作者要感谢劳拉安妮洛厄谁开发这项技术在实验室中。 HS是由NIHMH70926支持。詹妮弗Gutzman支持CSBi /默克博士后。

协议第1部分：准备显微注射<ol><li>准备使用萨特仪器针拉马拉毛细管针注射。 </li><li>用荧光染料（如得克萨斯州红葡聚糖）填写针。 </li><li>芒针在显微和显微注射器具。 </li><li>切成适当大小的针的角度，创建一个斜角提示。 </li><li>测量液滴大小，并检查它每注入1 - 2nl之间的石油。 </li></ol>第2部分：准备胚胎<ol><li>注入30分钟，比利益阶段的早期胚胎。例如，要研究在受精后24小时（HPF）的心室，注入胚胎23.5 HPF。根据金梅尔等阶段的胚胎。 （4）。 </li><li>在立体显微镜下，从胚胎的使用镊子小心取出的绒毛。 </li><li>使用涂有1％的琼脂糖一个塑料盘，用塑料1-200微升枪头戳孔在琼脂糖。从孔，使用镊子小心取出琼脂糖插头。 </li><li>在胚胎媒体的胚胎转移到有孔的琼脂糖菜。 </li><li>添加tricaine（韦斯特（5）根据）向媒体麻醉的胚胎，并防止在实验过程中的运动。 </li><li>胚胎尾巴轻轻将入孔，和东方它使胚胎后注射器具。 </li></ol>第3部分：注射脑室<ol><li>要注入脑室，安排，使针尖在同一领域的高功率的胚胎的显微操作设置。 </li><li>没有击中下方的脑组织通过后脑后r0/r1 hingepoint薄roofplate小心翼翼地把针头。 </li><li>注入足够的染料完全填补心室。这可能需要几针，以填补心室的空间，取决于胚胎阶段。 </li></ol>第4部分：成像<ol><li>使用干净的1％琼脂糖涂层盘，在盘子里戳的新的漏洞，取出插头，并添加tricaine麻醉胚胎，防止运动。 </li><li>脑室注射胚胎的尾巴放入孔和一个背影像的位置。 </li><li>使用透射光拍摄图像。 </li><li>这是非常关键的不动的胚胎或显微镜。 </li><li>更改的设置，在显微镜图像，并采取荧光灯。 </li><li>重新定位的胚胎采取横向与透射光荧光灯图像。 </li><li>另存为TIFF文件在Photoshop图像处理的图像。 </li></ol>第5部分：图像处理<ol><li>要在Photoshop中处理图像，打开透射光荧光灯图像，并在同一位置上采取相同的胚胎。确保所有的设置都为每个图像相同。 </li><li>拖到您的荧光图像和透射光图像完全一致。 </li><li>随着荧光图像选择，选择“图像”，“调整”，然后在“替换颜色”，改变的黑色背景为白色。 </li><li>在“替换颜色”窗口中的“模糊性”因素调整的权利，直到荧光图像看起来颜色均匀一致。 </li><li>在“图层”窗口，选择“乘”，以查看叠加图像。脑室空间影像透射光图像完全匹配。 </li><li>任何其他图像保存这个文件，然后重复。 </li></ol>代表性的成果/成果正确的脑室注射图像显示在图1面板广告，例如不正确的注射图像显示在EH的。正确的注射有锋利的边缘和非弥漫性染料。不正确的注射，发生当针插入太远入脑室，点击下面的脑组织，可导致脑室空间的外部可见的染料和蛋黄。 <img src="/files/ftp_upload/1218/1218figure1.png" alt="图1" width="600" height="742" /> 图1。脑室注射25 HPF野生型胚胎 （AD）的正确的注射方法（EH）的不正确的注射方法作为例子所示。 （A，E）与相应的荧光图像背明图像（B，F）和荧光和明图像叠加显示正确和不正确的注射方法（C，G）。箭头指示染料已经超越了脑室空间，由于一个不正确的脑室注射（见“故障排除”）地区。眼前是所有图像左侧。 故障排除： <table border="1"><tbody><tr style="font-weight:bold; font-size:16px;"><td>问题</tD&gt; <td>原因</td><td>补救</td></tr><tr><td>您是挤压针的胚胎。 </td><td>你的针太钝或尖太大。 </td><td>开始一个新的针，不打破它早。锥您像一个注射器针头锋利的针。 </td></tr><tr><td>染料整个胚胎和蛋黄（见图1E - H）。 </td><td>通过组织您的针去，并没有停留在脑室空间。 </td><td>你的针头可能没有足够锋利，所以你无法控制穿刺的速度。 </td></tr><tr><td>这种染料是太微弱或没有前脑。 </td><td>您没有使用一个足够高的注射压力，或你的针是远远不够前到达前脑，当你注入染料。 </td><td>增加注射压力或放置针在注射前略多。如果需要更详细的是前脑的，你可以把针通过中脑，后脑边界。您也可以简单地等待染料位前成像进一步弥漫。 </td></tr><tr><td>您的荧光图像在Photoshop中的颜色替换后的边缘周围的黑暗。 </td><td>你忘了，改变“颜色替换”窗口中的“模糊性”设置。 </td><td>移动的“模糊性”的“颜色替换”窗口中的权利的方式。 </td></tr><tr><td>中针会不会穿刺后脑roofplate。 </td><td>你的针是不正确的削减。 </td><td>创建一个新的针。如果你是做了很多注射，您可能需要几针，因为他们可以得到沉闷。 </td></tr></tbody></table>

