We thank Monika Kilchenmann, Federica Bisignani and Agathe Duda for their excellent technical assistance.

所有实验坚持以声明的动物眼科及研究协会在视觉视觉研究与眼科（ARVO）使用。 1，动物<ol><li>维持公司（俄勒冈州）水标准条件下6-12个月之间以26.5℃的温度和14/10小时的光/暗周期15株野生型斑马鱼（ 斑马鱼 ）。 </li><li>按照参与机构的审批由州兽医局后，经动物实验动物照护指引。 </li></ol> 2，MNU处理<ol><li>制备含有氮甲基 -N- -nitrosourea（MNU）150毫克/升干燥物质的水。注意！ MNU是有毒的;可能会导致癌症，遗传性的损害或伤害胎儿。 </li><li>孵育斑马鱼中含有MNU，在室温下60分钟的水。 </li><li>迅速用清水冲洗斑马鱼淡水把鱼到一个新的鱼缸没有MNU。维持标准的条件，只要所需的实验下的鱼。 </li></ol> 3，视力测量<ol><li>启动optomotor系统，从菜单中选择“测试”，并设置选项，以“简单楼梯”，“视力（频率）”和“随机/独立”16。 </li><li>安装的输液瓶填充500ml水约1μm的optomotor系统之上。 </li><li>将一个斑马鱼在考试室，并把它连接到输液瓶。放置在optomotor系统的检查室。 </li><li>开始测量和观察计算机屏幕上实时眼球运动。因此，积极响应（“是”）被定义为连续扫视了正确的方向，而一个否定的答复（“无”）代表随机眼球运动相似，与那些观测站进制光栅。如果斑马鱼表现出的眼里三个或更多的后续视动反应（OKR），按“是”;如果没有，请按“不”。 </li><li>提取的视力，其中已计算由软件通过确定视动刺激的空间频率的阈值时，根据菜单中的“结果”。 </li></ol> 4，组织学<ol><li>由乙基3 - 氨基苯甲酸酯（200-300毫克/升）的过量安乐死斑马鱼和去核的眼睛。 </li><li>在4℃下12小时固定整个眼睛用4％多聚甲醛（PFA）在磷酸盐缓冲盐水（PBS）中，然后脱水的样品在梯度醇系列。 </li><li>嵌入样品中石蜡，切5微米的部分通过视神经乳头（ONH）和它们安装在载玻片上。 </li><li>染色deparaffized石蜡切片用hemalum为4分钟，浸在幻灯片两次蒸馏水中后0.2％的盐酸ACID和0.8％的氨。染色用曙红的部分自来水中发展hemalum染色至少10分钟（H＆E）后3分钟。 </li><li>嵌入在安装介质中的脱水幻灯片，观察光镜下的幻灯片。 </li></ol> 5，免疫组化<ol><li>末端脱氧核苷酸转移酶缺口末端标记法（TUNEL） <ol><li>孵育20微克/毫升的蛋白酶K的去石蜡切片在室温下搅拌15分钟。用Tris洗部分三次，每次5分钟缓冲盐水（TBS）。 </li><li>孵化用50μlTUNEL反应混合物（10％标记溶液和90％的酶溶液）的部分，在湿润室中于37℃进行60分钟。用TBS，每次5分钟洗涤3次。 </li><li>安装带安装含有DAPI介质的幻灯片，并观察在荧光显微镜下的滑动。 </li></ol></li><li>增殖细胞核抗原（PCNA）染色<ol><li>沸腾在抗原修复缓冲液（Tris-EDTA + 0.05％吐温20，pH9.0）中的脱石蜡切片3分钟，洗三次，用TBS，每次5分钟。用100μl封闭溶液（TBS +10％山羊正常血清+1％牛血清白蛋白，pH7.6）中，在室温下搅拌1小时阻断。 </li><li>用在1抗PCNA的初级抗体染色1:200稀释，在湿润室中于4℃下过夜。用TBS +吐温20，每次5分钟洗涤3次。 </li><li>完成检测与在1相应的二级抗体1:500稀释，在室温下搅拌1小时。 </li><li>安装带安装含有DAPI介质的幻灯片，并观察在荧光显微镜下的滑动。 </li></ol></li></ol>

