Name: single-cell photoconversion in living intact zebrafish
Uploaded: 2018-03-19T14:00:00.000+00:00
Duration: 9 min 49 s
Description: Watch this Scientific Journal Video about Single-cell Photoconversion in Living Intact Zebrafish at JoVE.com

Agradecemos a Bernard Kulemaka e membros do laboratório de Smith para seus comentários úteis e orientação de reagente, Sam Connell e Brent Redford de 3i para responder perguntas de imagem e Deborah Bang, Karen Heed e Kay Stewart para cuidados de zebrafish. Este trabalho foi financiado pela Universidade de Notre Dame, a Elizabeth e Michael Gallagher Family, Alfred P. Sloan Foundation, centro de investigação de Zebrafish na Universidade de Notre e centro de células-tronco e medicina regenerativa da Universidade de Notre Dame. Todos os estudos animais foram feitos em conformidade com a Universidade de Notre Dame IACUC ao Dr. Cody Smith.

Todos os estudos em animais foram aprovados pela Universidade de Notre Dame institucional Cuidado Animal e Comissão de utilização.
1. preparação da amostra de Zebrafish
<ol><li>Coloque um macho adulto e um adulto feminino Tg (proteína conversível) para a câmara de acasalamento por procedimentos-padrão13. Neste manuscrito, use Tg(sox10:eos) peixe9 por causa do acesso, mas outras linhas transgénicas com proteína de photoconvertible pode ser igualmente utilizado. Configure mais de uma câmara no caso de peixe não fazer lay. Permitir que os peixes que permanecem na câmara durante a noite.</li>
	<li>Na manhã seguinte, colete ovos em caixas de Petri 100 mm. Permitem a ovos amadurecer-se à fertilização de pós 24h (hpf) antes de triagem.</li>
	<li>Se animais acima eram heterozigotos para o transgene, pratos de hpf tela 24 Tg(sox10:eos) + embriões com uma fonte de luz nm 488 e GFP filtram conjuntos em um microscópio de dissecação. Tg(sox10:eos) + embriões de isolar e permitir para amadurecer-se 48 hpf.</li>
	<li>Dechorionate embriões manualmente com uma agulha ou pinça.</li>
	<li>Preparar e 5 mL de solução de ponto de agarose de baixo ponto de fusão de 0,8% no microondas.<ol>
<li>Uma vez que a agarose é frio ao toque, coloque 3-4 anestesiados Tg (sox10:eos) + 48 peixe hpf no centro de um vidro de 10mm-lamela inferior placa de Petri.</li>
		<li>Adicione suficiente agarose para cobrir a superfície da lamela, cerca de 1 mL. Use uma agulha de sonda para organizar peixe em seus lados. Permitir que a agarose solidificar para garantir a montagem de animais. Pode ser necessário para continuamente re-organizar o zebrafish até o ágar solidifies14. Solidificação leva aproximadamente 2 minutos.</li>
	</ol>
</li>
	<li>Depois que a agarose solidificou-se por 2 min, adicione lentamente o meio de embrião contendo 0,02% éster de ácido aminobenzoico (tricaina) para prato até a superfície inferior do ágar e prato está submersa. Isto deve ser de aproximadamente 3mL.</li>
</ol>2. microscópio montagem e pre-conversão imagens
<ol><li>Confocal software aberto e selecionar os windows captura e foco [Figura 1]. Sob a janela de captura, selecione a configuração de conversão específicas do laboratório de imagem sob a captura de configuração drop-down guia [Figura 1]. Aqui, a configuração específica do laboratório é chamada de "peixe Imaging".</li>
	<li>Coloque a amostra no escopo confocal e colocar em foco usando o curso e os botões de ajuste fino.</li>
	<li>Abra a janela de foco e localizar a região desejada de interesse (ou seja, o gânglio da raiz dorsal).</li>
	<li>Selecione o laser c488 sob o menu filtro definido. Definir a exposição a 300 ms, poder para 5 laser e intensificar a 75 [Figura 2].</li>
	<li>Marque a caixa 3D na seção tipo de captura . Na seção de captura 3D , selecione usar atual posição e verificar o intervalo ao redor de corrente. Na mesma seção, defina o intervalo de 35 anos, o número de aviões a 36 e o tamanho da etapa 1. O intervalo pode ser aumentado ou diminuído para acomodar para a profundidade da área de imagem. Para a medula espinhal, um valor de intervalo entre 35-40 pilhas normalmente é suficiente [Figura 5].</li>
	<li>Selecione o local atual [Figura 5].</li>
