uncaging UV focal e ferramentas heatshock localizadas (laser ou ferro de solda), não oferecem caminhos alternativos para manipular a expressão de genes e marcadores em um pequeno aglomerado de células 7-9, no entanto, estabelece um transplante de células ambiente final de análise que está livre de qualquer trauma induzido por laser UV, calor ou fazer o transplante de células uma abordagem mais experimental controlado. Em conclusão, nós encontramos procedimentos transplante de células a ser uma parte crucial da nossa investigação em biologia do desenvolvimento neurológico. Geração de clones de células com propriedades diferentes é uma ferramenta crítica para o biólogo de desenvolvimento para enfrentar questões fundamentais de comportamentos de células, a função do gene, e autonomia da célula.

<table border="1" cellspacing="0" cellpadding="0"><tbody><tr><td> Nome </td><td> Tipo </td><td> Companhia </td><td> Número de catálogo </td><td> Especificidades </td></tr><tr><td> Placas de Petri </td><td> Ferramenta </td><td> Fisherbrand </td><td> 08-757-13 </td><td> 100 x 15 mm </td></tr><tr><td> Placas de cultura de fundo de vidro </td><td> Ferramenta </td><td> Mattek </td><td> P35G-1.5-2.0-C </td><td> 35 x 15mm, n º 1.5, não revestidos, Gama-irradiados </td></tr><tr><td> Largura Diâmetro Vidro pipetas Pasteur </td><td> Ferramenta </td><td> Fisherbrand </td><td> 63A-53-WT </td><td></td></tr><tr><td> De vidro de filamentos capilares para moldes vale (sem filamento) e agulhas de injeção (com filamento) </td><td> Ferramenta </td><td> Precision Instruments mundo </td><td> 1B150F-4 </td><td> 4 polegadas (100 mm), 1,5 / 0,84 OD / ID (mm) </td></tr><tr><td> Transplante de Capilares (TransferTip) </td><td> Ferramenta </td><td> Eppendorf </td><td> 83000122-8 </td><td> Tipo IV, Int, estéril. 15μm, 20 bend grau </td></tr><tr><td> Molde transplante </td><td> Ferramenta </td><td> Ferramentas Adaptive Ciência </td><td> PT-1 </td><td> 150 divots triangular para segurar os embriões individuais </td></tr><tr><td> Agarose, Tipo I </td><td> Reagente </td><td> Sigma Aldrich </td><td> A6013-250G </td><td> Agarose 1,5% feita em EM </td></tr><tr><td> (Antibiótico) Medium Embrião </td><td> Reagente </td><td></td><td></td><td> Ver Westerfield, 2007 </td></tr><tr><td> Tampão de fosfato </td><td> Reagente </td><td></td><td></td><td> Ver Westerfield, 2007 </td></tr><tr><td> Pinça Watchman </td><td> Ferramenta </td><td> Multa Ferramentas Ciência </td><td></td><td> 100 + milímetros ponta (sem graça), a ponta 50 milímetros </td></tr><tr><td> Rodamina B Dextran </td><td> Lineage traçador corante </td><td> Sondas moleculares, Invitrogen </td><td> D1824 </td><td> 10.000 MW Da, lisina-fixável, corante (590nm) vermelho fluorescente animado com luz verde (570nm) </td></tr><tr><td> Microscópio de dissecação </td><td> Microscópio </td><td> Olimpo </td><td> SZX7 </td><td></td></tr><tr><td> Microscópio fluorescente Stereo </td><td> Microscópio </td><td> Zeiss </td><td> Lumar </td><td> Totalmente Automatizado Joystick Controlada (Sycop) </td></tr><tr><td> Aparelho de transplante </td><td> Ferramenta </td><td> Eppendorf Corp </td><td> Airtram </td><td></td></tr><tr><td> Micromanipulador automatizado </td><td> Ferramenta </td><td> Eppendorf Corp </td><td> TransferMan NK2 </td><td> Joystick controlado </td></tr><tr><td> Micromanipulador </td><td> Ferramenta </td><td> Applied Scientific Instruments, Inc. </td><td> 00-42-101-0000 </td><td> MM33 Direita </td></tr><tr><td> Microinjetor com a Unidade de Pressão Voltar </td><td> Ferramenta </td><td> Applied Scientific Instruments, Inc. </td><td> MPPI-2 BPU </td><td></td></tr><tr><td> Flamming / Brown micropipeta Puller </td><td> Ferramenta </td><td> Sutter Instrument Company </td><td> Modelo P97 </td><td> Programa: Heat 550; Velocidade de 200; Time / Delay 200; Impulsão 120. </td></tr></tbody></table>