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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+zebrafish+as+a+model+for+complex+tissue+regeneration.">The zebrafish as a model for complex tissue regeneration.</a> Trends Genet. 29 (11), 611-620 (2013).</li><li>Brockerhoff, S. E., Fadool, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetics+of+photoreceptor+degeneration+and+regeneration+in+zebrafish.">Genetics of photoreceptor degeneration and regeneration in zebrafish.</a> Cell Mol. Life Sci. 68, 651-659 (2011).</li><li>Brand, M., Granato, M., N&#252;sslein-Volhard, C., N&#252;sslein-Volhard, C., Dahm, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Keeping+and+raising+zebrafish.">Keeping and raising zebrafish.</a> Zebrafish: A Practical Approach. , 7-38 (2002).</li><li>Tappeiner, C., Gerber, S., Enzmann, V., Balmer, J., Jazwinska, A., Tschopp, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual+acuity+and+contrast+sensitivity+of+adult+zebrafish.">Visual acuity and contrast sensitivity of adult zebrafish.</a> Front. Zool. 9 (1), 10 (2012).</li><li>Bailey, T. J., Fossum, S. L., Fimbel, S. M., Montgomery, J. E., Hyde, D. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+quantification+of+adult+and+developing+mouse+spatial+vision+using+a+virtual+optomotor+system.">Rapid quantification of adult and developing mouse spatial vision using a virtual optomotor system.</a> Invest. Ophthalmol Vis. Sci. 45 (12), 4611-4616 (2004).</li><li>Beck, J. C., Gilland, E., Tank, D. W., Baker, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+the+ontogeny+of+optokinetic+and+vestibulo-ocular+behaviors+in+zebrafish,+medaka,+and+goldfish.">Quantifying the ontogeny of optokinetic and vestibulo-ocular behaviors in zebrafish, medaka, and goldfish.</a> J. Neurophysiol. 92 (6), 3546-3561 (2004).</li><li>Fimbel, S. M., Montgomery, J. E., Burket, C. T., Hyde, D. 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The authors have nothing to disclose.

此前，本集团已转移光感受器变性的MNU模式从啮齿动物到斑马鱼系统9。随后的事件进行了描述，并随访了30天。在这段时间内完整视网膜形态退化和再生的初始治疗后发生。首先，组织学显示，从3天减少杆细胞计数与最小的相应8天，TUNEL染色MNU处理后第3天确定的视杆细胞的凋亡。再生开始的INL为3天，最长为5天外核层，增殖细胞可观察到的观察期，最大的结尾处5天，这是与此相反的INL在...

视觉是最重要的意义的人及其损害具有较高的社会经济影响。在发达国家，视网膜变性疾病是视力减退和失明的老年人中1的主要原因。最退行性视网膜疾病的原因只是部分了解和治疗方案，以夺回失去的视力是非常有限的。视网膜色素变性是视网膜变性疾病的原发性感光损失2-3。n的典型例子甲基 -N -nitrosourea（MNU）诱导的视网膜变性，因此被广泛应用在啮齿类动物模型与主光感受器细胞死亡4疾病。它是一种烷化剂，并导致良性和恶性肿瘤，通常会出现曝光5-7后几个月。此外，它会导致短期的观察期间内特定光感受器细胞死亡。由此，视网膜层structu的损失重和显著视网膜变薄了以浓度依赖性方式观察到。视网膜神经胶质细胞被激活，但在视网膜色素上皮细胞（RPE）没有变化被发现。内质网（ER）应激相关的细胞凋亡似乎是MNU作用的主要途径在视网膜8。 我们最近推出的MNU作为一种化学模型诱导光感受器变性斑马鱼9。除了 ​​其他原因，斑马鱼（ 斑马鱼 ）已成为因为它的视觉系统对其他脊椎动物10的相似之处在视觉研究很重要。外层视网膜包含感光体，它可被分成四个不同的锥面类型具有峰值灵敏度的紫外线，短，中等，和可见光谱的长波长和一个视杆型。在内核层（INL）的双极性，水平和无长突的interneurons细胞体被发现，如WELl与穆勒胶质细胞的胞体。在所述外丛状层（OPL）的光感受器和视网膜内层之间的突触联系形成的，而最接近透镜的细胞层是神经节细胞层（GC），该组件形成长轴突包括视神经和视束。神经节细胞和细胞中的内核层之间的突触联系形成于内网层（IPL）11。视网膜色素上皮所在的视网膜神经上皮层外，并围绕光感受器外段长微绒毛顶端12。此外，斑马鱼是高度再生，并能够再生毁损脑，视网膜，脊髓，心脏和其他组织13。当视网膜损伤时，细胞中的INL，这被认为是Müller细胞，被激活并具有分化成多种视网膜细胞类型的潜力。此外，它们还产生棒祖细胞，它们分别位于外核层。另一个让urce供给成年斑马鱼视网膜有新生细胞的纤毛边缘区。这个源是需要实现的视杆细胞的恒定密度的不断增长的斑马鱼眼14。 在MNU模型可以用作视网膜组织的简单和可再现的变性/再生方法。由于在斑马鱼中的生物过程的某些相似性和在人体中，这可能打开门，以确定参与细胞死亡途径，筛选潜在的神经保护药物。根据我们组先前的研究，我们现在说明这MNU诱导斑马鱼视网膜脱离和随之而来的再生包括根据实验室影片9功能变化模型的方法。