	<li>Clique em Iniciar na parte inferior da janela de captura para adquirir a imagem.</li>
</ol>3. single-cell Photoconversion
<ol><li>Confocal software aberto e selecionar os windows captura e foco [Figura 1]. Sob a janela de captura, selecione a configuração de conversão específicas do laboratório de imagem sob a captura de configuração drop-down guia [Figura 1]. Aqui, a configuração específica do laboratório é chamada de "Peixe ablate chip completo."</li>
	<li>Selecione o laser c488 e c541 sob o menu filtro definido. Se não utilizar o mesmo software de microscópio, encontre o menu para selecionar diferentes lasers e selecione o 488 nm e 541 lasers de nm. Definir os riscos relativos a 300 ms, poder para 5 laser e intensificar a 75 [Figura 2]. Essas configurações do laser são selecionadas com base na produção suficiente sinal fluorescente sem causar fotobranqueamento ou toxicidade. Se toxicidade ou fotobranqueamento é visualizado, reduza a potência do laser ou exposição.</li>
	<li>Abra a janela de foco e clique na guia photomanipulation na janela de foco. Ajuste os parâmetros do laser em conformidade. Mudar a potência da pilha do laser para 2 e clique em ir. Alterar o tamanho de bloco de Raster para 1 e clique em definir. Altere o tamanho de clique duplo para 4. Altere a linha de laser para v405 [Figura 3].</li>
	<li>Abra as configurações de captura avançada na janela de captura. Selecione a guia photomanipulation e alterar as repetições de clique duplo para 2. Clique Okey [Figura 4].</li>
	<li>Selecione a guia XY na janela de foco. Verifique os parâmetros do laser da etapa 2 na guia photomanipulation [Figura 3, Figura 4]. Definir configurações do laser para photoconvert a célula de interesse sem photoconversion das células circundantes.<ol>
<li>Se houver photoconversion de células adjacentes, reduza a potência do laser. Se photoconversion de células não ocorre, poderes do laser podem ser aumentados. Idealmente, conjunto potência do laser para photoconvert apenas a região de interesse e não áreas circunvizinhas.</li>
	</ol>
</li>
	<li>Marque a caixa de timelapse sob o tipo de captura. Em seguida, clique em Iniciar [figura 6A].</li>
	<li>Uma vez que abre a janela de timelapse ao vivo, selecione a ferramenta círculo na barra superior [Figura 7]</li>
	<li>Desenhe um círculo na região centermost da célula. O círculo desenhado com o botão direito, selecione a região FRAPe aguarde 3 segundos. A área selecionada deve tornar-se redutor [Figura 8]. Clique em parar captura.</li>
	<li>Se mais de um animal de imagem, volte para o guia XY no foco menu e selecione posição 2. Em seguida, repita etapas 4.1-4.6.</li>
	<li>Para converter uma população de células, segui os parâmetros de protocolo e laser para etapas 4.1-4.4 exceto em vez de um círculo para FRAP a região de interesse, use a ferramenta de linha de desenho. Desenhar uma linha na região de interesse e FRAP região usando os mesmos parâmetros listados acima.</li>
</ol>4. post-photoconversion Imaging
<ol><li>Uma vez que todos os pontos são photoconverted. Selecione a pilha de imagem padrão de laboratório específicas configuração descrita na precoversion de imagem passo 3. Isto é encontrado sob a captura de configuração drop-down guia na janela de captura [Figura 5].</li>
	<li>Selecione o laser c488 e definir a exposição a 300ms, poder para 5 laser e intensificar a 75 [Figura 2].</li>
	<li>Selecione o laser c541 encontrado sob o mesmo menu como o laser c488. Definir a exposição de 500 ms, poder para 10 laser e intensificar a 75 [Figura 9].</li>
	<li>Marque a caixa 3D na seção tipo de captura . Na seção de captura 3D , selecione usar atual posição e verificar o intervalo ao redor de corrente. Na mesma seção, defina o intervalo de 35 anos, o número de aviões a 36 e o tamanho da etapa 1. O número de série pode aumentar ou diminuir para acomodar a desejada profundidade de imagem [Figura 5].</li>
	<li>Se houver vários pontos no guia de foco XY, selecione a opção lista multiponto na janela de captura. Se não, selecione o local atual.</li>
	<li>Clique em Iniciar na parte inferior da janela de captura para adquirir a imagem.</li>
</ol>