tissue targeted embryonic chimeras: zebrafish gastrula cell transplantation

Algumas questões fundamentais no campo da biologia do desenvolvimento só pode ser respondida quando as células são colocadas em ambientes novos ou quando pequenos grupos de células em um contexto maior são alterados. Observando como uma célula interage e se comporta em um ambiente único, é essencial para caracterizar funções celulares. Determinar como o misexpression localizada de uma proteína específica influências que envolve as células fornece informações detalhadas sobre os papéis que a proteína desempenha em uma variedade de processos de desenvolvimento. Nosso laboratório utiliza o sistema de modelo de zebrafish exclusivamente para combinar abordagens genéticas com técnicas de transplante clássico para gerar quimeras genotípica ou fenotípica. Estudamos as interações neurônio-glia durante a formação do prosencéfalo comissuras no zebrafish. Este vídeo descreve um método que permite que o nosso laboratório para investigar o papel das populações astroglial no diencéfalo e os papéis de pistas de orientação específicas que influenciam os axônios projetar como eles cruzam a linha média. Devido à sua embriões zebrafish transparência são modelos ideais para este tipo de colocação de células ectópica ou misexpression gene localizado. Rastreamento de células transplantadas pode ser realizada utilizando um corante vital ou uma linha de peixes transgênicos expressando uma proteína fluorescente. Demonstramos aqui como preparar embriões de doadores com um traçador corante vital para o transplante, bem como a forma de extrair e transplante de células de um embrião gástrula encenado para outro. Apresentamos dados mostrando GFP ectópica + células transgênicas dentro do cérebro anterior de embriões zebrafish e caracterizar a localização destas células em relação ao prosencéfalo comissuras. Além disso, show de laser microscopia confocal de timelapse Alexa 594 células marcadas transplantado em um GFP + embrião hospedeiro transgênico. Estes dados fornecem evidências de que gástrula transplante encenado permite o posicionamento alvo de células ectópicas para tratar uma variedade de questões em Biologia do Desenvolvimento.

Watch this Scientific Journal Video about Tissue Targeted Embryonic Chimeras: Zebrafish Gastrula Cell Transplantation at JoVE.com

Tissue Targeted Embryonic Chimeras: Zebrafish Gastrula Cell Transplantation

Zebrafish transplante de células permite a combinação de genética e da embriologia para gerar quimeras tecidos específicos. Este vídeo demonstra gástrula encenado transplantes de células que têm permitido o nosso laboratório para investigar o papel das populações astroglial e pistas de orientação específica durante a formação da comissura no prosencéfalo.

Tecido alvo quimeras embrionárias: Zebrafish celular Gástrula Transplante

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

tissue-targeted-embryonic-chimeras-zebrafish-gastrula-cell

Research

JoVE Journal

Biology

19.2K visualizações.  Smith College. Zebrafish transplante de células permite a combinação de genética e da embriologia para gerar quimeras tecidos específicos. Este vídeo demonstra gástrula encenado transplantes de células que têm permitido o nosso laboratório para investigar o papel das populações astroglial e pistas de orientação específica durante a formação da comissura no prosencéfalo.

Vídeo: Tissue Targeted Embryonic Chimeras: Zebrafish Gastrula Cell Transplantation

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.

