Name: technique to target microinjection to the developing xenopus kidney
Uploaded: 2016-05-03T11:00:00
Description: Watch this Scientific Journal Video about Technique to Target Microinjection to the Developing Xenopus Kidney at JoVE.com

这项工作是由儿科得克萨斯麦戈文医学院的大学卫生署授予NIDDK（K01DK092320）和启动资金的国家机构提供支持。

下面的协议已获得得克萨斯大学健康科学中心在休斯顿的中心实验室动物医学动物福利委员会，作为机构护理和使用委员会大学（协议＃：HSC-AWC-13-135）。 1.识别和选择卵裂球的肾靶向注射<ol><li>之前产生的胚胎，使用爪蟾发展21的正常表理解在胚胎早期的细胞分裂的方向。或者，在Xenbase 11 爪蟾的早期发育阶段的访问的图。 </li><li>访问Xenbase 11交互?...

<ol>
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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=.">.</a> Early Development of Xenopus laevis. A Laboratory Manual. , (2000).</li><li>Miller, R. K., Lee, M., McCrea, P. D., Kloc, M., Kubiak, J. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Xenopus+pronephros:+A+kidney+model+making+leaps+toward+understanding+tubule+development.">The Xenopus pronephros: A kidney model making leaps toward understanding tubule development.</a> Xenopus Development. , 215-238 (2014).</li><li>Lienkamp, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vertebrate+kidney+tubules+elongate+using+a+planar+cell+polarity-dependent+rosette-based+mechanism+of+convergent+extension.">Vertebrate kidney tubules elongate using a planar cell polarity-dependent rosette-based mechanism of convergent extension.</a> Nat. Genet. 44 (12), 1382-1387 (2012).</li><li>Lyons, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Requirement+of+Wnt/&#946;-catenin+signaling+in+pronephric+kidney+development.">Requirement of Wnt/&#946;-catenin signaling in pronephric kidney development.</a> Mech. Dev. 126 (3-4), 142-159 (2009).</li><li>Miller, R. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pronephric+tubulogenesis+requires+Daam1-mediated+planar+cell+polarity+signaling.">Pronephric tubulogenesis requires Daam1-mediated planar cell polarity signaling.</a> J. Am. Soc. Nephrol. 22, 1654-1667 (2011).</li><li>Vize, P. D., Jones, E. A., Pfister, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+Xenopus+pronephric+system.">Development of the Xenopus pronephric system.</a> Dev. Biol. 171 (2), 531-540 (1995).</li><li>Miller, R. K., Lee, M., McCrea, P. D., Kloc, M., Kubiak, J. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+12:+The+Xenopus+Pronephros:+A+Kidney+Model+Making+Leaps+toward+Understanding+Tubule+Development.">Chapter 12: The Xenopus Pronephros: A Kidney Model Making Leaps toward Understanding Tubule Development.</a> Xenopus Development. , (2014).</li><li>Taira, M., Otani, H., Jamrich, M., Dawid, I. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+LIM+class+homeobox+gene+Xlim-1+in+pronephros+and+CNS+cell+lineages+of+Xenopus+embryos+is+affected+by+retinoic+acid+and+exogastrulation.">Expression of the LIM class homeobox gene Xlim-1 in pronephros and CNS cell lineages of Xenopus embryos is affected by retinoic acid and exogastrulation.</a> Development. 120, 1525-1536 (1994).</li><li>Weber, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+and+function+of+the+tissue-specific+transcription+factor+HNF1+alpha+(LFB1)+during+Xenopus+development.">Regulation and function of the tissue-specific transcription factor HNF1 alpha (LFB1) during Xenopus development.</a> Int. Dev. Biol. 40 (1), 297-304 (1996).</li><li>Carroll, T. J., Vize, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synergism+between+Pax-8+and+lim-1+in+embryonic+kidney+development.">Synergism between Pax-8 and lim-1 in embryonic kidney development.</a> Dev. Biol. 214 (1), 46-59 (1999).</li><li>Etkin, L. D., Pearman, B., Ansah-Yiadom, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replication+of+injected+DNA+templates+in+Xenopus+embryos.">Replication of injected DNA templates in Xenopus embryos.</a> Exp. Cell Res. 169 (2), 468-477 (1987).</li><li>Vize, P. 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+chloride+conductance+channel+ClC-K+is+a+specific+marker+for+the+Xenopus+pronephric+distal+tubule+and+duct.">The chloride conductance channel ClC-K is a specific marker for the Xenopus pronephric distal tubule and duct.</a> Gene Expr. Patterns. 3 (3), 347-350 (2003).</li><li>Uochi, T. S., Takahashi, S., Ninomiya, H., Fukui, A., Asashima, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Na+,+K+-ATPase+alpha+subunit+requires+gastrulation+in+the+Xenopus+embryo.">The Na+, K+-ATPase alpha subunit requires gastrulation in the Xenopus embryo.</a> Dev. Growth Differ. 39 (5), 571-580 (1997).</li><li>Nieuwkoop, P. D., Faber, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Normal table of Xenopus laevis (Daudin): A systematical &amp; chronological survey of the development from the fertilized egg till the end of metamorphosis. , (1994).</li><li>Ubbels, G. A., Hara, K., Koster, C. H., Kirschner, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+a+functional+role+of+the+cytoskeleton+in+determination+of+the+dorsoventral+axis+in+Xenopus+laevis+eggs.">Evidence for a functional role of the cytoskeleton in determination of the dorsoventral axis in Xenopus laevis eggs.</a> J. Embryol. Exp. Morphol. 77, 15-37 (1983).</li><li>Huang, S., Johnson, K. E., Wang, H. 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针对发展中爪蟾胚胎的前肾依赖于识别和注入正确的卵裂球。 8细胞胚胎的卵裂球V2的注射靶向左侧前肾18。这留下对侧右前肾作为内部对照。如果啉拦截或RNA表达用于改变肾发展，对侧右前肾可用于基因敲除或过表达的影响进行比较的左前肾。在这种情况下，如不匹配的控制啉或显性负RNA构建适当的控制应除了对侧内部控制用于分析基因表达的变化的结果。由于爪蟾胚胎的?...