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Em tecidos complexos, distintos tipos de células organizam em domínios específicos. Recentemente, as técnicas têm sido utilizadas para células individuais de etiqueta dentro destes tecidos grandes estruturas1,2,3. Aqui vamos demonstrar duas técnicas que podem ser utilizadas da mesma forma para visualizar tanto interações célula única e interações de população celular dentro de tecidos complexos. A vantagem da téc...

Várias células distintas interagem para construir e manter o complexos tecidos animais e vegetais. Estas células são frequentemente intercalados e difícil de distinguir de vizinhos em um nível de célula única sem microscopia de alta resolução que exigem a fixação do tecido. No entanto, para compreender a forma como estes tecidos, são mantidas e tornar-se doente, tem sido essencial para investigar como single as células dentro do tecido estão interagindo ao longo do tempo. Idealmente, estas experiências exigem a rotulagem de células únicas dentro de um tecido de forma não-invasiva, sem a exigência de fixação. Os cientistas agora desenvolveram inúmeras técnicas para realizar esta tarefa1,2,3,4.
A descoberta e a implementação da proteína medusas verde fluorescente (GFP) foi uma abordagem interessante que permitiu para a rotulagem de células distintas em um ambiente de tecido1. Usando promotores de célula específica, é possível geneticamente, selecionar um subconjunto de células que são rotulados1. Alternativamente, viral induzida expressão de GFP pode ser utilizada para usuário-selecionado expressão de GFP3,4. Embora bastante útil, expressão mediada genética de GFP não permite expressão selecionado pelo usuário dentro de um subconjunto de células no tecido; e a expressão viral de GFP, apesar de vantajoso, pode ser invasiva. Com o advento de técnicas inteligentes como Brainbow expressar proteínas fluorescentes distintas mais escassa dentro de tecidos e derivados GFP, tornou-se possível visualizar células únicas e as interações entre eles em tecido complexo2, 5. no entanto, essas abordagens rotular as células de uma forma aleatória. Se o experimento desejado requer a visualização de uma única célula ou a população de células é definido pelo experimentador, são, portanto, limitados. Com tais experiências, seria vantajoso ter uma proteína fluorescente geneticamente expressa que pode ser manipulada para distinguir, de forma única célula, que de outras células não-fluorescente fluorescentes.
Para atingir esse objetivo e visualizar a biologia celular de células únicas dentro de um tecido vivo complexo, a comunidade científica usa única célula photoconversion de proteínas fluorescentes distintas6,7,8. Usando geneticamente controlado a expressão de uma proteína de photoconvertible (i.e., eos, kaede, etc.) que transita de um verde para vermelho estado fluorescente quando exposto aos raios UV (488 nm) a luz, podemos distinguir uma única célula de sua fluorescente etiquetadas vizinhos de7,6,8. Esta abordagem utiliza um aparelho ligado ao nosso microscópio confocal que pode direcionar a luz de uma pilha de laser para uma região de difração limitada de interesse. Com esta técnica, podemos rotular ou células únicas ou maiores populações em uma maneira definida pelo usuário9,10,11. A técnica é minimamente invasiva em comparação com injeções de célula única de GFP viral. Como uma prova de conceito, mostramos que podemos photoconvert células únicas dentro de um gânglio no sistema nervoso periférico e as maiores populações de photoconvert como células localizadas no lado ventral da medula espinhal9,10, 11,12. Podemos então Visualizar estas photoconverted populações de células 24h mais tarde para ganhar a introspecção em seu movimento e diferenciação durante o desenvolvimento.