Transplante de Medula Renal inteiro em Zebrafish Adulto

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

Biologia

Actin Co-Sedimentation Assay; for the Analysis of Protein Binding to F-Actin

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates tension and helps maintains cellular shape.  Although the actin cytoskeleton is a rigid structure, it is a dynamic structure that is constantly remodeling.  A number of proteins can bind to the actin cytoskeleton.  The binding of a particular protein to F-actin is often desired to support cell biological observations or to further understand dynamic processes due to remodeling of the actin cytoskeleton. The actin co-sedimentation assay is an in vitro assay routinely used to analyze the binding of specific proteins or protein domains with F-actin.  The basic principles of the assay involve an incubation of the protein of interest (full length or domain of) with F-actin, ultracentrifugation step to pellet F-actin and analysis of the protein co-sedimenting with F-actin.  Actin co-sedimentation assays can be designed accordingly to measure actin binding affinities and in competition assays.

Proteins bind to filamentous actin (F-actin) through distinct actin binding modules. In this video we demonstrate the procedure of actin co-sedimentation, which is an in vitro assay routinely used to analyze proteins or specific domains that bind F-actin.

Actina Ensaio Co Sedimentação; para a Análise da proteína de ligação a F-Actina

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates ...

Generating Chimeric Zebrafish Embryos by Transplantation

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an organism that contains cells from more than one animal; mosaics are one type of chimera in which cells from more than one genotype are mixed, usually wild-type and mutant. In the zebrafish, chimeras can be readily made by transplantation of cells from a donor embryo into a host embryo at the appropriate embryonic stage. Labeled donor cells are generated by injection of a lineage marker, such as a fluorescent dye, into the one-cell stage embryo. Labeled donor cells are removed from donor embryos and introduced into unlabeled host embryos using an oil-controlled glass pipette mounted on either a compound or dissecting microscope. Donor cells can in some cases be targeted to a specific region or tissue of the developing blastula or gastrula stage host embryo by choosing a transplantation site in the host embryo based on well-established fate maps.

A step-by-step guide to generating targeted chimeric zebrafish embryos by transplantation at the blastula or gastrula stage.

A criação de embriões quiméricos Zebrafish por Transplante

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an ...

Microdissection of Zebrafish Embryonic Eye Tissues

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 fertilization (dpf), the larvae will show the first visual response. Many genes have been identified to control a proper eye development, but we are far from a complete understanding of the underlying genetic architecture. Whole genome gene expression profiling is a useful tool to elucidate genetic regulatory network for eye development. However, the small size of the embryonic eye in zebrafish makes it challenging to obtain intact and pure eye tissues for expression analysis. For example, the anterior-posterior length of the eye between day 2 and 3 is only approximately 200-300 &mu;m, while the diameter of the lens is less 100 &mu;m. Also, the retinal pigment epithelium (RPE) underlying the retina is just a single-layer epithelium. While gene expression profiles can be obtained from the whole embryo, they do not accurately represent the expression of these tissues. Therefore pure tissue must be obtained for a successful gene expression profiling of eye development. To address this issue, we have developed an approach to microdissect intact retina and retina with RPE attached from 1-3 dpf, which cover major stages of eye morphogenesis. All procedures can be done with fine forceps and general laboratory supplies under standard stereomicroscopes. For retinal dissection, the single-layer RPE is removed and peeled off by brushing action and the preferential adherence of the RPE remnants to the surface of the culture plate for dissection. For RPE-attached retinal dissection, the adherence of RPE to the dissection plate is removed before the dissection so that the RPE can be completely preserved with the retina. A careful lifting action of this tissue can efficiently separate the presumptive choroid and sclera. The lens can be removed in both cases by a chemically etched tungsten needle. In short, our approach can obtain intact eye tissues and has been successfully utilized to study tissue-specific expression profiles of zebrafish retina1, 2 and retinal pigment epithelium3.

This article describes an approach to microdissect zebrafish retinas with and without retinal pigment epithelium attached, from one to three days postfertilization embryos.

Microdissecção de tecidos oculares Zebrafish embrionárias

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 ...

