Este estudo foi apoiado por um dos Institutos Nacionais de Saúde (NIH) Core Grant (5P30EY008098) e os fundos a seguir para XW: Grant NIH R01EY016099 e Pesquisa para prevenir a cegueira Prêmio de Desenvolvimento de Carreira. Agradecemos a Lathrop Kira de assistência em imagem confocal.

Dia 1. Preparação 1. Configurar atravessa peixes Configurar cruza pairwise de peixe-zebra da noite. Para evitar acasalamento ao acaso antes do tempo desejado, use divisórias para separar o peixe do sexo feminino e masculino nas cassetes de acasalamento. Expressando GFP-peixes transgénicos são usados ​​como fonte de blastômeros doador. A linhagem transgênica pt104 (Zou et al., 2008), usado aqui, expressa ubiquitously GFP sob o controle do promotor EF1. Expressão GFP permite a visualização de células do doador por imagem ao vivo. Outras linhas de peixes transgénicos que expressam proteínas fluorescentes adequado pode ser usado para necessidades específicas. 2. Prepare em forma de cunha agarose poços para a realização de embrião Despeje derretido agarose 1%, preparada em água do ovo E3 (Westerfield, 2007), em uma placa de Petri. Float um molde de plástico que tem saliências em forma de cunha na solução de agarose e deixar a solução de agarose completamente solidificar. Remover o molde com cuidado e coloque a cama agarose com água E3. 3. Prepare agulhas transplante Use um extrator de agulhas vertical (David KOPF Instruments) com potência 11,5 configuração para fazer agulhas, puxando pipetas de vidro capilar (Instrumento de precisão Mundial). Dicas agulha bom deve taper com eixos de comprimento. Moer as dicas agulha em um ângulo de 45 graus com uma Grinder Micro (Marishige) até aberturas chanfradas de 40-45μm de diâmetro interno são obtidos (Fig. 1A). Para limpar as pontas de agulhas, anexar uma mangueira até o fim brusco da agulha, conectar a mangueira a uma seringa, e então absorver e liberar uma solução de ácido fluorídrico 10% até que todo o entulho é removido. Em seguida, lave as pontas com água destilada, seguido pelo etanol 100%. Secar as agulhas até que todos evapora etanol. É importante assegurar que as pontas estão completamente secos: etanol residual vai arruinar as agulhas durante a etapa de polimento de alta temperatura. Para suavizar e polonês as arestas das pontas de agulha, coza as pontas da agulha com o calor gerado pelo filamento de uma Forger Micro (Marishige). Não deixe que as pontas de agulha toque o filamento durante o polimento. A quantidade de eletricidade passando através do filamento ea distância entre o filamento e as pontas da agulha pode ser ajustado para obtenção de condições de aquecimento desejada. A temperatura não deve ser muito alto: isto irá derreter e deformar as pontas da agulha. Após as arestas são suavizadas, cuidadosamente tocar o filamento aquecido com a ponta da agulha e puxe o filamento longe da agulha para gerar uma extremidade pontiaguda (Figura 1B). Uma agulha fina, lisa e limpa é fundamental para a obtenção de blastômeros doador intacta e para não danificar os embriões host. 4. Prepare uma sonda de embrião de posicionamento Puxe uma pipeta de vidro sobre uma chama de gás para obter uma sonda de vidro fino com uma extremidade smoothened. Esta sonda será usado para posicionar os embriões na orientação correta antes do transplante. Dia 2. Blastômero transplante 1. Coletar e embriões dechorionate No dia seguinte, retire os divisores com os cassetes de cruz para permitir que os peixes mate. Coloque os embriões em placas de Petri com água E3. Então, os embriões dechorionate manualmente arrancando o córions dos embriões com um par de fórceps bem. Use uma pipeta de vidro com haste inclinou-se para transferir cuidadosamente os embriões dechorionated em agarose poços. Evitar qualquer contato dos embriões com o ar, que causam os embriões para estourar. Deixe os embriões se desenvolvem em 28.5 ° C nos poços agarose até 3 horas após a fecundação, ou hpf. 2. Criar um aparelho de transplante Enquanto os embriões se desenvolvem, configurar um aparelho de transplante, ligando a agulha para o transplante mineral oil-filled sistema de micro-bombeamento. Certifique-se que o sistema não vaza e não bolhas de ar estão presos no sistema. Voltar preencher a agulha transplante inteiro com óleo mineral, com exceção do 0,5-1 mL de espaço na abertura da ponta. 