<table><tbody><tr><td>&lt;font class=&quot;font5&quot;&gt;Tg(&lt;em&gt;sox10:eos&lt;/em&gt;)&lt;/font&gt;&lt;font class=&quot;font0&quot;&gt; zebrafish animals&lt;/font&gt;</td><td></td><td></td><td>Fish were obtained and crossed from the fish facility at the University of Notre Dame</td></tr><tr><td>100 X 15 mm petri dish</td><td>VWR</td><td>25384-302</td><td></td></tr><tr><td>Embryo medium</td><td></td><td></td><td>Embryo medium is made weekly and provided by the fish facility at the University of Notre Dame containing 5L RO water, 30uL methylene blue, and 200mL salt stock.</td></tr><tr><td>0.8% Low Melting Point Agarose</td><td>dot scientific inc</td><td>9012-36-6</td><td></td></tr><tr><td>35 X 10 mm glass-coverslip bottom petri dish</td><td>Ted Pella Inc.</td><td>14021-20</td><td></td></tr><tr><td>Needle dissecting probe</td><td></td><td></td><td></td></tr><tr><td>0.002% 3-aminobenzoic acid ester (Tricaine)</td><td>Fluka analytical</td><td>A5040-250G</td><td></td></tr><tr><td>Fluorescent Dissecting Microscope with GFP filters</td><td>Zeiss Axiozoom</td><td></td><td></td></tr><tr><td>Confocal microscope with lasers to excite GFP and RFP filter sets</td><td>3i spinning disk confocal</td><td></td><td></td></tr><tr><td>UV light source (laser) for photoconversion</td><td>405 nm laser</td><td></td><td></td></tr><tr><td>Slidebook software</td><td>3i</td><td></td><td></td></tr><tr><td>Methylene blue</td><td>Kordon</td><td></td><td></td></tr></tbody></table>

single-cell photoconversion in living intact zebrafish

Tecidos animais e vegetais é composto de populações distintas de células. Estas células interagem ao longo do tempo para construir e manter o tecido e podem causar doenças quando interrompido. Os cientistas desenvolveram técnicas inteligentes para investigar características e dinâmica natural dessas células no tecido intacto por expressar proteínas fluorescentes em subconjuntos de células. No entanto, às vezes, experiências exigem mais selecionada visualização de células dentro do tecido, às vezes a forma unicelular ou população de células. Para alcançar este objectivo e Visualizar células únicas dentro de uma população de células, os cientistas têm utilizado a célula única photoconversion de proteínas fluorescentes. Para demonstrar essa técnica, mostramos aqui como direcionar a luz UV para uma célula Eos-expressando um interesse de uma intacta, vivendo zebrafish. Nós então imagem essas células de Eos+ photoconverted 24h depois para determinar como eles mudaram no tecido. Descrevemos duas técnicas: única célula photoconversion e photoconversions das populações de células. Estas técnicas podem ser usadas para visualizar interações célula-célula, célula-destino e diferenciação e migrações de célula, tornando-se uma técnica que é aplicável em numerosas questões biológicas.

Photoconversion de proteínas fluorescentes pode ser usado para rotular células distintas dentro de um tecido de6. Para demonstrar isso, Tg(sox10:eos) peixe9 foram usados para expressar a proteína photoconvertible Eos sob as sequências reguladoras de sox10. Os animais Tg(sox10:eos) em 48 hpf foram montados primeiro e então fotografada para detectar qualquer photoconversion não-específicos que possam ter ocorr...

Watch this Scientific Journal Video about Single-cell Photoconversion in Living Intact Zebrafish at JoVE.com

Single-cell Photoconversion in Living Intact Zebrafish

Aqui, apresentamos um protocolo para mostrar como célula photoconversion é conseguida através da exposição UV para áreas específicas, expressando a proteína fluorescente, Eos, em animais vivos.

