手术消融分析在研究涡虫再生眼
Summary
该协议示出如何一致切除涡眼（光杯），而不干扰周围的组织。使用胰岛素针和注射器，任一个或两个的眼睛可以被烧蚀以促进调查调节眼再生，再生视觉的演变，和光诱导行为的神经基础的机制。
Abstract
在成体干细胞和再生机制的研究中，涡虫扁虫是在体内模型系统中的缝钉。这是因为在很大程度上他们丰富的多能干细胞群和伤害，这将是灾难性的大多数动物后再生的所有细胞和组织类型的能力。近日，涡已经得到普及，作为眼睛再生的典范。其再生整个眼睛能力（包括两种组织类型：色素细胞和光感受器）允许用于调节视觉系统再生机制的清扫。眼消融具有用于检查眼睛特定的途径和机制，其中最重要的是，再生在很大程度上仅仅局限于眼组织上的其他技术（如断头或打孔）几个优点。这个视频本文的目的是演示如何可靠地除去涡视杯，而不会干扰脑或周围组织。蠕虫和已建立的细胞集落的维护的处理也被描述。这种技术使用一个31克，5 / 16-英寸胰岛素针手术舀出固定化在冷板涡虫的视杯。此方法既包括单，双眼烧蚀，与眼睛在1-2周内再生，从而允许一个宽范围的应用。特别地，该消融技术可以很容易地与为了更好地理解的再生机制及其演进，眼干细胞和它们的维护，和phototaxic行为反应和它们的神经学基础的药理学和遗传学（RNA干扰）屏结合。
Introduction
涡虫是研究成体干细胞介导再生一个功能强大的模式生物。这些非寄生的扁虫淡水拥有再生的任何及所有丢失的组织，包括他们的中枢神经系统和大脑1的能力。研究早在1700年2，技术在涡领域在过去10 – 15年的进展（如基因组测序， 原位杂交，免疫组织化学，RNA干扰（RNAi），和转录）已经更新了这个历史的模式生物。具体来说，涡虫最近获得了普及作为眼科研究3一个新兴的模式。
涡具有只有两种组织类型，在感光体的神经元和色素细胞原型眼睛;这使得它的眼干细胞群的鉴定和证明，许多相同的基因调节脊椎动物的眼睛去velopment是保守的涡虫4,5。光学杯位于背侧和包括感光体神经元的白色，无颜料的树突和所述半月形黑色素细胞，眼睛经由视交叉支配脑。除了作为用于阐明再生过程6所述的模型，涡虫眼是非常适合于学习的视觉机构7的演变，行为反应的光（涡显示负趋光）8，和行为9的神经学基础。
在涡眼再生大部分已经研究主要有两种情况：作为头再生的一部分以下断头4，图 10和以下只是眼部组织11的切除，12 </SUP>。眼睛上再生涡虫的大多数研究都使用了断头方法，因为它是简单明了。最常见的涡眼切除方法迄今通过打孔器是用细玻璃毛细管13，14，但也有一些研究也已经进行截肢仅次于眼（局部断头）15。然而，所有的这些方法涉及的不仅仅是眼睛许多其他组织（如脑，肠，肾管）的损失，潜在的复杂结果的解释。这里介绍的眼睛消融协议限制切除到更特定于眼内的眼组织（特别排除脑），导致数据。另外，称取7-14天，开始馈送断头蠕虫不同，眼烧蚀蠕虫将消融12的24小时内进料，允许RNAi实验（其中的RNAi经由食物递送）被performeð兼任。
虽然眼睛消融术在技术上是很难比斩首成功执行，涉及眼切除目前的研究尚未包括在他们的程序的详细说明。这个视频文章的目的是为了使研究人员能够一致地删除涡视杯，而不会干扰底层的脑组织和撤除其他一些组织成为可能。此方法可用于单和双眼消融，并适用于广泛的调查。像大多数再生试验中，眼消融非常适合结合两者的药理学和遗传学（RNAi）的屏幕，以及行为研究。这里，我们介绍的方法蠕虫的处理，保持了涡虫的殖民地，和眼睛消融技术本身。
Protocol
1.动物文化和处理注：此协议使用Schmidtea地中海 ，二倍体涡物种，基因组测序16，17是常用的再生研究。然而，该测定法是与其他物种，诸如Girardia虎纹和Girardia dorotocephala（它们是可商购）同样成功。 保持“蠕虫水”为0.5g / L海盐超纯（或过滤的去离子）水制成蠕虫。使用无菌聚丙烯或玻璃容器来?…
Representative Results
对于第1-2小时手术后，动物可能比完整的蠕虫（但是他们仍然会移动）表现出下降的运动。如果需要的话，蠕虫将在外科手术后24个小时内吃（例如，RNAi的馈送）。在之后一段时间内同一个人的眼睛再生时，确保每次取虫的照片既手术（完好）之前，在1个小时后消融（HPA）。 4天后消融（DPA）再生色素细胞应该是可见的，并且通过14 DPA整个眼睛将有完全再生（ 图3A-B…
Discussion
此眼消融技术提高了对当前方法（如打孔）通过排除脑组织和主要限制切除到眼组织中。通过实践，这项技术可以被大多数人来执行，技术人员在显微外科经验不足，但认真的本科生经历。因此建议该技术使用在实验的消融，包括通过免疫组织化学或在眼睛标志物4，5，13 原位杂交（如果可能）完全去除所有眼部?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
笔者想感谢米歇尔·德奇为完善这一眼消融技术，泰勒·伯克霍尔茨与功能测试援助，迈克尔·勒文的抗抑制蛋白抗体，而顺治Morokuma为珀尔帖板信息。这项工作是由西密歇根大学WSB的SFSA资助。
Materials
| Instant Ocean sea salts | Spectrum Brands | SS15-10 | "10 Gallon" box (net weight 3 lbs) |
| Kimwipes EX-L lint-free tissue wipe | Kimberly-Clark | 34155 | 4.5 x 8.5 in |
| Whatman #2 filter paper | Sigma | WHA1002125 | Circles, 125 mm diameter, white |
| Easy Touch Insulin syringe (with needle) | Pet Health Market | 17175-04 | U-100 1 cc syringe, 31-gauge 5/16 in needle |
| 100 mm Petri dish | VWR | 25384-342 | 100 x 15 mm |
| 60 mm Petri dish | VWR | 25384-092 | 60 x 15 mm |
| Dumont #5 forceps | Fine Science Tools | 11254-20 | Inox, straight tip , 11 cm |
| Transfer pipettes | Samco Scientific | 225 | Graduated, large bulb, 7.5 mL, non sterile |