3. Transplante de blastômeros Para transplante de blastômeros, use uma sonda de posicionamento de vidro para orientar o lado blastômero de embriões 3-4-hpf para cima. Então, gentilmente inserir a agulha em um transplante de embrião doador e, lentamente, sugar até 20/05 blastômeros na agulha. Inserir a agulha blastômero cheio em um embrião hospedeiro e solte o blastômeros lentamente. O local em que os blastômeros são liberados irá influenciar em sua progênie localizar em fases posteriores de desenvolvimento. Para analisar o desenvolvimento da retina e do cérebro, as células de liberação no pólo animal. Durante o transplante, certifique-se que a ponta da agulha não contato com o ar. Para minimizar danos mecânicos, embriões de acolhimento deve ser deixado nos poços agarose a 28,5 ° C até o dia seguinte. Então, tRANSFERÊNCIA os embriões mosaico para placas de 24 poços pré-revestidos com 0,5 ml de agarose 1%, com um embrião em cada poço. 1 ml de água do ovo E3 é adicionada a cada poço. Para evitar infecções bacterianas, adicione 10 ml de 100X penicilina e estreptomicina para a água de ovo E3. Dia 3. Incorporação e imagens ao vivo de embriões mosaico 1. Embriões incorporação Prepare 1,5% baixo ponto de fusão de agarose (LMP) em água de ovo E3 e manter a solução em banho-maria a 30 ° C. Transferência de um embrião de mosaico para um prato FluoroDish cultura de tecidos com um fundo de vidro de 0,17 milímetros de espessura (Instrumentos de Precisão Mundial). Retirar a água em excesso E3 para deixar o embrião apenas coberto por uma quantidade mínima de E3. Adicionar 30-50 LMP derretido mL de 1,5% para o embrião. Rapidamente a posição do olho ou o cérebro mais próximo possível do fundo de vidro quanto possível antes de a solução de agarose solidifica. Depois que a solução esfria, adicione a solução de agarose adicionais para proteger ainda mais os embriões no lugar. Em seguida, mergulhe a solidificou agarose bloco com 2-3 ml de água do ovo E3. 2. Imagem confocal Para microscopia confocal, um objetivo imersão em água invertido (Olympus, PlanApo, 40 X/0.90 WLSM, Japão) com uma profundidade grande foco é usado. Uma gota de água é adicionada para o objetivo e em seguida, coloque uma placa de cultura de tecidos FluoroDish no objectivo. Para o desenvolvimento da imagem, execute lapso de tempo de imagem por tirar fotos dos embriões a cada 5 minutos. Dependendo da natureza dos experimentos, os intervalos de tempo entre os disparos devem ser ajustados. Resultados representativos A figura 2 ilustra um representante 24 hpf zebrafish mosaico. Expressão GFP destaca as células do doador em verde. As células da retina neuroepiteliais abrangem toda a espessura da parede da retina. O filme mostra os movimentos de células do doador no cérebro anfitrião em 24 hpf. Morfologias células notificação de mudança ao longo do tempo. <img src="/files/ftp_upload/1924/1924fig1.jpg" alt="Figura 1" /> Figura 1. Formas das pontas de agulha transplante. A. A abertura chanfrada da ponta de uma agulha estava livre de detritos após lavagens ácido fluorídrico. B. A extremidade pontiaguda foi gerada na ponta da agulha. <img src="/files/ftp_upload/1924/1924fig2.jpg" alt="Figura 2" /> Figura 2. Visualização de GFP-expressando células do doador em uma embriões quiméricos zebrafish menos 24 hpf. O painel esquerdo mostra os sinais de GFP no cérebro e retina. O painel do meio é uma imagem de campo claro do embrião. O painel da direita mostra a imagem mesclada. Filme 1. Vivo de imagem de células do doador GFP positivos demonstraram a grandes mudanças na morfologia do cérebro de células gliais durante o desenvolvimento. Os quadros individuais do filme foram coletados a cada 5 minutos entre 24 e 25 hpf. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/1924/1924_Wei_Movie1.wmv">Clique aqui para ver o filme</a> .