Photoconversion de célula única no Zebrafish intacta vida

Animal and plant tissue is composed of distinct populations of cells. These cells interact over time to build and maintain the tissue and can cause ...

single-cell-photoconversion-in-living-intact-zebrafish

Universidad San Sebastian

Research

JoVE Journal

Developmental Biology

6.0K visualizações.  University of Notre Dame. Aqui, apresentamos um protocolo para mostrar como célula photoconversion é conseguida através da exposição UV para áreas específicas, expressando a proteína fluorescente, Eos, em animais vivos.

Vídeo: Single-cell Photoconversion in Living Intact Zebrafish

Measuring Protein Stability in Living Zebrafish Embryos Using Fluorescence Decay After Photoconversion (FDAP)

Protein stability influences many aspects of biology, and measuring the clearance kinetics of proteins can provide important insights into biological systems. In FDAP experiments, the clearance of proteins within living organisms can be measured. A protein of interest is tagged with a photoconvertible fluorescent protein, expressed in vivo and photoconverted, and the decrease in the photoconverted signal over time is monitored. The data is then fitted with an appropriate clearance model to determine the protein half-life. Importantly, the clearance kinetics of protein populations in different compartments of the organism can be examined separately by applying compartmental masks. This approach has been used to determine the intra- and extracellular half-lives of secreted signaling proteins during zebrafish development. Here, we describe a protocol for FDAP experiments in zebrafish embryos. It should be possible to use FDAP to determine the clearance kinetics of any taggable protein in any optically accessible organism.

Measuring Protein Stability in Living Zebrafish Embryos Using Fluorescence Decay After Photoconversion FDAP

Protein levels in cells and tissues are often tightly regulated by the balance of protein production and clearance. Using Fluorescence Decay After Photoconversion (FDAP), the clearance kinetics of proteins can be experimentally measured in vivo.

Medir a estabilidade da proteína em Viver embriões Zebrafish Usando Fluorescência Decay Após Fotoconversão (FDAP)

Protein stability influences many aspects of biology, and measuring the clearance kinetics of proteins can provide important insights into biological ...

Biologia do Desenvolvimento

Imaging Subcellular Structures in the Living Zebrafish Embryo

In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such imaging experiments in higher vertebrates such as mammals generally requires surgical access to the system under study. The optical accessibility of embryonic and larval zebrafish allows such invasive procedures to be circumvented and permits imaging in the intact organism. Indeed the zebrafish is now a well-established model to visualize dynamic cellular behaviors using in vivo microscopy in a wide range of developmental contexts from proliferation to migration and differentiation. A more recent development is the increasing use of zebrafish to study subcellular events including mitochondrial trafficking and centrosome dynamics. The relative ease with which these subcellular structures can be genetically labeled by fluorescent proteins and the use of light microscopy techniques to image them is transforming the zebrafish into an in vivo model of cell biology. Here we describe methods to generate genetic constructs that fluorescently label organelles, highlighting mitochondria and centrosomes as specific examples. We use the bipartite Gal4-UAS system in multiple configurations to restrict expression to specific cell-types and provide protocols to generate transiently expressing and stable transgenic fish. Finally, we provide guidelines for choosing light microscopy methods that are most suitable for imaging subcellular dynamics.

Imaging the dynamic behavior of organelles and other subcellular structures in vivo can shed light on their function in physiological and disease conditions. Here, we present methods for genetically tagging two organelles, centrosomes and mitochondria, and imaging their dynamics in living zebrafish embryos using wide-field and confocal microscopy.

Imagiologia estruturas celulares no embrião vivo Zebrafish

In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such ...

Tracking Cells in GFP-transgenic Zebrafish Using the Photoconvertible PSmOrange System