<table border="0" cellpadding="0" cellspacing="0" >
	<tbody>
		<tr >
			<td >Acetic acid</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>A6283</td>
			<td></td>
		</tr>
		<tr >
			<td >Ammonia</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>294993</td>
			<td>0.80%</td>
		</tr>
		<tr >
			<td >Bovine serum albumine (BSA)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>05470</td>
			<td></td>
		</tr>
		<tr >
			<td >Dako Pen</td>
			<td>Dako, Glostrup, Danmark</td>
			<td>S2002</td>
			<td></td>
		</tr>
		<tr >
			<td >DAPI mounting medium</td>
			<td>Vector Labs, Burlingame, CA, USA</td>
			<td>H-1200</td>
			<td></td>
		</tr>
		<tr >
			<td >Eosin</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>45260</td>
			<td></td>
		</tr>
		<tr >
			<td >Ethanol</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>2860</td>
			<td>100%, 96%, 70%</td>
		</tr>
		<tr >
			<td >Ethylenediaminetetraacetic acid (EDTA)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>ED</td>
			<td></td>
		</tr>
		<tr >
			<td >Ethyl 3-aminobenzoate methanesulfonate salt</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>E10521</td>
			<td>Tricaine</td>
		</tr>
		<tr >
			<td >Eukitt</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>3989</td>
			<td></td>
		</tr>
		<tr >
			<td >Goat anti-rabbit Alexa 594</td>
			<td>Life Technologies, Zug, Switzerland</td>
			<td>A11012</td>
			<td></td>
		</tr>
		<tr >
			<td >Goat normal serum</td>
			<td>Dako, Glostrup, Danmark</td>
			<td>X0907</td>
			<td></td>
		</tr>
		<tr >
			<td >Hydrochloric acid</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>320331</td>
			<td>0.20%</td>
		</tr>
		<tr >
			<td >In situ Cell Death Detection Kit</td>
			<td>Roche Applied Sciences, Rotkreuz, Switzerland</td>
			<td>11684795910</td>
			<td>TUNEL Kit</td>
		</tr>
		<tr >
			<td >Mayer&#39;s hemalum solution</td>
			<td>Merck, Darmstadt, Germany</td>
			<td>109249</td>
			<td></td>
		</tr>
		<tr >
			<td >Methylnitrosourea (MNU)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>N4766</td>
			<td>Toxic</td>
		</tr>
		<tr >
			<td >OptoMotry</td>
			<td>CerebralMechanics, Lethbridge, AB, Canada</td>
			<td>n.a.</td>
			<td></td>
		</tr>
		<tr >
			<td >Paraformaldehyde (PFA)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr >
			<td >Phosphate buffered saline (PBS)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>P5368</td>
			<td></td>
		</tr>
		<tr >
			<td >Proteinase K</td>
			<td>Dako, Glostrup, Danmark</td>
			<td>S3004</td>
			<td></td>
		</tr>
		<tr >
			<td >Rabbit anti-PCNA</td>
			<td>Santa Cruz Biotechnology, Santa Cruz, USA</td>
			<td>sc-33756</td>
			<td></td>
		</tr>
		<tr >
			<td >Superfrost Plus glass slides</td>
			<td>Gehard Menzel GmbH, Braunschweig, Germany</td>
			<td>10149870</td>
			<td></td>
		</tr>
		<tr >
			<td >Tris buffered saline (TBS)</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>P5912</td>
			<td></td>
		</tr>
		<tr >
			<td >Trizma&#210; base</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>T1503</td>
			<td></td>
		</tr>
		<tr >
			<td >Tween 20</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>P1379</td>
			<td></td>
		</tr>
		<tr >
			<td >Xylene</td>
			<td>Sigma-Aldrich, Buchs, Switzerland</td>
			<td>534056</td>
			<td></td>
		</tr>
		<tr >
			<td >Zebrafish (Danio rerio) AB (Oregon) strain</td>
			<td>University of Fribourg, Dept. of Biology</td>
			<td>n.a.</td>
			<td>Own fish facility</td>
		</tr>
	</tbody>
</table>