非洲爪蟾胚胎肾中，前肾，是研究肾脏发育和疾病的良好模式。胚胎外部发展，在尺寸是大的，可以大量生产，并通过微注射或外科手术容易操纵。此外，治在哺乳动物和两栖动物肾脏发育的基因是保守的。哺乳动物的肾脏通过三个阶段进行：在头肾，中肾，后肾和1，而两栖类胚胎有前肾和成人两栖动物有后肾。这些肾脏形式的基本滤波单元是肾，和哺乳动物和两栖类所需要的相同的信号级联和电感事件接受nephrogenesis 2，3， 爪蟾前肾包含近端，中间，远端和连接管组成的单肾，和血管球（类似于哺乳动物肾小球）1，4-6（ 图1 </str翁&gt;）。大存在于非洲爪蟾前肾单肾使得它适合作为用于参与肾发育和疾病过程的基因的研究中一个简单的模型。 细胞命运的地图已经建立了早期的爪蟾胚胎，并且是免费提供的Xenbase 7-11在线。在这里，我们描述了用于谱系示踪剂定位的显影爪前肾的显微注射的技术，虽然同样的技术可以适用于针对其它组织，如心脏或眼睛。谱系示踪剂是标签（包括活体染料，荧光标记的葡聚糖，组织化学可检测的酶，和mRNA编码荧光蛋白），可以注射到早期卵裂球，使该细胞的后代的发育过程中的可视化。这个协议利用MEM-RFP的mRNA，编码膜靶向红色荧光蛋白12，作为一个谱系示踪剂。有针对性的显微注射技术在这里描述的4-和8细胞胚胎niques单个卵裂球可以用于注射吗啉击倒的基因表达，或与外源RNA过表达感兴趣的基因。通过注入腹侧，植物卵裂球，主要是胚胎的前肾将有针对性，留下对侧前肾作为发育控制。示踪剂联合注射验证正确的卵裂球注射，并显示该组织中的胚胎从卵裂球注入出现，验证了前肾定位。在头肾的免疫染色允许有多好pronephric肾小管已经有针对性的可视化。过度表达和敲低效果然后可以对胚，其用作发育控制的对侧得分，并且可以用于计算pronephric索引13。细胞命运地图的可用性允许使用这种有针对性的显微注射技术对靶组织OTH尔比前肾，和荧光示踪剂的共注射允许有针对性的显微注射到每个组织分析前进行验证。 期间胚胎显微注射，发育温度应严格调节，因为爪蟾发展的速率在 ​​很大程度上取决于它14。 （ - 16°C 14）为4和8细胞注射，因为开发时间减慢的胚胎应该稍凉培养。在22℃，从第1阶段（1细胞）的开发时间到阶段3（4细胞）是约2小时，同时在16℃下的开发时间到阶段3是约4小时。这需要大约15分钟从4细胞的胚胎去8芯（4级），胚胎在22°C，但在16℃，大约需要30分钟。同样地，在22℃，只需要30分钟的8细胞胚胎进步到16细胞胚胎（阶段5）。这个时间是在16℃增加至45分钟。该refore，是有用的减缓胚胎的发育率，以使有足够的时间在8细胞期注射前胚胎进步到16单元的阶段。此外，生长温度可以调节，以加快或减慢胚胎发育，直至肾脏已发育完全。 蝌蚪级爪蟾胚胎的表皮是相对透明的，允许未经组织15的清扫或清除显影前肾的容易成像。由于爪蟾胚胎的相对透明度，活细胞成像也是可行16,17。整个安装免疫染色以可视化的前肾可能带有该标签的近端，中间，远端和舞台的连接管38建立抗体- 40胚胎允许pronephric发展评价靶基因表达的操作后爪蟾胚胎18-20。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Sodium chloride</td>
			<td>Fisher</td>
			<td>S271-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium chloride</td>
			<td>Fisher</td>
			<td>P217-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium sulfate&#160;</td>
			<td>Fisher</td>
			<td>M63-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Fisher</td>
			<td>C79-500</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Fisher</td>
			<td>BP310-500</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Fisher</td>
			<td>S311-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Gentamycin solution, 50 mg/mL</td>
			<td>Amresco</td>
			<td>E737-20ML</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Cysteine, 99%+</td>
			<td>Acros Organics</td>
			<td>52-90-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Ficoll</td>
			<td>Fisher</td>
			<td>BP525-100</td>
			<td></td>
		</tr>
		<tr>
			<td>100 mm x 15 mm Petri dish</td>
			<td>Fisher</td>
			<td>FB0875712</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini Fridge II</td>
			<td>Boekel</td>
			<td>260009</td>
			<td>Benchtop incubator for embryos.</td>
		</tr>
		<tr>
			<td>Gap43-RFP plasmid</td>
			<td></td>
			<td></td>
			<td>For making tracer RNA. Ref: Davidson et al., 2006.</td>
		</tr>
		<tr>
			<td>Rhodamine dextran, 10,000 M.W.</td>
			<td>Invitrogen</td>
			<td>D1817</td>
			<td>Tracer.</td>
		</tr>
		<tr>
			<td>Molecular biology grade, USP sterile purified water</td>
			<td>Corning</td>
			<td>46-000-CI</td>
			<td></td>
		</tr>
		<tr>
			<td>7&#34; Drummond replacement tubes</td>
			<td>Drummond</td>
			<td>3-000-203-G/XL</td>
			<td>Microinjection needles.</td>
		</tr>
		<tr>
			<td>Needle puller</td>
			<td>Sutter Instruments</td>
			<td>P-30</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine forceps</td>
			<td>Dumont</td>
			<td>11252-30</td>
			<td>For breaking microinjection needle tip.</td>
		</tr>
		<tr>
			<td>Nanoject II</td>
			<td>Drummond</td>
			<td>3-000-204</td>
			<td>Microinjector.</td>
		</tr>
		<tr>
			<td>Mineral oil, heavy</td>
			<td>Fisher</td>
			<td>CAS 8042-47-5</td>
			<td>Oil for needles.</td>
		</tr>
		<tr>