The rapid development of transparent zebrafish embryos (Danio rerio) in combination with fluorescent labelings of cells and tissues allows visualizing developmental processes as they happen in the living animal. Cells of interest can be labeled by using a tissue specific promoter to drive the expression of a fluorescent protein (FP) for the generation of transgenic lines. Using fluorescent photoconvertible proteins for this purpose additionally allows to precisely follow defined structures within the expression domain. Illuminating the protein in the region of interest, changes its emission spectrum and highlights a particular cell or cell cluster leaving other transgenic cells in their original color. A major limitation is the lack of known promoters for a large number of tissues in the zebrafish. Conversely, gene- and enhancer trap screens have generated enormous transgenic resources discretely labeling literally all embryonic structures mostly with GFP or to a lesser extend red or yellow FPs. An approach to follow defined structures in such transgenic backgrounds would be to additionally introduce a ubiquitous photoconvertible protein, which could be converted in the cell(s) of interest. However, the photoconvertible proteins available involve a green and/or less frequently a red emission state1 and can therefore often not be used to track cells in the FP-background of existing transgenic lines. To circumvent this problem, we have established the PSmOrange system for the zebrafish2,3. Simple microinjection of synthetic mRNA encoding a nuclear form of this protein labels all cell nuclei with orange/red fluorescence. Upon targeted photoconversion of the protein, it switches its emission spectrum to far red. The quantum efficiency and stability of the protein makes PSmOrange a superb cell-tracking tool for zebrafish and possibly other teleost species.

We established the photoconvertible PSmOrange system as a powerful, straight-forward and cost inexpensive tool for in vivo cell tracking in GFP transgenic backgrounds. This protocol describes its application in the zebrafish model system.

Acompanhando as células GFP em peixes-zebra transgénicos Usando o Sistema Photoconvertible PSmOrange

The rapid development of transparent zebrafish embryos (Danio rerio) in combination with fluorescent labelings of cells and tissues allows visualizing ...

Culture of Adult Transgenic Zebrafish Retinal Explants for Live-cell Imaging by Multiphoton Microscopy

An endogenous regeneration program is initiated by M&#252;ller glia in the adult zebrafish (Danio rerio) retina following neuronal damage and death. The M&#252;ller glia re-enter the cell cycle and produce neuronal progenitor cells that undergo subsequent rounds of cell divisions and differentiate into the lost neuronal cell types. Both M&#252;ller glia and neuronal progenitor cell nuclei replicate their DNA and undergo mitosis in distinct locations of the retina, i.e. they migrate between the basal Inner Nuclear Layer (INL) and the Outer Nuclear Layer (ONL), respectively, in a process described as Interkinetic Nuclear Migration (INM). INM has predominantly been studied in the developing retina. To examine the dynamics of INM in the adult regenerating zebrafish retina in detail, live-cell imaging of fluorescently-labeled M&#252;ller glia/neuronal progenitor cells is required. Here, we provide the conditions to isolate and culture dorsal retinas from Tg[gfap:nGFP]mi2004 zebrafish that were exposed to constant intense light for 35 h. We also show that these retinal cultures are viable to perform live-cell imaging experiments, continuously acquiring z-stack images throughout the thickness of the retinal explant for up to 8 h using multiphoton microscopy to monitor the migratory behavior of gfap:nGFP-positive cells. In addition, we describe the details to perform post-imaging analysis to determine the velocity of apical and basal INM. To summarize, we established conditions to study the dynamics of INM in an adult model of neuronal regeneration. This will advance our understanding of this crucial cellular process and allow us to determine the mechanisms that control INM.

Zebrafish retinal regeneration has mostly been studied using fixed retinas. However, dynamic processes such as interkinetic nuclear migration occur during the regenerative response and require live-cell imaging to investigate the underlying mechanisms. Here, we describe culture and imaging conditions to monitor Interkinetic Nuclear Migration (INM) in real-time using multiphoton microscopy.

Cultura do Adulto Transgênicos Zebrafish Retinal explantes for Imaging Em células vivas, por Multiphoton Microscopia

An endogenous regeneration program is initiated by M&#252;ller glia in the adult zebrafish (Danio rerio) retina following neuronal damage and death. The ...