methylnitrosourea (mnu)-induced retinal degeneration and regeneration in the zebrafish: histological and functional characteristics

视网膜退行性疾病， 如视网膜色素变性，用得到的，为广大视力下降，在工业领域感光伤害帐户。动物模型是至关重要的意义，研究这种疾病。在这方面，在感光体特异性毒素N-甲基-N- -nitrosourea（MNU）已被广泛用于在啮齿动物药理学诱导的视网膜变性。此前，我们已经建立了MNU诱导的视网膜变性模型中的斑马鱼，在视觉研究的另一种流行的模型系统。 一个迷人的区别是哺乳动物在成年斑马鱼视网膜损伤后的再生持续神经。为了量化这一观察，我们在成年斑马鱼使用视力的测量。由此，视动反射被用于跟随在非麻醉的鱼的功能变化。这补充了组织学以及免疫staini吴凋亡（TUNEL）和增殖（PCNA）关联的发展形态变化。 综上所述，光感受器细胞凋亡MNU治疗，随后是细胞中的外核层（ONL）的显着降低三天之后出现。此后，将细胞在内核层（INL）和ONL的增殖被观察。在此，我们表明，不仅是一个完整的组织，而且功能性再生发生在30天的时间过程。现在我们说明的方法来量化和跟进的视频格式使用的MNU斑马鱼视网膜脱离和再生。

视力： 该实验装置[空间频率：0.042圆/度（C / D）;对比度：100％;漂移速度：20度/秒（D / SRC）;背光亮度：本研究的152 cd /米2]启用成年斑马鱼OKR评估。 VA测量的平均持续时间大约为5 - 10分钟，每一个斑马鱼，其耐受性的方法好。 MNU曝光前视力为0.577±0.014周/度（C / D）， 图1示出了视觉灵敏度当然150毫克/升的MNU后应用。从第1天开始，将测量结果显示在视敏?...

Watch this Scientific Journal Video about Methylnitrosourea MNU-induced Retinal Degeneration and Regeneration in the Zebrafish: Histological and Functional Characteristics at JoVE.com

Methylnitrosourea MNU-induced Retinal Degeneration and Regeneration in the Zebrafish: Histological and Functional Characteristics

在这里我们展示视网膜脱离和再生，对以N甲基 -N- -nitrosourea在成年斑马鱼的视觉功能的影响进行量化。其次是在内核层扩散视力丧失和降低光感受器号。发生完整的形态和功能恢复的初步治疗后30天。

Methylnitrosourea（MNU）诱导的视网膜变性和再生的斑马鱼：组织学和功能特征

Retinal degenerative diseases, e.g. retinitis pigmentosa, with resulting photoreceptor damage account for the majority of vision loss in the industrial ...

methylnitrosourea-mnu-induced-retinal-degeneration-regeneration

Research

JoVE Journal

Biology

Methylnitrosourea (MNU)-induced Retinal Degeneration and Regeneration in the Zebrafish: Histological and Functional Characteristics