<ol>
	<li>Zou, J., Lathrop, K., Sun, M., Wei, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intact+RPE+maintained+by+Nok+is+essential+for+retinal+epithelial+polarity+and+cellular+patterning+in+zebrafish.">Intact RPE maintained by Nok is essential for retinal epithelial polarity and cellular patterning in zebrafish.</a> Journal of Neuroscience. 28 (50), 13684-13695 (2008).</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+guide+for+the+laboratory+use+of+zebrafish+(Danio+rerio).">A guide for the laboratory use of zebrafish (Danio rerio).</a> THE ZEBRAFISH BOOK. , (2007).</li><li>Ho, R. K., Kane, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-autonomous+action+of+zebrafish+spt-1+mutation+in+specific+mesodermal+precursors.">Cell-autonomous action of zebrafish spt-1 mutation in specific mesodermal precursors.</a> Nature. 348, 728-730 (1990).</li><li>Catalano, A., Raymond, P., Goldman, D., Wei, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zebrafish+dou+yan+Mutation+Causes+Patterning+Defects+and+Extensive+Cell+Death+in+the+Retina.">Zebrafish dou yan Mutation Causes Patterning Defects and Extensive Cell Death in the Retina.</a> Developmental Dynamics. 236 (5), 1295-1236 (2007).</li></ol>

Neste vídeo, demonstramos um método para blastômero transplante para analisar o desenvolvimento da retina e do cérebro em zebrafish. Este protocolo também pode ser usado para analisar o desenvolvimento de outros tecidos e órgãos, simplesmente liberando a blastômeros de doadores para os locais correspondentes nos embriões host. A rotulagem com as moléculas de GFP rende um aspirador de fundo do que a marcação com corante fluorescente conjugada Dextran (Ho e Kane, 1990). Isto é porque os restos de tintas Dextran a partir de células de doadores mortos dura muito mais tempo do que GFP, inferindo com imagem (Catalano et al., 2007). Além disso, a GFP positivas células do doador são mais saudáveis ​​do que aqueles que contenham corantes Dextran.

E3 água ovo: <ul><li> 5 mM NaCl </li><li> 0,17 mM KCl </li><li> 0,33 mM CaCl 2 </li><li> 0,33 mM MgSO 4 </li><li> Azul de metileno 0,1% </li></ul>

transplantation of gfp-expressing blastomeres for live imaging of retinal and brain development in chimeric zebrafish embryos

Células mudam extensivamente em seus locais e dos bens durante a embriogênese. Essas alterações são reguladas pelas interações entre as células e seu meio ambiente. Embriões quiméricos, que são compostas de células de fundo genético diferente, são ótimas ferramentas para estudar as interações célula-célula mediada por genes de interesse. A transparência embrionário de zebrafish em fases iniciais de desenvolvimento permite a visualização direta da morfogênese de tecidos e órgãos em nível celular. Aqui, nós demonstramos um protocolo para gerar retinas quimérico e cérebros em embriões de peixe-zebra e para realizar imagens ao vivo das células do doador. O protocolo abrange a preparação de agulhas transplante, o transplante de GFP-expressando blastômeros doadores para GFP-negativos hosts, eo exame do comportamento dos doadores de células sob microscopia confocal ao vivo. Com pequenas modificações, este protocolo também pode ser usado para estudar o desenvolvimento embrionário de outros tecidos e órgãos em peixes-zebra. As vantagens de usar a GFP para as células do doador rótulo também são discutidos.

Watch this Scientific Journal Video about Transplantation of GFP-expressing Blastomeres for Live Imaging of Retinal and Brain Development in Chimeric Zebrafish Embryos at JoVE.com

Transplantation of GFP-expressing Blastomeres for Live Imaging of Retinal and Brain Development in Chimeric Zebrafish Embryos

Demonstramos um protocolo para gerar embriões quiméricos zebrafish para o comportamento imagens ao vivo do celular durante a embriogênese.

Transplante de GFP-expressando Blastômeros for Imaging ao vivo de Desenvolvimento da retina e do cérebro em embriões Zebrafish Quimérico

Cells change extensively in their locations and property during embryogenesis. These changes are regulated by the interactions between the cells and their ...

transplantation-gfp-expressing-blastomeres-for-live-imaging-retinal

Nanyang Technological University

Research

JoVE Journal

Biology

10.6K visualizações.  University of Pittsburgh. Demonstramos um protocolo para gerar embriões quiméricos zebrafish para o comportamento imagens ao vivo do celular durante a embriogênese.