Dechorionation of Medaka Embryos and Cell Transplantation for the Generation of Chimeras

Medaka is a small egg-laying freshwater fish that allows both genetic and embryological analyses and is one of the three vertebrate model organisms in which genome-wide phenotype-driven mutant screens were carried out 1. Divergence of functional overlap of related genes between medaka and zebrafish allows identification of novel phenotypes that are unidentifiable in a single species 2, thus medaka and zebrafish are complementary for genetic dissection of the vertebrate genome functions. Manipulation of medaka embryos, such as dechorionation, mounting embryos for imaging and cell transplantation, are key procedures to work on both medaka and zebrafish in a laboratory. Cell transplantation examines cell autonomy of medaka mutations. Chimeras are generated by transplanting labeled cells from donor embryos into unlabeled recipient embryos. Donor cells can be transplanted to specific areas of the recipient embryos based on the fate maps 3 so that clones from transplanted cells can be integrated in the tissue of interest during development. Due to the hard chorion and soft embryos, manipulation of medaka embryos is more involved than in zebrafish. In this video, we show detailed procedures to manipulate medaka embryos.

Due to the hard chorion and soft embryos, manipulation of medaka embryos is more involved than in zebrafish. This video shows step-by-step procedures for how to manipulate medaka embryos, including dechorionation, mounting in agarose for imaging and cell transplantation for the production of chimeras. These procedures are essential to use medaka and zebrafish in a laboratory to take full advantage of their complementary features for the genetic dissection of vertebrate genome functions.

Dechorionation de Embriões Medaka e Transplante de Células de Geração de Quimeras

Medaka is a small egg-laying freshwater fish that allows both genetic and embryological analyses and is one of the three vertebrate model organisms in ...

Multicolor Time-lapse Imaging of Transgenic Zebrafish: Visualizing Retinal Stem Cells Activated by Targeted Neuronal Cell Ablation

High-resolution time-lapse imaging of living zebrafish larvae can be utilized to visualize how biological processes unfold (for review see 1). Compound transgenic fish which express different fluorescent reporters in neighboring cell types provide a means of following cellular interactions 2 and/or tissue-level responses to experimental manipulations over time. In this video, we demonstrate methods that can be used for imaging multiple transgenically labeled cell types serially in individual fish over time courses that can span from minutes to several days. The techniques described are applicable to any study seeking to correlate the "behavior" of neighboring cells types over time, including: 1) serial 'catch and release' methods for imaging a large number of fish over successive days, 2) simplified approaches for separating fluorophores with overlapping excitation/emission profiles (e.g., GFP and YFP), 3) use of hypopigmented mutant lines to extend the time window available for high-resolution imaging into late larval stages of development, 4) use of membrane targeted fluorescent reporters to reveal fine morphological detail of individual cells as well as cellular details in larger populations of cells, and 5) a previously described method for chemically-induced ablation of transgenically targeted cell types; i.e., nitroreductase (NTR) mediated conversion of prodrug substrates, such as metronidazole (MTZ), to cytotoxic derivatives 3,5.
As an example of these approaches, we will visualize the ablation and regeneration of a subtype of retinal bipolar neuron within individual fish over several days. Simultaneously we will monitor several other retinal cell types, including neighboring non-targeted bipolar cells and potential degeneration-stimulated retinal stem cells (i.e., M&#971;ller glia). This strategy is being applied in our lab to characterize cell- and tissue-level (e.g., stem cell niche) responses to the selective loss and regeneration of targeted neuronal cell types.

In this video, techniques for multicolor confocal time-lapse imaging and targeted cell ablation are provided. Time-lapse imaging is used to monitor the behavior of multiple cell types of interest in vivo. Targeted cell ablation facilitates the study neural circuit function and cell-specific neuronal regeneration paradigms.

Multicolor imagem em tempo-lapso de Transgênicos Zebrafish: Visualizando Células-Tronco da retina Ativado por Ablação célula-alvo Neuronal

High-resolution time-lapse imaging of living zebrafish larvae can be utilized to visualize how biological processes unfold (for review see 1). Compound ...