11.4K 次观看.  University of Bern. 在这里我们展示视网膜脱离和再生，对以N甲基 -N- -nitrosourea在成年斑马鱼的视觉功能的影响进行量化。其次是在内核层扩散视力丧失和降低光感受器号。发生完整的形态和功能恢复的初步治疗后30天。 

视频: Methylnitrosourea MNU-induced Retinal Degeneration and Regeneration in the Zebrafish: Histological and Functional Characteristics

Laser Ablation of the Zebrafish Pronephros to Study Renal Epithelial Regeneration

Acute kidney injury (AKI) is characterized by high mortality rates from deterioration of renal function over a period of hours or days that culminates in renal failure1. AKI can be caused by a number of factors including ischemia, drug-based toxicity, or obstructive injury1. This results in an inability to maintain fluid and electrolyte homeostasis. While AKI has been observed for decades, effective clinical therapies have yet to be developed. Intriguingly, some patients with AKI recover renal functions over time, a mysterious phenomenon that has been only rudimentally characterized1,2. Research using mammalian models of AKI has shown that ischemic or nephrotoxin-injured kidneys experience epithelial cell death in nephron tubules1,2, the functional units of the kidney that are made up of a series of specialized regions (segments) of epithelial cell types3. Within nephrons, epithelial cell death is highest in proximal tubule cells. There is evidence that suggests cell destruction is followed by dedifferentiation, proliferation, and migration of surrounding epithelial cells, which can regenerate the nephron entirely1,2. However, there are many unanswered questions about the mechanisms of renal epithelial regeneration, ranging from the signals that modulate these events to reasons for the wide variation of abilities among humans to regenerate injured kidneys.
The larval zebrafish provides an excellent model to study kidney epithelial regeneration as its pronephric kidney is comprised of nephrons that are conserved with higher vertebrates including mammals4,5. The nephrons of zebrafish larvae can be visualized with fluorescence techniques because of the relative transparency of the young zebrafish6. This provides a unique opportunity to image cell and molecular changes in real-time, in contrast to mammalian models where nephrons are inaccessible because the kidneys are structurally complex systems internalized within the animal. Recent studies have employed the aminoglycoside gentamicin as a toxic causative agent for study of AKI and subsequent renal failure: gentamicin and other antibiotics have been shown to cause AKI in humans, and researchers have formulated methods to use this agent to trigger kidney damage in zebrafish7,8. However, the effects of aminoglycoside toxicity in zebrafish larvae are catastrophic and lethal, which presents a difficulty when studying epithelial regeneration and function over time. Our method presents the use of targeted cell ablation as a novel tool for the study of epithelial injury in zebrafish. Laser ablation gives researchers the ability to induce cell death in a limited population of cells. Varying areas of cells can be targeted based on morphological location, function, or even expression of a particular cellular phenotype. Thus, laser ablation will increase the specificity of what researchers can study, and can be a powerful new approach to shed light on the mechanisms of renal epithelial regeneration. This protocol can be broadly applied to target cell populations in other organs in the zebrafish embryo to study injury and regeneration in any number of contexts of interest.

Acute kidney injury (AKI) in humans is a common clinical problem caused by damage to the epithelial cells that comprise kidney nephrons, and AKI is associated with high mortality rates of 50-70%1. Following epithelial cell destruction, nephrons have a limited ability to regenerate, though the mechanisms and limitations that guide this phenomenon remain poorly understood. In this video article, we describe our technique for targeted laser ablation of kidney nephron cells in the zebrafish embryo kidney, or pronephros. Our new method can be used to complement nephrotoxicity-induced models of AKI and gain a high-resolution understanding of the cell and molecular alterations that are associated with epithelial regeneration in the kidney nephron.

激光烧蚀斑马鱼Pronephros研究肾小管上皮再生

Acute kidney injury (AKI) is characterized by high mortality rates from deterioration of renal function over a period of hours or days that culminates in ...