Vídeo: Transplantation of GFP-expressing Blastomeres for Live Imaging of Retinal and Brain Development in Chimeric Zebrafish Embryos

Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual branches of peripheral sensory axons in zebrafish using the focused power of a femtosecond laser mounted on a two-photon microscope. The parameters for successful two-photon axotomy must be optimized for each microscope. We will demonstrate two-photon axotomy on both a custom built two-photon microscope and a Zeiss 510 confocal/two-photon to provide two examples.

Zebrafish trigeminal sensory neurons can be visualized in a transgenic line expressing GFP driven by a sensory neuron specific promoter 1. We have adapted this zebrafish trigeminal model to directly observe sensory axon regeneration in living zebrafish embryos. Embryos are anesthetized with tricaine and positioned within a drop of agarose as it solidifies. Immobilized embryos are sealed within an imaging chamber filled with phenylthiourea (PTU) Ringers. We have found that embryos can be continuously imaged in these chambers for 12-48 hours. A single confocal image is then captured to determine the desired site of axotomy. The region of interest is located on the two-photon microscope by imaging the sensory axons under low, non-damaging power. After zooming in on the desired site of axotomy, the power is increased and a single scan of that defined region is sufficient to sever the axon. Multiple location time-lapse imaging is then set up on a confocal microscope to directly observe axonal recovery from injury.

Here we describe a method for mounting zebrafish embryos for long-term imaging, two-photon imaging and tissue-damage techniques, and time-lapse confocal imaging.

Dois fótons axotomia e lapso de tempo de imagem confocal em embriões de peixe-zebra ao vivo

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo.  ...

Biologia

Live Imaging of the Zebrafish Embryonic Brain by Confocal Microscopy

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

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

Vivem de imagem do cérebro Zebrafish embrionárias por microscopia confocal

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

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 ...

Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily accessible at all stages of development. Moreover, their optical clarity allows high resolution imaging of cell and molecular dynamics in the natural environment of the intact embryo. We are using a live imaging approach to analyze cell behaviors during neural crest cell migration and the outgrowth and guidance of neuronal axons.
Live imaging is particularly useful for understanding mechanisms that regulate cell motility processes. To visualize details of cell motility, such as protrusive activity and molecular dynamics, it is advantageous to label individual cells. In zebrafish, plasmid DNA injection yields a transient mosaic expression pattern and offers distinct benefits over other cell labeling methods. For example, transgenic lines often label entire cell populations and thus may obscure visualization of the fine protrusions (or changes in molecular distribution) in a single cell. In addition, injection of DNA at the one-cell stage is less invasive and more precise than dye injections at later stages.
Here we describe a method for labeling individual developing neurons or neural crest cells and imaging their behavior in vivo. We inject plasmid DNA into 1-cell stage embryos, which results in mosaic transgene expression. The vectors contain cell-specific promoters that drive expression of a gene of interest in a subset of sensory neurons or neural crest cells. We provide examples of cells labeled with membrane targeted GFP or with a biosensor probe that allows visualization of F-actin in living cells1.
Erica Andersen, Namrata Asuri, and Matthew Clay contributed equally to this work.

This protocol describes imaging of individual neurons or neural crest cells in living zebrafish embryos. This method is used to examine cellular behaviors and actin localization using fluorescence confocal time-lapse microscopy.

Imagens ao vivo da motilidade celular e citoesqueleto de actina de neurônios individuais e células da crista neural em embriões Zebrafish

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily ...

Development of automated imaging and analysis for zebrafish chemical screens. 

We demonstrate the application of image-based high-content screening (HCS) methodology to identify small molecules that can modulate the FGF/RAS/MAPK pathway in zebrafish embryos. The zebrafish embryo is an ideal system for in vivo high-content chemical screens. The 1-day old embryo is approximately 1mm in diameter and can be easily arrayed into 96-well plates, a standard format for high throughput screening. During the first day of development, embryos are transparent with most of the major organs present, thus enabling visualization of tissue formation during embryogenesis. The complete automation of zebrafish chemical screens is still a challenge, however, particularly in the development of automated image acquisition and analysis. We previously generated a transgenic reporter line that expresses green fluorescent protein (GFP) under the control of FGF activity and demonstrated their utility in chemical screens 1. To establish methodology for high throughput whole organism screens, we developed a system for automated imaging and analysis of zebrafish embryos at 24-48 hours post fertilization (hpf) in 96-well plates 2. In this video we highlight the procedures for arraying transgenic embryos into multiwell plates at 24hpf and the addition of a small molecule (BCI) that hyperactivates FGF signaling 3. The plates are incubated for 6 hours followed by the addition of tricaine to anesthetize larvae prior to automated imaging on a Molecular Devices ImageXpress Ultra laser scanning confocal HCS reader. Images are processed by Definiens Developer software using a Cognition Network Technology algorithm that we developed to detect and quantify expression of GFP in the heads of transgenic embryos. In this example we highlight the ability of the algorithm to measure dose-dependent effects of BCI on GFP reporter gene expression in treated embryos.