			<td>27G monoject hypodermic needle</td>
			<td>Covidien</td>
			<td>8881200508</td>
			<td>For loading mineral oil into microinjection needle.</td>
		</tr>
		<tr>
			<td>5 mL Luer-Lok syringe</td>
			<td>BD</td>
			<td>309646</td>
			<td>For loading mineral oil into microinjection needle.</td>
		</tr>
		<tr>
			<td>60 mm x 15 mm Petri dish</td>
			<td>Fisher</td>
			<td>FB0875713A</td>
			<td></td>
		</tr>
		<tr>
			<td>800 micron polyester mesh</td>
			<td>Small Parts</td>
			<td>CMY-0800-C</td>
			<td></td>
		</tr>
		<tr>
			<td>Transfer pipets</td>
			<td>Fisher</td>
			<td>13-711-7M</td>
			<td>For transferring embryos. Cut off the tip so that the embryos are easily taken up by the pipette.</td>
		</tr>
		<tr>
			<td>6-well cell culture plate</td>
			<td>Nest Biotechnology</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>MOPS</td>
			<td>Fisher</td>
			<td>BP308-500</td>
			<td></td>
		</tr>
		<tr>
			<td>EGTA</td>
			<td>Acros Organics</td>
			<td>67-42-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Formaldehyde</td>
			<td>Fisher</td>
			<td>BP531-500</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mm x 45 mm screw thread vial</td>
			<td>Fisher</td>
			<td>03-339-25B</td>
			<td>For fixing, staining, and storing embryos.</td>
		</tr>
		<tr>
			<td>24-well cell culture plate</td>
			<td>Nest Biotechnology</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Benzocaine</td>
			<td>Spectrum</td>
			<td>BE130</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Fisher</td>
			<td>BP2818-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Fisher</td>
			<td>A412-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS) 1X powder</td>
			<td>Fisher</td>
			<td>BP661-50</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine serum albumen</td>
			<td>Fisher</td>
			<td>BP1600-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Fisher</td>
			<td>BP151-500</td>
			<td></td>
		</tr>
		<tr>
			<td>3D mini rocker, model 135</td>
			<td>Denville Scientific</td>
			<td>57281</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat serum, New Zealand origin</td>
			<td>Invitrogen</td>
			<td>16210064</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium azide</td>
			<td>Fisher</td>
			<td>S227I-25</td>
			<td></td>
		</tr>
		<tr>
			<td>Monoclonal 3G8 antibody</td>
			<td>European Xenopus Resource Centre</td>
			<td></td>
			<td>Primary antibody to label proximal tubules.</td>
		</tr>
		<tr>
			<td>Monoclonal 4A6 antibody</td>
			<td>European Xenopus Resource Centre</td>
			<td></td>
			<td>Primary antibody to label distal tubule and duct.</td>
		</tr>
		<tr>
			<td>anti-RFP pAb, purified IgG/rabbit</td>
			<td>MBL</td>
			<td>PM005</td>
			<td>Primary antibody to label Gap43-RFP tracer.</td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 goat anti-mouse IgG</td>
			<td>Life Technologies</td>
			<td>A11001</td>
			<td>Secondary antibody to label distal tubule and duct.</td>
		</tr>
		<tr>
			<td>Alexa Fluor 555 goat anti-rabbit IgG</td>
			<td>Life Technologies</td>
			<td>A21428</td>
			<td>Secondary antibody to label Gap43-RFP tracer.</td>
		</tr>
		<tr>
			<td>9 cavity spot plate</td>
			<td>Corning</td>
			<td>7220-85</td>
			<td></td>
		</tr>
		<tr>
			<td>Benzyl benzoate</td>
			<td>Fisher</td>
			<td>105862500</td>
			<td>Optional - for clearing embryos</td>
		</tr>
		<tr>
			<td>Benzyl alcohol</td>
			<td>Fisher</td>
			<td>A396-500</td>
			<td>Optional - for clearing embryos</td>
		</tr>
	</tbody>
</table>