<ol>
	<li>Gutzman, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+the+zebrafish+midbrain-hindbrain+boundary+constriction+requires+laminin-dependent+basal+constriction.">Formation of the zebrafish midbrain-hindbrain boundary constriction requires laminin-dependent basal constriction.</a> Mech. Dev. 125, 974-983 (2008).</li><li>Lowery, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+and+Classification+of+Zebrafish+Brain+Morphology+Mutants.">Characterization and Classification of Zebrafish Brain Morphology Mutants.</a> Anat. Rec. (Hoboken). 292, 94-106 (2009).</li><li>Lowery, L. A., 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=Initial+formation+of+zebrafish+brain+ventricles+occurs+independently+of+circulation+and+requires+the+nagie+oko+and+snakehead/atp1a1a.1+gene+products.">Initial formation of zebrafish brain ventricles occurs independently of circulation and requires the nagie oko and snakehead/atp1a1a.1 gene products.</a> Development. 132, 2057-2067 (2005).</li><li>Kimmel, 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=Stages+of+embryonic+development+of+the+zebrafish.">Stages of embryonic development of the zebrafish.</a> Dev. Dyn. 203, 253-310 (1995).</li><li>Westerfield, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Zebrafish Book: A guide for the laboratory use of zebrafish. , (1995).</li></ol>

在这段视频中，我们演示了如何注入荧光染料（得克萨斯州红葡聚糖），斑马鱼脑室。这种方法是用来在脑室周围神经上皮空间可视化，并确定脑室空间的形状以及周围脑组织的形状是非常有用。它使我们能够更好地了解脑室形成，随着时间的推移活胚胎脑的形态发生过程。这项技术是一个极好的工具，为研究脑室形成缺陷和脑的形态发生突变体的初步鉴定和研究。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Forceps</td>
<td>Tool</td>
<td>Fine Science Tools</td>
<td>11252-20</td>
<td>&nbsp;</td>
<tr>
<td>Capillary Tubes (needles)</td>
<td>Tools</td>
<td>Frederick Haer and Co.</td>
<td>30-30-1</td>
<td>&nbsp;</td>
<tr>
<td>Agarose-Coated dishes</td>
<td>Tools</td>
<td>Agarose (Seakem GTG; Lonza) Dishes (Corning) </td>
<td>Agarose (50027) Dishes (430166) </td>
<td>Make agarose approximately 2-3 mm deep in the dish depending on the stage of embryo you are injecting</td>
</tr>
<tr>
<td>Dissecting Microscope</td>
<td>Microscope</td>
<td>Zeiss Stereomicroscope Stemi SV 6 </td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Microscope Camera with Fluorescence capabilities and with image capture software</td>
<td>Tools</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>1-200 &mu; pipette tips</td>
<td>Tools</td>
<td>Tip One, US Scientific</td>
<td>1111-0806</td>
<td>These are the perfect size to poke the holes in the agarose and have the embryos fit perfectly.</td>
</tr>
<tr>
<td>Photoshop</td>
<td>Image Analysis</td>
<td>Adobe</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Embryo Loop</td>
<td>Tools</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Make these yourself with a glass pipette and hair or fishing line and seal with beeswax.</td>
</tr>
<tr>
<td>Microinjector</td>
<td>Tools</td>
<td>Medical Systems Research Products Harvard Apparatus</td>
<td>PL1-100</td>
<td>&nbsp;</td>
<tr>
<td>Needle Puller</td>
<td>Tools</td>
<td>Sutter Instruments</td>
<td>&nbsp;</td>
<td>Settings (Heat 785, Pull 70, Velocity 40, Time 70).</td>
</tr>
<tr>
<td>Micromanipulator</td>
<td>Tools</td>
<td>Narishige</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Fluorescent dye Texas-Red Dextran 70,000MW</td>
<td>Reagent</td>
<td>Molecular Probes</td>
<td>D1830</td>
<td>Other Molecular weights are available if desired.</td>
</tr>
<tr>
<td>Tricaine (3-aminobenzoic acid ethyl ester)</td>
<td>Reagent</td>
<td>Sigma</td>
<td>A-5040</td>
<td>&nbsp;</td>
<tr>
<td>Embryo Media</td>
<td>Reagent</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>According to Westerfield (5)</td>
</tr>		</tbody>
		</table>
		</div>