| Parafilm M paraffin film | Brand | 701606 | 4 in x 125 ft roll |
| 12-well untreated tissue culture plate | VWR | 15705-059 | Untreated, flat bottom, sterile, Falcon brand |
| Plastic food containers (for colony) | Ziploc | Large rectangle | 2.25 qt (2.12 L), 10" x 6 -3/4 " x 3 -3/16" |
| Planaria (Girardia tigrina) | Carolina Biological | 132954 | Sold as "Brown" Planaria; most often they are G. tigrina (aka Dugesia tigrina), but sometimes are G. dorotocephala (aka Dugesia dorotocephala); either will work. |
| Planaria (Schmidtea mediterranea) | n/a | n/a | S. mediterranea are not commercially available. At this time animals are only obtainable from laboratories that use them and have extra animals. |
| Brown paper towels | Grainger | 2U229 | 9-3/16 x 9-3/8" 1-Ply Multifold Paper Towel, UNBLEACHED |
| Wash bottle (for worm water), optional | VWR | 16650-275 | Wash Bottles, Low-Density Polyethylene, Wide Mouth, 500 mL |
| Anti-synapsin antibody, optional | Developmental Studies Hybridoma Bank | 3C11 | Supernatant |
| Anti-arrestin antibody, optional | n/a | n/a | Not commercially available. Kind gift from Michael Levin, Tufts University |
| Nalgene Lowboy carboy with spigot (for storing worm water), optional | Nalge Nunc International Corporation | 2324-0015 | 15 L, polypropylene, low profile makes it easier to fill plastic colony containers |
| Custom Peltier plate, optional | Williams Machine, Foxboro, MA | n/a | Design specifics courtesy of Junji Morokuma, Tufts University: Peltier plate is constructed of a standard thermoelectric heat pump (for example, All Electronics Corp Catalog # PJT-1, 30 mm2). The square heat pump is covered with a thin mirrored surface, then placed inside a 30 mm2 square hole in a circular plexiglass form (~50 mm in diameter). This form is of similar thickness to the heat pump, and fits flush into a well tooled in the center of a round heat sink (~115 mm in diameter). The form/heat pump is "anchored" to the sink with silicone base heat sink compound. The leads are threaded through holes drilled through both the form and the the heat sink. The bottom half of the heat sink is tooled into a "foot" that fits into the opening of your microscope's base plate. |
| DC power source (for Peltier plate), optional | B & K Precision | 1665 | Regulated Low Voltage DC Power Supply, 1-18 volts (DC), 1-10 amps. |
| Other common supplies | |||
| Gloves | |||
| Razor blade | |||
| Scissors | |||
| Dissecting scope with gooseneck lighting | |||
| Chopstick rests, optional |
References
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Cite This Article
Morton, J. M., Saad, M. A., Beane, W. S. Surgical Ablation Assay for Studying Eye Regeneration in Planarians. J. Vis. Exp. (122), e55594, doi:10.3791/55594 (2017).