technique to target microinjection to the developing xenopus kidney

的非洲爪 蟾 （蛙）中，前肾，胚胎肾由单个肾的，并且可以用作用于肾脏疾病的模型。 爪蟾胚胎是大的，外部发展，并且可以通过微注射或外科手术容易地操纵。此外，命运地图已经建立了早期的爪蟾胚胎。靶向显微注射到单个卵裂球，最终将产生的器官或感兴趣的组织可被用于选择性地过表达或该受限制区域内的击倒的基因表达，从而降低在发育中的胚胎的其余部分次级效应。在这个协议中，我们描述了如何利用建立的爪蟾的命运映射到显影爪蟾肾（该头肾），通过显微注射到目标的4和8细胞胚胎卵裂球专用。沿袭示踪剂的注入使得注入的具体目标的验证。胚胎已经开发到阶段38后 - 40，整个安装免疫染色被用于可视化pronephric发展，通过靶向的细胞的前肾的贡献可以被评估。同样的技术可以适于除了前肾靶向其它组织类型。

的4-和8-细胞爪蟾胚胎用MEM-RFP的mRNA显微注射表现出不同水平的靶向前肾的。 图4示出了级40的胚胎与正确的MEM-RFP的mRNA表达模式。胚胎在左腹侧卵裂球（ 图4A）注射，并分类为MEM-RFP的mRNA的适当的表达模式。除了在近端，中间，远端表达MEM-​​RFP与连接肾脏肾小管，正常注射的胚胎预计将显示荧光的头部，躯干和尾部的表皮。它们也应显示在...

Watch this Scientific Journal Video about Technique to Target Microinjection to the Developing Xenopus Kidney at JoVE.com

Technique to Target Microinjection to the Developing Xenopus Kidney

Here, we present a protocol to use fate maps and lineage tracers to target injections into individual blastomeres that give rise to the kidney of Xenopus laevis embryos.

技术目标显微注射到显影<em&gt;爪</em&gt;肾

The embryonic kidney of Xenopus&#160;laevis (frog), the pronephros, consists of a single nephron, and can be used as a model for kidney disease. Xenopus ...