zebrafish brain ventricle injection

正确的大脑心室形成胚胎大脑发育过程中是必需的正常的脑功能。脑室高度保守的大脑内充满脑脊液腔。在斑马鱼，神经管形成后，神经上皮经历了一系列的收缩和褶皱填充液体造成脑室形成。为了了解心室形成过程中，上皮形状的变化，在同一时间发生，我们需要一个方法来可视化脑组织相比，心室空间。然而，透明的斑马鱼胚胎的性质，使得它很难区分脑室空间组织。因此，我们制定了脑室注射技术脑室空间充满了一种荧光染料和明和荧光显微镜成像。明和荧光图像，然后处理，并在Photoshop中叠加。这种技术允许可视化与荧光染料心室的空间，比较明形象的神经上皮的形状。在斑马鱼的脑脑室注射可以采用18小时受精后通过早期的幼体阶段。我们已经广泛使用这种技术在脑室形成和形态发生的研究以及在脑的形态发生突变体（1-3）特征。

Watch this Scientific Journal Video about Zebrafish Brain Ventricle Injection at JoVE.com

Zebrafish Brain Ventricle Injection

神经管形成后，神经上皮收缩和皱褶而胚胎脑脊液（eCSF）形成的胚胎脑室管填充。我们开发这个脑室注射技术，以更好地可视化的充满液体的空间，相反，在一个活的胚胎神经上皮形状。

斑马鱼脑室注射液

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

Research

JoVE Journal

Biology

21.3K 次观看.  Whitehead Institute for Biochemical Research. 神经管形成后，神经上皮收缩和皱褶而胚胎脑脊液（eCSF）形成的胚胎脑室管填充。我们开发这个脑室注射技术，以更好地可视化的充满液体的空间，相反，在一个活的胚胎神经上皮形状。

视频: Zebrafish Brain Ventricle Injection

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.

现场共聚焦显微镜对斑马鱼的胚胎脑成像

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 ...

科研

生物学

Retro-orbital Injection in Adult Zebrafish

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

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

在成年斑马鱼的眼窝射出

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

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

Cells change extensively in their locations and property during embryogenesis. These changes are regulated by the interactions between the cells and their environment. Chimeric embryos, which are composed of cells of different genetic background, are great tools to study the cell-cell interactions mediated by genes of interest. The embryonic transparency of zebrafish at early developmental stages permits direct visualization of the morphogenesis of tissues and organs at the cellular level. Here, we demonstrate a protocol to generate chimeric retinas and brains in zebrafish embryos and to perform live imaging of the donor cells. The protocol covers the preparation of transplantation needles, the transplantation of GFP-expressing donor blastomeres to GFP-negative hosts, and the examination of donor cell behavior under live confocal microscopy. With slight modifications, this protocol can also be used to study the embryonic development of other tissues and organs in zebrafish. The advantages of using GFP to label donor cells are also discussed. 

We demonstrate a protocol to generate chimeric zebrafish embryos for live imaging cellular behavior during embryogenesis.