科研

生物学

Pharmacological and Functional Genetic Assays to Manipulate Regeneration of the Planarian Dugesia japonica

Free-living planarian flatworms have a long history of experimental usage owing to their remarkable regenerative abilities1. Small fragments excised from these animals reform the original body plan following regeneration of missing body structures. For example if a 'trunk' fragment is cut from an intact worm, a new 'head' will regenerate anteriorly and a 'tail' will regenerate posteriorly restoring the original 'head-to-tail' polarity of body structures prior to amputation (Figure 1A).
Regeneration is driven by planarian stem cells, known as 'neoblasts' which differentiate into ~30 different cell types during normal body homeostasis and enforced tissue regeneration. This regenerative process is robust and easy to demonstrate. Owing to the dedication of several pioneering labs, many tools and functional genetic methods have now been optimized for this model system. Consequently, considerable recent progress has been made in understanding and manipulating the molecular events underpinning planarian developmental plasticity2-9.
The planarian model system will be of interest to a broad range of scientists. For neuroscientists, the model affords the opportunity to study the regeneration of an entire nervous system, rather than simply the regrowth/repair of single nerve cell process that typically are the focus of study in many established models. Planarians express a plethora of neurotransmitters10, represent an important system for studying evolution of the central nervous system11, 12 and have behavioral screening potential13, 14. 
Regenerative outcomes are amenable to manipulation by pharmacological and genetic apparoaches. For example, drugs can be screened for effects on regeneration simply by placing body fragments in drug-containing solutions at different time points after amputation. The role of individual genes can be studied using knockdown methods (in vivo RNAi), which can be achieved either through cycles of microinjection or by feeding bacterially-expressed dsRNA constructs8, 9, 15. Both approaches can produce visually striking phenotypes at high penetrance- for example, regeneration of bipolar animals16-21. To facilitate adoption of this model and implementation of such methods, we showcase in this video article protocols for pharmacological and genetic assays (in vivo RNAi by feeding) using the planarian Dugesia japonica.

Pharmacological and Functional Genetic Assays to Manipulate Regeneration of the Planarian Dugesia japonica

An attractive model for studying stem cell differentiation within a live animal is the planarian flatworm. Regeneration is studied by simple amputation experiments that are easily performed in a basic laboratory and are amenable to pharmacological and genetic (in vivo RNAi) manipulation as detailed by protocols in this article.

药理和功能的遗传分析处理涡虫的再生日本三角涡虫</em

Free-living planarian flatworms have a long history of experimental usage owing to their remarkable regenerative abilities1. Small fragments excised from ...

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 ...

Gavaging Adult Zebrafish

The zebrafish has become an important in vivo model in biomedical research. Effective methods must be developed and utilized to deliver compounds or agents in solutions for scientific research. Current methods for administering compounds orally to adult zebrafish are inaccurate due to variability in voluntary consumption by the fish. A gavage procedure was developed to deliver precise quantities of infectious agents to zebrafish for study in biomedical research. Adult zebrafish over 6 months of age were anesthetized with 150 mg/L of buffered MS-222 and gavaged with 5 &mu;l of solution using flexible catheter implantation tubing attached to a cut 22-G needle tip. The flexible tubing was lowered into the oral cavity of the zebrafish until the tip of the tubing extended past the gills (approximately 1 cm). The solution was then injected slowly into the intestinal tract. This method was effective 88% of the time, with fish recovering uneventfully. This procedure is also efficient as one person can gavage 20-30 fish in one hour. This method can be used to precisely administer agents for infectious diseases studies, or studies of other compounds in adult zebrafish.

The increasing use of zebrafish as an animal model requires the development of effective methods for the delivery of known quantities of compounds and solutions. The gavage procedure described below allows for the oral delivery of precise volumes of solution reliably, safely and efficiently to adult zebrafish.

Gavaging成年斑马鱼

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

An Assay for Lateral Line Regeneration in Adult Zebrafish

Due to the clinical importance of hearing and balance disorders in man, model organisms such as the zebrafish have been used to study lateral line development and regeneration. The zebrafish is particularly attractive for such studies because of its rapid development time and its high regenerative capacity. To date, zebrafish studies of lateral line regeneration have mainly utilized fish of the embryonic and larval stages because of the lower number of neuromasts at these stages. This has made quantitative analysis of lateral line regeneration/and or development easier in the earlier developmental stages. Because many zebrafish models of neurological and non-neurological diseases are studied in the adult fish and not in the embryo/larvae, we focused on developing a quantitative lateral line regenerative assay in adult zebrafish so that an assay was available that could be applied to current adult zebrafish disease models. Building on previous studies by Van Trump et al.17&#160;that described procedures for ablation of hair cells in adult Mexican blind cave fish and zebrafish (Danio rerio), our assay was designed to allow quantitative comparison between control and experimental groups. This was accomplished by developing a regenerative neuromast standard curve based on the percent of neuromast reappearance over a 24 hr time period following gentamicin-induced necrosis of hair cells in a defined region of the lateral line. The assay was also designed to allow extension of the analysis to the individual hair cell level when a higher level of resolution is required.