The overall goal of this procedure is to target microinjections to the developing xenopus kidney. This method can help address key questions in the field of developmental biology such as how the kidney forms and what genes are important for this process. The main advantage of this technique is that it maximizes the delivery of microinjected reagents to a targeted tissue.Visualization of this method is important because identification of the correct blastomere for targeted microinjection is critical. To begin this procedure both testes were isolated from a single male frog and placed in a 60 millimeter petri dish filled with 10 millileters of testes storage solution. Then store the testes at four degress Celsius.Next, eggs were collected from a female frog in a 100 millimeter petri dish. Pour off excess water from the petri dish. After that cut off a quarter of a testis in Testes Storage Solution.Transfer the piece of testis to the petri dish containing the eggs. Subsequently, cut the testis portion into small pieces. Add MMR plus Gentamycin to the petri dish to cover the eggs.Mix them by swirling the dish and then wait approximately 30 minutes for fertilization to take place at room temperature. After fertilization the pigmented side of the embryos should be facing up. Remove MMR from the petri dish using a transfer pipette and add enough de-jelly solution to cover the embryos.Afterward, swirl the dish over the next few minutes to disolve the jelly coat on the embryos. Once the embryos are closely touching each other in the center of the dish, the jelly coat has been removed. Remove the de-jelly solution with a transfer pipette.Next, wash the de-jellied embryos 3 to 5 times in MMR plus Gentamycin by carefully pouring off the MMR and filling the dish with new MMR. Do not remove all of the MMR from the dish, which may damage the embryos. After that, remove any unfertilized eggs or pieces of testis from the petri dish.To stagger their development, place half of the embryos from a single fertilization in a petri dish kept at 14 degrees Celsius, and the other half of the embryos in a petri dish kept at 18 degrees Celsius. Embryos will develop more slowly at 14 degress Celsius than at 18 degress Celsius. Allowing for multiple sets of injections from a single fertilized clutch.Prepare the injection solution containing point zero one nanogram per nanoliter Membrane-bound Red Fluorescent Protein mRNA. While the embryos are developing to the 4-cell or 8-cell stage. Keep the injection solution on ice until use.Then, load a seven inch replacement glass capillary tube into a needle puller with the top of the replacement tube aligned with the top of the needle puller case. Set the heat number two value to 800 and the pull value to 650 and press the pull button to pull the needle. After that, snip off the tip of the pulled needle with a pair of Dumont forceps.Slip the micropipette collet onto the back of the needle. Next, slip the large hole O-ring onto the back of the needle behind the collet. Now, fill the needle with mineral oil using a 27 gauge hyperdermic needle, being careful not to get air bubbles into the needle.Slip the needle onto the plunger of the microinjector, seating the needle into the large hole of the white plastic spacer installed on the plunger. Secure the needle by tightening the collet. Next, press and hold the Empty"button on the microinjector control box until there are two beeps.Afterward, pipette three microliters of injection solution onto a piece of parafilm. Then, insert the tip of the needle into the bead of injection solution on the parafilm. Press and hold the Fill"button on the microinjector control box to draw the injection solution into the needle.Prior to microinjection, it is important to understand the early cell divisions of the xenopus embryo. The single cell embryo has a darkly pigmented, animal pole and a vegetal pole which is white and yoky. In the two cell embryo the first cleavage typically occurs between the left and right sides of the embryo.These cells contribute equally to the pronephric lineage. The second cleavage divides the dorsal and ventral halves of the embryo leading to a 4-cell embryo. The dorsal cells are smaller and have less pigment than the ventral cells.If injecting into a 4-cell embryo, inject the left ventral blastomere to target the left kidney. The third cleavage bi-sects the animal and vegetal sides. Resulting in an 8-cell embryo.At this point there are four animal blastomeres and four vegetal blastomeres. To target the left kidney of an 8-cell embryo inject into the left ventral vegetal blastomere. Subsequently, fill a 60 millimeter petri dish lined with 500 micron polyester mesh with five percent fycol in MMR plus Gentamycin.Carefully pipette 20 to 30 8-cell embryos into the dish. Using a hair loop manipulate the embryos so that the blastomere to be injected is facing the needle. To target the left kidney, line up the embryos so that the left ventral vegetal blastomeres of 8-cell embryos face the needle.Inject 10 nanoliters of injection solution into the selected blastomere of each embryo in the dish. Then, transfer the injected embryos into the wells of a culture plate with five percent fycol in MMR plus Gentamycin. Incubate the injected embryos at 16 degrees Celsius for approximately one to two hours to allow the injected blastomeres to heal.After that, transfer the microinjected embryos into new wells in the culture plate filled with MMR plus Gentamycin. Incubate the embryos at 14 to 22 degress Celsius until they reach stage 38 to 40. In this procedure transfer 10 to 20 stage 38 to 40 embryos into a glass vial.Add 10 microliters of five percent benzocaine in 100 percent ethanol to the vial. Mix by inverting the vial and wait 10 minutes to anesthetize the embryos. Next, remove MMR from the vial and fill it with MEMFA.Then, place it on a three dimensional, rocking platform for one hour at room temperature. After one hour remove MEMFA from the vial and fill it with 100 percent methanol. Then, place the vial on a three dimensional, rocking platform for ten minutes at room temperature.Repeat this wash step one more time and store the embryos in 100 percent methanol overnight at minus 20 degrees Celsius. Embryos are now fixed and ready for immunostaining. This schematic shows which blastomere to inject for targeting of the left pronephros of xenopus embryos at the 8-cell stage using Membrane-bound Red Fluorescent Protein mRNA as a tracer.Tracer locatlization after injection in the left ventral vegetal blastomere is shown in red while the kidney is labeled in green. This image shows that the kidney was stained green with antibodies 3G8 and 4A6. Here is a close up view of the kidney region showing tracer loacalization and here is the merged image showing the co-localization of the tracer with the kidney.Shown here is the confocal image of the kidney of a second embryo stained with 3G8 and 4A6. This is the localization of the red tracer in the kidney and surrounding tissue and this is the merged image showing the co-localization of the tracer 3G8 and 4A6 in the kidney. Prior to performing this procedure it's important to become familiar with the early xenopus embryo.This will allow you to properly target microinjections through the established xenopus fade map. Once mastered, this technique can be adapted to target other tissues such as the neural tube or heart.

technique-to-target-microinjection-to-the-developing-xenopus-kidney

Research

JoVE Journal

Developmental Biology

Technique to Target Microinjection to the Developing Xenopus Kidney

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development

Amphibian eggs have been widely used to study embryonic development. Early embryonic development is driven by maternally stored factors accumulated during oogenesis. In order to study roles of such maternal factors in early embryonic development, it is desirable to manipulate their functions from the very beginning of embryonic development. Conventional ways of gene interference are achieved by injection of antisense oligonucleotides (oligos) or mRNA into fertilized eggs, enabling under- or over-expression of specific proteins, respectively. However, these methods normally require more than several hours until protein expression is affected, and, hence, the interference of gene functions is not effective during early embryonic stages. Here, we introduce an experimental system in which expression levels of maternal proteins can be altered before fertilization. Xenopus laevis oocytes obtained from ovaries are defolliculated by incubating with enzymes. Antisense oligos or mRNAs are injected into defolliculated oocytes at the germinal vesicle (GV) stage. These oocytes are in vitro matured to eggs at the metaphase II (MII) stage, followed by intracytoplasmic sperm injection (ICSI). By this way, up to 10% of ICSI embryos can reach the swimming tadpole stage, thus allowing functional tests of specific gene knockdown or overexpression. This approach can be a useful way to study roles of maternally stored factors in early embryonic development.