移植绿色荧光蛋白表达对视网膜和大脑发育的实时成像嵌合斑马鱼胚胎的卵裂球

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

Intraperitoneal Injection into Adult Zebrafish

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

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

腹腔注射到成年斑马鱼

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

Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development

In recent years, electroporation has become a popular technique for in vivo transfection of DNA, RNA, and morpholinos into various tissues, including the eye, brain, and somites of zebrafish. The advantage of electroporation over other methods of genetic manipulation is that specific tissues can be targeted, both spatially and temporally, for the introduction of macromolecules by the application of electrical current. Here we describe the use of electroporation for transfecting mif and mif-like morpholinos into the tissues of the developing inner ear of the zebrafish. In past studies, mif morpholino injected into embryos at the 1- to 8-cell stage resulted in widespread morphological changes in the nervous system and eye, as well as the ear. By targeting the tissues of the inner ear at later stages in development, we can determine the primary effects of MIF in the developing inner ear, as opposed to secondary effects that may result from the influence of other tissues. By using phalloidin and acetylated tubulin staining to study the morphology of neurons, neuronal processes, and hair cells associated with the posterior macula, we were able to assess the efficacy of electroporation as a method for targeted transfection in the zebrafish inner ear. The otic vesicles of 24hpf embryos were injected with morpholinos and electroporated and were then compared to embryos that had received no treatment or had been only injected or electroporated. Embryos that were injected and electroporated showed a decrease in hair cell numbers, decreased innervation by the statoacoustic ganglion (SAG) and fewer SAG neurons compared with control groups. Our results showed that direct delivery of morpholinos into otocysts at later stages avoids the non-specific nervous system and neural crest effects of morpholinos delivered at the 1-8 cell stage. It also allows examination of effects that are directed to the inner ear and not secondary effects on the ear from primary effects on the brain, neural crest or periotic mesenchyme.

A method to deliver morpholinos directly into the zebrafish otocyst at 24hpf has been developed. Using microinjection of morpholinos into the lumen of otic vesicle and electroporation to effect penetration, we were able to bypass the effect of morpholinos on the brain and obtain effects specific to the inner ear.

通过注射和电穿孔的斑马鱼Otocyst的MIF Morpholinos直接运抵影响内耳发展

In recent years, electroporation has become a popular technique for in vivo transfection of DNA, RNA, and morpholinos into various tissues, including the ...

In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina

Many devastating inherited eye diseases result in progressive and irreversible blindness because humans cannot regenerate dying or diseased retinal neurons. In contrast, the adult zebrafish retina possesses the robust ability to spontaneously regenerate any neuronal class that is lost in a variety of different retinal damage models, including retinal puncture, chemical ablation, concentrated high temperature, and intense light treatment 1-8. Our lab extensively characterized regeneration of photoreceptors following constant intense light treatment and inner retinal neurons after intravitreal ouabain injection 2, 5, 9. In all cases, resident M&uuml;ller glia re-enter the cell cycle to produce neuronal progenitors, which continue to proliferate and migrate to the proper retinal layer, where they differentiate into the deficient neurons. 
	We characterized five different stages during regeneration of the light-damaged retina that were highlighted by specific cellular responses. We identified several differentially expressed genes at each stage of retinal regeneration by mRNA microarray analysis 10. Many of these genes are also critical for ocular development. To test the role of each candidate gene/protein during retinal regeneration, we needed to develop a method to conditionally limit the expression of a candidate protein only at times during regeneration of the adult retina. 
	Morpholino oligos are widely used to study loss of function of specific proteins during the development of zebrafish, Xenopus, chick, mouse, and tumors in human xenografts 11-14. These modified oligos basepair with complementary RNA sequence to either block the splicing or translation of the target RNA. Morpholinos are stable in the cell and can eliminate or "knockdown" protein expression for three to five days 12. 
	Here, we describe a method to efficiently knockdown target protein expression in the adult zebrafish retina. This method employs lissamine-tagged antisense morpholinos that are injected into the vitreous of the adult zebrafish eye. Using electrode forceps, the morpholino is then electroporated into all the cell types of the dorsal and central retina. Lissamine provides the charge on the morpholino for electroporation and can be visualized to assess the presence of the morpholino in the retinal cells. 
	Conditional knockdown in the retina can be used to examine the role of specific proteins at different times during regeneration. Additionally, this approach can be used to study the role of specific proteins in the undamaged retina, in such processes as visual transduction and visual processing in second order neurons.

In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina

A method to conditionally knockdown a target protein&#x2019;s expression in the adult zebrafish retina is described, which involves intravitreally injecting antisense morpholinos and electroporating them into the retina. The resulting protein is knocked down for several days, which allows testing the protein&#x2019;s role in the regenerating or intact retina.

在体内电穿孔Morpholinos到成年斑马鱼视网膜

Many devastating inherited eye diseases result in progressive and irreversible blindness because humans cannot regenerate dying or diseased retinal ...