Following Endocardial Tissue Movements via Cell Photoconversion in the Zebrafish Embryo

During embryogenesis, cells undergo dynamic changes in cell behavior, and deciphering the cellular logic behind these changes is a fundamental goal in the field of developmental biology. The discovery and development of photoconvertible proteins have greatly aided our understanding of these dynamic changes by providing a method to optically highlight cells and tissues. However, while photoconversion, time-lapse microscopy, and subsequent image analysis have proven to be very successful in uncovering cellular dynamics in organs such as the brain or the eye, this approach is generally not used in the developing heart due to challenges posed by the rapid movement of the heart during the cardiac cycle. This protocol consists of two parts. The first part describes a method for photoconverting and subsequently tracking endocardial cells (EdCs) during zebrafish atrioventricular canal (AVC) and atrioventricular heart valve development. The method involves temporally stopping the heart with a drug in order for accurate photoconversion to take place. Hearts are allowed to resume beating upon removal of the drug and embryonic development continues normally until the heart is stopped again for high-resolution imaging of photoconverted EdCs at a later developmental time point. The second part of the protocol describes an image analysis method to quantify the length of a photoconverted or non-photoconverted region in the AVC in young embryos by mapping the fluorescent signal from the three-dimensional structure onto a two-dimensional map. Together, the two parts of the protocol allows one to examine the origin and behavior of cells that make up the zebrafish AVC and atrioventricular heart valve, and can potentially be applied for studying mutants, morphants, or embryos that have been treated with reagents that disrupt AVC and/or valve development.

This protocol describes a method for the photoconversion of Kaede fluorescent protein in endocardial cells of the living zebrafish embryo that enables the tracking of endocardial cells during atrioventricular canal and atrioventricular heart valve development.

Seguindo os movimentos de tecido endocárdico através de célula Photoconversion no embrião Zebrafish

During embryogenesis, cells undergo dynamic changes in cell behavior, and deciphering the cellular logic behind these changes is a fundamental goal in the ...

Culture and Transfection of Zebrafish Primary Cells

Zebrafish embryos are transparent and develop rapidly outside the mother, thus allowing for excellent in vivo imaging of dynamic biological processes in an intact and developing vertebrate. However, the detailed imaging of the morphologies of distinct cell types and subcellular structures is limited in whole mounts. Therefore, we established an efficient and easy-to-use protocol to culture live primary cells from zebrafish embryos and adult tissue.
In brief, 2 dpf zebrafish embryos are dechorionated, deyolked, sterilized, and dissociated to single cells with collagenase. After a filtration step, primary cells are plated onto glass bottom dishes and cultivated for several days. Fresh cultures, as much as long term differenciated ones, can be used for high resolution confocal imaging studies. The culture contains different cell types, with striated myocytes and neurons being prominent on poly-L-lysine coating. To specifically label subcellular structures by fluorescent marker proteins, we also established an electroporation protocol which allows the transfection of plasmid DNA into different cell types, including neurons. Thus, in the presence of operator defined stimuli, complex cell behavior, and intracellular dynamics of primary zebrafish cells can be assessed with high spatial and temporal resolution. In addition, by using adult zebrafish brain, we demonstrate that the described dissociation technique, as well as the basic culturing conditions, also work for adult zebrafish tissue.

We present an efficient and easy-to-use protocol for preparing primary cell cultures of zebrafish embryos for transfection and live cell imaging as well as a protocol to prepare primary cells from adult zebrafish brain.

Cultura e transfecção de células primárias de Zebrafish

Zebrafish embryos are transparent and develop rapidly outside the mother, thus allowing for excellent in vivo imaging of dynamic biological processes in ...

Two-Photon-Based Photoactivation in Live Zebrafish Embryos

Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic development, cellular signaling and adult physiology. In this respect, the use of multi-photon microscopy enables quantitative photoactivation of a given light responsive agent in deep tissues at a single cell resolution. As zebrafish embryos are optically transparent, their development can be monitored in vivo. These traits make the zebrafish a perfect model organism for controlling the activity of a variety of chemical agents and proteins by focused light. Here we describe the use of two-photon microscopy to induce the activation of chemically caged fluorescein, which in turn allows us to follow cell's destiny in live zebrafish embryos. We use embryos expressing a live genetic landmark (GFP) to locate and precisely target any cells of interest. This procedure can be similarly used for precise light induced activation of proteins, hormones, small molecules and other caged compounds.

Multiphoton microscopy allows control of low energy photons with deep optical penetration and reduced phototoxicity. We describe the use of this technology for live cell labeling in zebrafish embryos. This protocol can be readily adapted for photo-induction of various light-responsive molecules.