Development of automated imaging and analysis for zebrafish chemical screens.

We report the development of a system for automated imaging and analysis of zebrafish transgenic embryos in multiwell plates. This demonstrates the ability to measure dose dependent effects of a small molecule, BCI, on Fibroblast Growth Factor reporter gene expression and provide technology for establishing high-throughput zebrafish chemical screens.

Desenvolvimento de imagem automatizada e análise química para as telas de zebrafish.

We demonstrate the application of image-based high-content screening (HCS) methodology to identify small molecules that can modulate the FGF/RAS/MAPK ...

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 ...

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 ...

Imaging Glycans in Zebrafish Embryos by Metabolic Labeling and Bioorthogonal Click Chemistry

Imaging glycans in vivo has recently been enabled using a bioorthogonal chemical reporter strategy by treating cells or organisms with azide- or alkyne-tagged monosaccharides1, 2. The modified monosaccharides, processed by the glycan biosynthetic machinery, are incorporated into cell surface glycoconjugates. The bioorthogonal azide or alkyne tags then allow covalent conjugation with fluorescent probes for visualization, or with affinity probes for enrichment and glycoproteomic analysis. This protocol describes the procedures typically used for noninvasive imaging of fucosylated glycans in zebrafish embryos, including: 1) microinjection of one-cell stage embryos with GDP-5-alkynylfucose (GDP-FucAl), 2) labeling fucosylated glycans in the enveloping layer of zebrafish embryos with azide-conjugated fluorophores via biocompatible Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), and 3) imaging by confocal microscopy3. The method described here can be readily extended to visualize other classes of glycans, e.g. glycans containing sialic acid4 and N-acetylgalactosamine5, 6, in developing zebrafish and in other living organisms.

A click-chemistry based method that allows for the rapid, noninvasive, and robust labeling of alkyne-tagged glycans in zebrafish embryos is described. Fucosylated glycans in the enveloping layer of zebrafish embryos in the late gastrulation stage were imaged in this study.

Glicanos imagem em embriões Zebrafish por Labeling Metabólica e Química Clique Bioorthogonal

Imaging glycans in vivo has recently been enabled using a bioorthogonal chemical reporter strategy by treating cells or organisms with azide- or ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

Imagens ao vivo de Apuramento celular por apoptose durante<em&gt; Drosophila</em&gt; Embriogênese

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

Analysis of Oxidative Stress in Zebrafish Embryos

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes oxidation of molecules (lipid, DNA, protein) and leads to cell death. Oxidative stress also impacts the progression of several pathological conditions such as diabetes, retinopathies, neurodegeneration, and cancer. Thus, it is important to define tools to investigate oxidative stress conditions not only at the level of single cells but also in the context of whole organisms. Here, we consider the zebrafish embryo as a useful in vivo system to perform such studies and present a protocol to measure in vivo oxidative stress. Taking advantage of fluorescent ROS probes and zebrafish transgenic fluorescent lines, we develop two different methods to measure oxidative stress in vivo: i) a &#8220;whole embryo ROS-detection method&#8221; for qualitative measurement of oxidative stress and ii) a &#8220;single-cell&#160;ROS detection method&#8221; for quantitative measurements of oxidative stress. Herein, we demonstrate the efficacy of these procedures by increasing oxidative stress in tissues by oxidant agents and physiological or genetic methods. This protocol is amenable for forward genetic screens and it will help address cause-effect relationships of ROS in animal models of oxidative stress-related pathologies such as neurological disorders and cancer.

Here we report a protocol to measure oxidative stress in living zebrafish embryos. This procedure allows reactive oxygen species (ROS) detection in both whole embryo tissues and single-cell populations. This protocol will accomplish both qualitative and quantitative analyses.

Transplante de GFP-expressando Blastômeros for Imaging ao vivo de Desenvolvimento da retina e do cérebro em embriões Zebrafish Quimérico

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