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

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

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

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

再生的成年斑马鱼尾鳍在吗啉代入体内电穿孔

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

Microgavage of Zebrafish Larvae

The zebrafish has emerged as a powerful model organism for studying intestinal development1-5, physiology6-11, disease12-16, and host-microbe interactions17-25. Experimental approaches for studying intestinal biology often require the in vivo introduction of selected materials into the lumen of the intestine. In the larval zebrafish model, this is typically accomplished by immersing fish in a solution of the selected material, or by injection through the abdominal wall. Using the immersion method, it is difficult to accurately monitor or control the route or timing of material delivery to the intestine. For this reason, immersion exposure can cause unintended toxicity and other effects on extraintestinal tissues, limiting the potential range of material amounts that can be delivered into the intestine. Also, the amount of material ingested during immersion exposure can vary significantly between individual larvae26. Although these problems are not encountered during direct injection through the abdominal wall, proper injection is difficult and causes tissue damage which could influence experimental results. We introduce a method for microgavage of zebrafish larvae. The goal of this method is to provide a safe, effective, and consistent way to deliver material directly to the lumen of the anterior intestine in larval zebrafish with controlled timing. Microgavage utilizes standard embryo microinjection and stereomicroscopy equipment common to most laboratories that perform zebrafish research. Once fish are properly positioned in methylcellulose, gavage can be performed quickly at a rate of approximately 7-10 fish/ min, and post-gavage survival approaches 100% depending on the gavaged material. We also show that microgavage can permit loading of the intestinal lumen with high concentrations of materials that are lethal to fish when exposed by immersion. To demonstrate the utility of this method, we present a fluorescent dextran microgavage assay that can be used to quantify transit from the intestinal lumen to extraintestinal spaces. This test can be used to verify proper execution of the microgavage procedure, and also provides a novel zebrafish assay to examine intestinal epithelial barrier integrity under different experimental conditions (e.g. genetic manipulation, drug treatment, or exposure to environmental factors). Furthermore, we show how gavage can be used to evaluate intestinal motility by gavaging fluorescent microspheres and monitoring their subsequent transit. Microgavage can be applied to deliver diverse materials such as live microorganisms, secreted microbial factors/toxins, pharmacological agents, and physiological probes. With these capabilities, the larval zebrafish microgavage method has the potential to enhance a broad range of research fields using the zebrafish model system.

We present a novel method for microgavage of larval zebrafish utilizing standard embryo microinjection and stereomicroscopy equipment. We demonstrate that microgavage is a safe and efficient technique useful for delivering controlled amounts of diverse materials specifically into the larval zebrafish intestinal lumen.

Microgavage斑马鱼幼虫

The zebrafish has emerged as a powerful model organism for studying intestinal development1-5, physiology6-11, disease12-16, and host-microbe ...

Reverse Genetic Morpholino Approach Using Cardiac Ventricular Injection to Transfect Multiple Difficult-to-target Tissues in the Zebrafish Larva

The zebrafish is an important model to understand the cell and molecular biology of organ and appendage regeneration. However, molecular strategies to employ reverse genetics have not yet been adequately developed to assess gene function in regeneration or tissue homeostasis during larval stages after zebrafish embryogenesis, and several tissues within the zebrafish larva are difficult to target. Intraventricular injections of gene-specific morpholinos offer an alternative method for the current inability to genomically target zebrafish genes in a temporally controlled manner at these stages. This method allows for complete dispersion and subsequent incorporation of the morpholino into various tissues throughout the body, including structures that were formerly impossible to reach such as those in the larval caudal fin, a structure often used to noninvasively research tissue regeneration. Several genes activated during larval finfold regeneration are also present in regenerating adult vertebrate tissues, so the larva is a useful model to understand regeneration in adults. This morpholino dispersion method allows for the quick and easy identification of genes required for the regeneration of larval tissues as well as other physiological phenomena regulating tissue homeostasis after embryogenesis. Therefore, this delivery method provides a currently needed strategy for temporal control to the evaluation of gene function after embryogenesis.&#160;

An adaptable reverse genetic method for zebrafish to assess gene function during later stages of development and physiological homeostasis such as tissue regeneration using intraventricular injections of gene-specific morpholinos.

反向遗传吗啉使用方法心脏心室射出转染多难靶组织中的斑马鱼幼虫

The zebrafish is an important model to understand the cell and molecular biology of organ and appendage regeneration. However, molecular strategies to ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

肾毒素显微注射斑马鱼到模型急性肾损伤

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...