Two-Photon-Based fotoativação no Live Embriões Zebrafish

Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic ...

Biologia

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 ...

Single Cell Fate Mapping in Zebrafish

The ability to differentially label single cells has important implications in developmental biology. For instance, determining how hematopoietic, lymphatic, and blood vessel lineages arise in developing embryos requires fate mapping and lineage tracing of undifferentiated precursor cells. Recently, photoactivatable proteins which include: Eos1, 2, PAmCherry3, Kaede4-7, pKindling8, and KikGR9, 10 have received wide interest as cell tracing probes. The fluorescence spectrum of these photosensitive proteins can be easily converted with UV excitation, allowing a population of cells to be distinguished from adjacent ones. However, the photoefficiency of the activated protein may limit long-term cell tracking11. As an alternative to photoactivatable proteins, caged fluorescein-dextran has been widely used in embryo model systems7, 12-14. Traditionally, to uncage fluorescein-dextran, UV excitation from a fluorescence lamp house or a single photon UV laser has been used; however, such sources limit the spatial resolution of photoactivation. Here we report a protocol to fate map, lineage trace, and detect single labeled cells. Single cells in embryos injected with caged fluorescein-dextran are photoactivated with near-infrared laser pulses produced from a titanium sapphire femtosecond laser. This laser is customary in all two-photon confocal microscopes such as the LSM 510 META NLO microscope used in this paper. Since biological tissue is transparent to near-infrared irradiation15, the laser pulses can be focused deep within the embryo without uncaging cells above or below the selected focal plane. Therefore, non-linear two-photon absorption is induced only at the geometric focus to uncage fluorescein-dextran in a single cell. To detect the cell containing uncaged fluorescein-dextran, we describe a simple immunohistochemistry protocol16 to rapidly visualize the activated cell. The activation and detection protocol presented in this paper is versatile and can be applied to any model system. 
Note: The reagents used in this protocol can be found in the table appended at the end of the article.

A method is described to photoactivate single cells containing a caged fluorescent protein using two-photon absorption from a Ti:Sapphire femtosecond laser oscillator. To fate map the photoactivated cell, immunohistochemistry is used. This technique can be applied to any cell type.

Mapeamento Destino única célula em Zebrafish

The ability to differentially label single cells has important implications in developmental biology. For instance, determining how hematopoietic, ...

Cell Tracking Using Photoconvertible Proteins During Zebrafish Development

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of genetically-encoded fluorescent proteins has proven a valuable strategy for elucidating dynamic morphogenetic processes as they occur in the intact organism. During the past decade, the development of photoactivatable and photoconvertible fluorescent proteins has opened the possibility to investigate the fate of discrete subpopulations of tagged proteins1. Unlike photoactivatable proteins, photoconvertible fluorescent proteins (PCFPs) are readily tracked and imaged in their native emission state prior to photoconversion, making it easier to identify and select regions by optical inspection. PCFPs, such as Kaede2, KikGR3, Dendra4 and EosFP5, can be shifted from green to red upon exposure to UV or blue light due to a His-Tyr-Gly tripeptide sequence which forms a green chromophore that can be photoconverted to a red one by a light-catalyzed &beta;-elimination and subsequent extension of a &pi;-conjugated system3. PCFPs and their monomeric variants are useful tools for tracking cells6-10 and studying protein dynamics11-14, respectively. During recent years, PCFPs have been expressed in different animal model, such as zebrafish6, chicken7,8 and mouse9,10 for cell fate tracking. Here we report a protocol for cell-specific photoconversion of PCFPs in the living zebrafish embryo and further tracking of photoconverted proteins at later developmental stages. This methodology allows studying, in a tissue-specific manner, cell biological events underlying morphogenesis in the zebrafish animal model.

Here, we present a method for the photoactivated switch of photoconvertible fluorescent proteins (PCFPs) in the living zebrafish embryo and further tracking of photoconverted protein at specific time points during development. This methodology allows monitoring of cell biological events underlying different developmental processes in a live vertebrate organism.

Rastreamento de celular utilizando proteínas Photoconvertible Durante o Desenvolvimento Zebrafish

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of ...