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development

We describe methods of manipulating Xenopus laevis immature oocytes, in vitro maturation of oocytes to eggs, and intracytoplasmic sperm injection. This protocol allows degradation of some maternal proteins and overexpression of genes of interest at fertilization, and hence is valuable to study roles of specific factors in early embryonic development.

操作和<em&gt;在体外</em中&gt;成熟<em&gt;非洲爪蟾</em&gt;卵母细胞，其次是胞浆内单精子注射，研究胚胎发育

Amphibian eggs have been widely used to study embryonic development. Early embryonic development is driven by maternally stored factors accumulated during ...

科研

发育生物学

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the large size of their cells in early embryos, make Xenopus laevis a useful model for visualising GFP-tagged ligands. Synthetic mRNAs are efficiently translated after injection into early stage Xenopus embryos, and injections can be targeted to a single cell. When combined with a lineage tracer such as membrane tethered RFP, the injected cell (and its descendants) that are producing the overexpressed protein can easily be followed. This protocol describes a method for the production of fluorescently tagged Wnt and Shh ligands from injected mRNA. The methods involve the micro dissection of ectodermal explants (animal caps) and the analysis of ligand diffusion in multiple samples. By using confocal imaging, information about ligand secretion and diffusion over a field of cells can be obtained. Statistical analyses of confocal images provide quantitative data on the shape of ligand gradients. These methods may be useful to researchers who want to test the effects of factors that may regulate the shape of morphogen gradients.

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

The manuscript here provides a simple set of methods for analysing the secretion and diffusion of fluorescently tagged ligands in Xenopus. This provides a context for testing the ability of other proteins to modify ligand distribution and allowing experiments that may give insight into mechanisms regulating morphogen gradients.

利用共聚焦分析<em&gt;非洲爪蟾</em&gt;调查的Wnt和Shh形态发生素梯度的调节剂

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the ...

Stem cell-like Xenopus Embryonic Explants to Study Early Neural Developmental Features In Vitro and In Vivo

Understanding the genetic programs underlying neural development is an important goal of developmental and stem cell biology. In the amphibian blastula, cells from the roof of the blastocoel are pluripotent. These cells can be isolated, and programmed to generate various tissues through manipulation of genes expression or induction by morphogens. In this manuscript protocols are described for the use of Xenopus laevis blastocoel roof explants as an assay system to investigate key in vivo and in vitro features of early neural development. These protocols allow the investigation of fate acquisition, cell migration behaviors, and cell autonomous and non-autonomous properties. The blastocoel roof explants can be cultured in a serum-free defined medium and grafted into host embryos. This transplantation into an embryo allows the investigation of the long-term lineage commitment, the inductive properties, and the behavior of transplanted cells in vivo. These assays can be exploited to investigate molecular mechanisms, cellular processes and gene regulatory networks underlying neural development. In the context of regenerative medicine, these assays provide a means to generate neural-derived cell types in vitro that could be used in drug screening.

Stem cell-like Xenopus Embryonic Explants to Study Early Neural Developmental Features In Vitro and In Vivo

In Xenopus embryos, cells from the roof of the blastocoel are pluripotent and can be programmed to generate various tissues. Here, we describe protocols to use amphibian blastocoel roof explants as an assay system to investigate key in vivo and in vitro features of early neural development.

干细胞样<em&gt;爪</em&gt;胚胎外植体，研究早期神经发育特点<em&gt;体外</em&gt;和<em&gt;在体内</em

Understanding the genetic programs underlying neural development is an important goal of developmental and stem cell biology. In the amphibian blastula, ...

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global DNA methylation level of chondrocytes is considered to be a suitable biomarker for the loss of the chondrocyte phenotype. However, results based on different experimental methods can be inconsistent. Therefore, it is important to establish a precise, simple, and rapid method to quantify global DNA methylation levels during chondrocyte dedifferentiation.
Current genome-wide methylation analysis techniques largely rely on bisulfite genomic sequencing. Due to DNA degradation during bisulfite conversion, these methods typically require a large sample volume. Other methods used to quantify global DNA methylation levels include high-performance liquid chromatography (HPLC). However, HPLC requires complete digestion of genomic DNA. Additionally, the prohibitively high cost of HPLC instruments limits HPLC&#39;s wider application.
In this study, genomic DNA (gDNA) was extracted from human chondrocytes cultured with varying number of passages. The gDNA methylation level was detected using a methylation-specific dot blot assay. In this dot blot approach, a gDNA mixture containing the methylated DNA to be detected was spotted directly onto an N+ membrane as a dot inside a previously drawn circular template pattern. Compared with other gel electrophoresis-based blotting approaches and other complex blotting procedures, the dot blot method saves significant time. In addition, dot blots can detect overall DNA methylation level using a commercially available 5-mC antibody. We found that the DNA methylation level differed between the monolayer subcultures, and therefore could play a key role in chondrocyte dedifferentiation. The 5-mC dot blot is a reliable, simple, and rapid method to detect the general DNA methylation level to evaluate chondrocyte phenotype.