Because many zebrafish models of neurological and non-neurological diseases are studied in the adult fish rather than the embryo/larvae, we developed a quantitative lateral line regenerative assay that can be applied to adult zebrafish disease models. The assay involved resolution at the 1) neuromast and 2) individual hair cell levels.

对于侧线再生成年斑马鱼的含量

Due to the clinical importance of hearing and balance disorders in man, model organisms such as the zebrafish have been used to study lateral line ...

Gap Junctional Intercellular Communication: A Functional Biomarker to Assess Adverse Effects of Toxicants and Toxins, and Health Benefits of Natural Products

This protocol describes a scalpel loading-fluorescent dye transfer (SL-DT) technique that measures intercellular communication through gap junction channels, which is a major intercellular process by which tissue homeostasis is maintained. Interruption of gap junctional intercellular communication (GJIC) by toxicants, toxins, drugs, etc. has been linked to numerous adverse health effects. Many genetic-based human diseases have been linked to mutations in gap junction genes. The SL-DT technique is a simple functional assay for the simultaneous assessment of GJIC in a large population of cells. The assay involves pre-loading cells with a fluorescent dye by briefly perturbing the cell membrane with a scalpel blade through a population of cells. The fluorescent dye is then allowed to traverse through gap junction channels to neighboring cells for a designated time. The assay is then terminated by the addition of formalin to the cells. The spread of the fluorescent dye through a population of cells is assessed with an epifluorescence microscope and the images are analyzed with any number of morphometric software packages that are available, including free software packages found on the public domain. This assay has also been adapted for in vivo studies using tissue slices from various organs from treated animals. Overall, the SL-DT assay can serve a broad range of in vitro pharmacological and toxicological needs, and can be potentially adapted for high throughput set-up systems with automated fluorescence microscopy imaging and analysis to elucidate more samples in a shorter time.

This protocol describes a scalpel loading-fluorescent dye transfer technique that measures intercellular communication through gap junction channels. Gap junctional intercellular communication is a major cellular process by which tissue homeostasis is maintained and disruption of this cell signaling has adverse health effects.

间隙连接通讯：天然产物的生物标志物的功能，以评估毒物和毒素的不利影响，以及健康的益处

This protocol describes a scalpel loading-fluorescent dye transfer (SL-DT) technique that measures intercellular communication through gap junction ...

Immunolabelling Myofiber Degeneration in Muscle Biopsies

The necrosis of muscle fibres (myonecrosis) plays a central role in the pathogenesis of several muscle conditions, including muscular dystrophies. Therapeutic options addressing the causes of muscular dystrophy pathogenesis are expected to alleviate muscle degeneration. Therefore, a method to assay and quantify the extent of cell death in muscle biopsies is needed. Conventional methods to observe myofiber degeneration in situ are either poorly quantitative or rely on the injection of vital dyes. In this article, an immunofluorescence protocol is described that stains necrotic myofibers by targeting immunoglobulin G (IgG) uptake by myofibers. The IgG uptake method is based on cell features characterizing the necrotic demise, including 1) the loss of plasma membrane integrity with the release of damage-associated molecular patterns and 2) the uptake of plasmatic proteins. In murine cross-sections, the co-immunolabelling of myofibers, extracellular matrix proteins, and mouse IgG allows clean and straightforward identification of myofibers with necrotic fate. This simple method is suitable for quantitative analysis and applicable to all species, including human samples, and does not require the injection of vital dye. The staining of necrotic myofibers by IgG uptake can also be paired with other co-immunolabelling.

Described here is a protocol for direct immunolabelling of necrotic myofibers in muscle cryosections. Necrotic cells are permeable to serum proteins, including immunoglobulin G (IgG). Revealing the uptake of IgG by myofibers allows the identification and quantification of myofibers that undergo necrosis regardless of muscle condition.