Primary Cell Cultures from Drosophila Gastrula Embryos

Here we describe a method for preparing and culturing primary cells dissociated from Drosophila gastrula embryos. In brief, a large amount of staged embryos from young and healthy flies are collected, sterilized, and then physically dissociated into a single cell suspension using a glass homogenizer. After being plated on culture plates or chamber slides at an appropriate density in culture medium, these cells can further differentiate into several morphologically-distinct cell types, which can be identified by their specific cell markers. Furthermore, we present conditions for treating these cells with double stranded (ds) RNAs to elicit gene knockdown. Efficient RNAi in Drosophila primary cells is accomplished by simply bathing the cells in dsRNA-containing culture medium. The ability to carry out effective RNAi perturbation, together with other molecular, biochemical, cell imaging analyses, will allow a variety of questions to be answered in Drosophila primary cells, especially those related to differentiated muscle and neuronal cells.

Primary Cell Cultures from Drosophila Gastrula Embryos

We provide a detailed protocol for preparing primary cells dissociated from Drosophila embryos. The ability to carry out the effective RNAi perturbation, together with other molecular, biochemical and cell imaging methods will allow a variety of questions to be addressed in Drosophila primary cells.

Culturas de células primárias de Drosophila Os embriões Gástrula

Here we describe a method for preparing and culturing primary cells dissociated from Drosophila gastrula embryos.   In brief, a large amount of staged ...

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 ...

Quantifying the Frequency of Tumor-propagating Cells Using Limiting Dilution Cell Transplantation in Syngeneic Zebrafish

Self-renewing cancer cells are the only cell types within a tumor that have an unlimited ability to promote tumor growth, and are thus known as tumor-propagating cells, or tumor-initiating cells. It is thought that targeting these self-renewing cells for destruction will block tumor progression and stop relapse, greatly improving patient prognosis1. The most common way to determine the frequency of self-renewing cells within a tumor is a limiting dilution cell transplantation assay, in which tumor cells are transplanted into recipient animals at increasing doses; the proportion of animals that develop tumors is used the calculate the number of self-renewing cells within the original tumor sample2, 3. Ideally, a large number of animals would be used in each limiting dilution experiment to accurately determine the frequency of tumor-propagating cells. However, large scale experiments involving mice are costly, and most limiting dilution assays use only 10-15 mice per experiment. 
Zebrafish have gained prominence as a cancer model, in large part due to their ease of genetic manipulation and the economy by which large scale experiments can be performed. Additionally, the cancer types modeled in zebrafish have been found to closely mimic their counterpart human disease4. While it is possible to transplant tumor cells from one fish to another by sub-lethal irradiation of recipient animals, the regeneration of the immune system after 21 days often causes tumor regression5. The recent creation of syngeneic zebrafish has greatly facilitated tumor transplantation studies 6-8. Because these animals are genetically identical, transplanted tumor cells engraft robustly into recipient fish, and tumor growth can be monitored over long periods of time. Syngeneic zebrafish are ideal for limiting dilution transplantation assays in that tumor cells do not have to adapt to growth in a foreign microenvironment, which may underestimate self-renewing cell frequency9, 10. Additionally, one-cell transplants have been successfully completed using syngeneic zebrafish8 and several hundred animals can be easily and economically transplanted at one time, both of which serve to provide a more accurate estimate of self-renewing cell frequency.
Here, a method is presented for creating primary, fluorescently-labeled T-cell acute lymphoblastic leukemia (T-ALL) in syngeneic zebrafish, and transplanting these tumors at limiting dilution into adult fish to determine self-renewing cell frequency. While leukemia is provided as an example, this protocol is suitable to determine the frequency of tumor-propagating cells using any cancer model in the zebrafish.

Limiting dilution cell transplantation assays are used to determine the frequency of tumor-propagating cells. This protocol describes a method for generating syngeneic zebrafish that develop fluorescently-labeled leukemia and details how to isolate and transplant these leukemia cells at limiting dilution into the peritoneal cavity of adult zebrafish.

Quantificar a freqüência de Tumor-propagação células usando Transplante de Células Limitando diluição em singênicos Zebrafish

Self-renewing cancer cells are the only cell types within a tumor that have an unlimited ability to promote tumor growth, and are thus known as ...

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.

Imunomarcação de Dissecada Coração Zebrafish embrionárias

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