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

We present a method to quantify DNA methylation based on the 5-methylcytosine (5-mC) dot blot. We determined the 5-mC levels during chondrocyte dedifferentiation. This simple technique could be used to quickly determine the chondrocyte phenotype in ACI treatment.

5-mC点印迹测定定量软骨细胞去分化的DNA甲基化水平<em&gt;体外</em

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global ...

Precise Cellular Ablation Approach for Modeling Acute Kidney Injury in Developing Zebrafish

Acute Kidney Injury (AKI) is a common medical condition with a high mortality rate. With the repair abilities of the kidney, it is possible to restore adequate kidney function after supportive treatment. However, a better understanding of how nephron cell death and repair occur on the cellular level is required to minimize cell death and to enhance the regenerative process. The zebrafish pronephros is a good model system to accomplish this goal because it contains anatomical segments that are similar to the mammalian nephron. Previously, the most common model used to study kidney injury in fish was the pharmacological gentamicin model. However, this model does not allow for precise spatiotemporal control of injury, and hence it is difficult to study cellular and molecular processes involved in kidney repair. To overcome this limitation, this work presents a method through which, in contrast to the gentamicin approach, a specific Green Fuorescent Protein (GFP)-expressing nephron segment can be photoablated using a violet laser light (405 nm). This novel model of AKI provides many advantages that other methods of epithelial injury lack. Its main advantages are the ability to &#34;dial&#34; the level of injury and the precise spatiotemporal control in the robust in vivo animal model. This new method has the potential to significantly advance the level of understanding of kidney injury and repair mechanisms.

This work presents a new in vivo model of segmental kidney injury using kidney GFP transgenic zebrafish. The model allows for the induction of the targeted ablation of kidney epithelial cells to show the cellular mechanisms of nephron injury and repair.

精确的细胞消融方法建模发展中的斑马鱼急性肾损伤

Acute Kidney Injury (AKI) is a common medical condition with a high mortality rate. With the repair abilities of the kidney, it is possible to restore ...

Generation of Genetically Modified Mice through the Microinjection of Oocytes

The use of genetically modified mice has significantly contributed to studies on both physiological and pathological in vivo processes. The pronuclear injection of DNA expression constructs into fertilized oocytes remains the most commonly used technique to generate transgenic mice for overexpression. With the introduction of CRISPR technology for gene targeting, pronuclear injection into fertilized oocytes has been extended to the generation of both knockout and knockin mice. This work describes the preparation of DNA for injection and the generation of CRISPR guides for gene targeting, with a particular emphasis on quality control. The genotyping procedures required for the identification of potential founders are critical. Innovative genotyping strategies that take advantage of the "multiplexing" capabilities of CRISPR are presented herein. Surgical procedures are also outlined. Together, the steps of the protocol will allow for the generation of genetically modified mice and for the subsequent establishment of mouse colonies for a plethora of research fields, including immunology, neuroscience, cancer, physiology, development, and others.

The microinjection of mouse oocytes is commonly used for both classic transgenesis (i.e., the random integration of transgenes) and CRISPR-mediated gene targeting. This protocol reviews the latest developments in microinjection, with a particular emphasis on quality control and genotyping strategies.

通过显微注射卵母细胞生成转基因小鼠

The use of genetically modified mice has significantly contributed to studies on both physiological and pathological in vivo processes. The pronuclear ...

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C (UV-C) Damage

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational health hazard. Here, we demonstrate the exposure of primary stem cells from the mouse ocular surface to UV-C radiation. Reactive oxygen species (ROS) formation is the readout of the extent of oxidative stress/damage. In an experimental in vitro setting, it is also essential to assess the percentage of dead cells generated due to oxidative stress. In this article, we will demonstrate the 2&#39;,7&#39;-Dichlorofluoresceindiacetate (DCFDA) staining of UV-C exposed mouse primary ocular surface stem cells and their quantification based on the fluorescent images of DCFDA staining. DCFDA staining directly corresponds to ROS generation. We also demonstrate the quantification of dead and live cells by simultaneous staining with propidium iodide (PI) and Hoechst 3332 respectively and the percentage of DCFDA (ROS positive) and PI positive cells.

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C UV-C Damage

This protocol demonstrates the simultaneous detection of reactive oxygen species (ROS), live cells, and dead cells in live primary cultures from mouse ocular surface cells. 2&#39;,7&#39;-Dichlorofluoresceindiacetate, propidium iodide, and Hoechst staining are used to assess the ROS, dead cells, and live cells, respectively, followed by imaging and analysis.

评估原小鼠眼部表面细胞/干细胞对紫外线-C （UV-C） 损伤的反应

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational ...