肌肉活检中的免疫标记肌纤维退化

The necrosis of muscle fibres (myonecrosis) plays a central role in the pathogenesis of several muscle conditions, including muscular dystrophies. ...

Nitroreductase/Metronidazole-Mediated Ablation and a MATLAB Platform (RpEGEN) for Studying Regeneration of the Zebrafish Retinal Pigment Epithelium

The retinal pigment epithelium (RPE) resides at the back of the eye and performs functions essential for maintaining the health and integrity of adjacent retinal and vascular tissues. At present, the limited reparative capacity of mammalian RPE, which is restricted to small injuries, has hindered progress to understanding in vivo RPE regenerative processes. Here, a detailed methodology is provided to facilitate the study of in vivo RPE repair utilizing the zebrafish, a&#160;vertebrate model capable of robust tissue regeneration. This protocol describes a transgenic nitroreductase/metronidazole (NTR/MTZ)-mediated injury paradigm (rpe65a:nfsB-eGFP), which results in ablation of the central two-thirds of the RPE after 24 h treatment with MTZ, with subsequent tissue recovery. Focus is placed on RPE ablations in larval zebrafish and methods for testing the effects of pharmacological compounds on RPE regeneration are also outlined. Generation and validation of RpEGEN, a MATLAB script created to automate quantification of RPE regeneration based on pigmentation, is also discussed. Beyond active RPE repair mechanisms, this protocol can be expanded to studies of RPE degeneration and injury responses as well as the effects of RPE damage on adjacent retinal and vascular tissues, among other cellular and molecular processes. This zebrafish system holds significant promise in identifying genes, networks, and processes that drive RPE regeneration and RPE disease-related mechanisms, with the long-term goal of applying this knowledge to mammalian systems and, ultimately, toward therapeutic development.

Nitroreductase/Metronidazole-Mediated Ablation and a MATLAB Platform RpEGEN for Studying Regeneration of the Zebrafish Retinal Pigment Epithelium

This protocol describes the methodology to genetically ablate the retinal pigment epithelium (RPE) using a transgenic zebrafish model. Adapting the protocol to incorporate signaling pathway modulation using pharmacological compounds is extensively detailed. A MATLAB platform for quantifying RPE regeneration based on pigmentation was developed and is presented and discussed.

硝基还原酶/甲硝唑介导的消融和MATLAB平台（RpEGEN）研究斑马鱼视网膜色素上皮的再生

The retinal pigment epithelium (RPE) resides at the back of the eye and performs functions essential for maintaining the health and integrity of adjacent ...

Efficient and Consistent Generation of Retinal Pigment Epithelium/Choroid Flatmounts from Human Eyes for Histological Analysis

The retinal pigment epithelium (RPE) and retina are functionally and structurally connected tissues that work together to regulate light perception and vision. Proteins on the RPE apical surface are tightly associated with proteins on the photoreceptor outer segment surface, making it difficult to consistently separate the RPE from the photoreceptors/retina. We developed a method to efficiently separate the retina from the RPE of human eyes to generate complete RPE/choroid and retina flatmounts for separate cellular analysis of the photoreceptors and RPE cells. An intravitreal injection of a high-osmolarity solution of D-mannitol, a sugar not transported by the RPE, induced the separation of the RPE and retina across the entire posterior chamber without causing damage to the RPE cell junctions. No RPE patches were observed attached to the retina. Phalloidin labeling of actin showed RPE shape preservation and allowed morphometric analysis of the entire epithelium. An artificial intelligence (AI)-based software was developed to accurately recognize and segment the RPE cell borders and quantify 30 different shape metrics. This dissection method is highly reproducible and can be easily extended to other animal models.

We describe a method to efficiently separate retinal pigment epithelium (RPE) from the retina in human eyes and generate whole RPE/choroid flatmounts for histological and morphometric analyses of the RPE.

从人眼高效、一致地生成视网膜色素上皮/脉络膜平面安装，用于组织学分析

The retinal pigment epithelium (RPE) and retina are functionally and structurally connected tissues that work together to regulate light perception and ...