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the development of neuronal connectivity. During establishment of the retino-tectal projection, optic axons extend from the eye and navigate through distinct regions of the brain to reach their target tissue, the optic tectum. Once optic axons enter the tectum, they elaborate terminal arbors that function to increase the number of synaptic connections they can make with target interneurons in the tectum. Here, we describe a method to express DNA encoding green fluorescent protein (GFP), and gain- and loss-of-function gene constructs, in optic neurons (retinal ganglion cells) in Xenopus embryos. We explain how to microinject a combined DNA/lipofection reagent into eyebuds of one day old embryos such that exogenous genes are expressed in single or small numbers of optic neurons. By tagging genes with GFP or co-injecting with a GFP plasmid, terminal axonal arbors of individual optic neurons with altered molecular signaling can be imaged directly in brains of intact, living Xenopus tadpoles several days later, and their morphology can be quantified. This protocol allows for determination of cell-autonomous molecular mechanisms that underlie the development of optic axon arborization in vivo.

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

This protocol aims to demonstrate how to microinject a DNA/DOTAP mixture into eyebuds of one day old Xenopus laevis embryos, and how to image and reconstruct individual green fluorescent protein (GFP) expressing optic axonal arbors in tectal midbrains of intact, living Xenopus tadpoles.

将DNA微注射到异种胚胎的眼蕾中，以及GFP表达光学轴状轴向轴向的成像，活的Xenopus大白鼠

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the ...

Whole-Mount In Situ Hybridization in Zebrafish Embryos and Tube Formation Assay in iPSC-ECs to Study the Role of Endoglin in Vascular Development

Vascular development is determined by the sequential expression of specific genes, which can be studied by performing in situ hybridization assays in zebrafish during different developmental stages. To investigate the role of endoglin(eng) in vessel formation during the development of hereditary hemorrhagic telangiectasia&#160;(HHT), morpholino-mediated targeted knockdown of eng in zebrafish are used to study its temporal expression and associated functions. Here, whole-mount in situ RNA hybridization (WISH) is employed for the analysis of eng and its downstream genes in zebrafish embryos. Also, tube formation assays are performed in HHT patient-derived induced pluripotent stem cell-differentiated&#160;endothelial cells (iPSC-ECs; with eng mutations). A specific signal amplifying system using the whole amount In Situ Hybridization &#8211; WISH provides higher resolution and lower background results compared to traditional methods. To obtain a better signal, the post-fixation time is adjusted to 30 min after probe hybridization. Because fluorescence staining is not sensitive in zebrafish embryos, it is replaced with diaminobezidine (DAB) staining here. In this protocol, HHT&#160;patient-derived iPSC lines containing an eng mutation are differentiated into endothelial cells. After coating a plate with basement membrane matrix for 30 min at 37 &#176;C, iPSC-ECs are seeded as a monolayer into wells and kept at 37 &#176;C for 3 h. Then, the tube length and number of branches are calculated using microscopic images. Thus, with this improved WISH protocol, it is shown that reduced eng expression affects endothelial progenitor formation in zebrafish embryos. This is further confirmed by tube formation assays using iPSC-ECs derived from a patient with HHT. These assays confirm the role for eng in early vascular development.

Presented here is a protocol for whole-mount in situ RNA hybridization analysis in zebrafish and tube formation assay in patient-derived induced pluripotent stem cell-derived endothelial cells to study the role of endoglin in vascular formation.

斑马鱼胚胎全山原位杂交和管状测定在iPSC-ECs中研究恩多林在血管发育中的作用

Vascular development is determined by the sequential expression of specific genes, which can be studied by performing in situ hybridization assays in ...

Isolation, Culture, and Adipogenic Induction of Neural Crest Original Adipose-Derived Stem Cells from Periaortic Adipose Tissue

An excessive amount of adipose tissue surrounding the blood vessels (perivascular adipose tissue, also known as PVAT) is associated with a high risk of cardiovascular disease. ADSCs derived from different adipose tissues show distinct features, and those from the PVAT have not been well characterized. In a recent study, we reported that some ADSCs in the periaortic arch adipose tissue (PAAT) descend from the neural crest cells (NCCs), a transient population of migratory cells originating from the ectoderm.
In this paper, we describe a protocol for isolating red fluorescent protein (RFP)-labeled NCCs from the PAAT of Wnt-1 Cre+/-;Rosa26RFP/+ mice and inducing their adipogenic differentiation in vitro. Briefly, the stromal vascular fraction (SVF) is enzymatically dissociated from the PAAT, and the RFP+ neural crest derived ADSCs (NCADSCs) are isolated by fluorescence activated cell sorting (FACS). The NCADSCs differentiate into both brown and white adipocytes, can be cryopreserved, and retain their adipogenic potential for ~3&#8211;5 passages. Our protocol can generate abundant ADSCs from the PVAT for modeling PVAT adipogenesis or lipogenesis in vitro. Thus, these NCADSCs can provide a valuable system for studying the molecular switches involved in PVAT differentiation.

We present a protocol for the isolation, culture, and adipogenic induction of neural crest derived adipose-derived stem cells (NCADSCs) from the periaortic adipose tissue of Wnt-1 Cre+/-;Rosa26RFP/+ mice. The NCADSCs can be an easily accessible source of ADSCs for modeling adipogenesis or lipogenesis in vitro.

神经冠状原脂肪衍生干细胞的分离、培养和异位诱导，来自围阴脂肪组织

An excessive amount of adipose tissue surrounding the blood vessels (perivascular adipose tissue, also known as PVAT) is associated with a high risk of ...