The authors would like to acknowledge Patxi Jaso for the production of the video, PEDECIBA and Agencia Nacional de Investigaci&#243;n e Innovaci&#243;n (ANII) for partial funding.

1.净化染料<ol><li>通过将0.4g污点粉末在10ml蒸馏水制备甲基绿的4％水溶液。调匀，直至完全溶解它。 </li><li>在通风罩，具有至少2份氯仿混合。事先检查管是否氯仿抗性是重要的。 </li><li>调匀，离心1分钟，在2000 XG加速相分离。 </li><li>离心后，上层水相用甲基绿，并用氯仿下​​部的有机相和通常的杂质结晶紫被获得。 </li><li>恢复上相和，直到下阶段似乎完全没有结晶紫重复此步骤。 </li><li>在结束时，上层相回收并用水稀释至2％甲基绿的最终浓度。此原液是稳定在工作台上数月，不需要避光。 </li></ol><ol><li>固定在磷酸盐缓冲盐水（PBS）将胚过夜在4％甲醛（从多聚甲醛）。 注意：这可能需要从几个小时至过夜取决于胚的厚度。在这个例子中，我们固定48小时后受精（HPF）斑马鱼的胚胎过夜。 </li><li>在PBS-T（1％的Triton X-100的PBS）中5分钟洗胚胎三次。升高浓度的洗涤剂permeabilizes角质层。 </li><li>制备1：5,000-1：于PBS-T的万溶液甲基绿的（从2％原液）。洗涤剂的温育过程中的存在对于厚的样品，如斑马鱼的胚胎和幼虫是有用的。 </li><li>孵育至少6小时，溶液中的胚胎在4℃下，用温和的摇摆。再次，胚胎的厚度为保温时间校准参数。 </li><li>洗胚胎3恬西文用PBS 30分钟以除去洗涤剂过量。当结合于DNA甲基绿荧光只有明显，与未结合的分子，因此背景是微不足道的。 </li><li>在山出土的幻灯片或自制室安装液（75％甘油，0.1米的Tris·HCl的pH值为8）。 注意：如果核染色免疫标记后进行，甲基绿可以合并到工作浓度的安装解决方案，而无需冲走。 </li><li>店内冷藏或立即启动成像。用激光扫描共聚焦（或其它荧光）显微镜激发在设定为650-750毫微米考虑到甲基绿色发射在677毫微米达到其最大登记633纳米和发射滤光片进行摄像。 注意：我们提供了甲基绿色发射轮廓的测量数据，也可以装载到采集软件，作为补充材料。 </li></ol> 3.荧光核圣使用甲基绿全鸡胚癌宁<ol><li>孵育受精鸡蛋到感兴趣的阶段。过夜在4％甲醛（从仲甲醛）的PBS固定的胚胎在4℃。在PBS-T 2小时洗胚胎3次。 </li><li>制备1：5,000-1：于PBS-T的万溶液甲基绿的（从2％原液）。孵育在染色液胚胎过夜，在4℃。洗胚胎3次在PBS中，每1小时。安装在腔室用75％甘油，0.1M的Tris，pH为8。 </li></ol> 4.成像荧光标记的细胞核中全安装胚胎<ol><li>通过坚持电气胶带几层在显微镜载玻片，并仔细制备成像室切孔进入它用手术刀以放置胚胎内。这将防止胚胎成像过程中破碎。 </li><li>小心地将胚胎室75％甘油，0.1M的Tris-HCl，pH值为8转移到成像室，并填写顶端到空洞形成气泡。 </li><li>盖上＃0盖玻片避免或消除介质四溢。指甲油密封。 </li><li>获取标本的图像上搭载了633激发滤光片或激光线荧光显微镜。 注：排放过滤器应涵盖677最大发射甲基绿的。 </li></ol>

<ol>
	<li>Klonisch, T., Wark, L., Hombach-Klonisch, S., Mai, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+imaging+in+three+dimensions:+a+unique+tool+in+cancer+research.">Nuclear imaging in three dimensions: a unique tool in cancer research.</a> Annals of anatomy. 192 (5), 292-301 (2010).</li><li>Kapuscinski, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DAPI:+a+DNA-specific+fluorescent+probe.">DAPI: a DNA-specific fluorescent probe.</a> Biotechnic. 70 (5), 220-233 (1995).</li><li>Latt, S. A., Stetten, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+studies+on+33258+Hoechst+and+related+bisbenzimidazole+dyes+useful+for+fluorescent+detection+of+deoxyribonucleic+acid+synthesis.">Spectral studies on 33258 Hoechst and related bisbenzimidazole dyes useful for fluorescent detection of deoxyribonucleic acid synthesis.</a> The journal of histochemistry and cytochemistry. 24 (1), 24-33 (1976).</li><li>Van Hooijdonk, C. A., Glade, C. P., Van Erp, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TO-PRO-3+iodide:+a+novel+HeNe+laser-excitable+DNA+stain+as+an+alternative+for+propidium+iodide+in+multiparameter+flow+cytometry.">TO-PRO-3 iodide: a novel HeNe laser-excitable DNA stain as an alternative for propidium iodide in multiparameter flow cytometry.</a> Cytometry. 17 (2), 185-189 (1994).</li><li>Beumer, T. L., Veenstra, G. J., Hage, W. J., Destr&#233;e, O. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-mount+immunohistochemistry+on+Xenopus+embryos+using+far-red+fluorescent+dyes.">Whole-mount immunohistochemistry on Xenopus embryos using far-red fluorescent dyes.</a> Trends in genetics. 11 (1), 9 (1995).</li><li>Prieto, D., Aparicio, G., Morande, P. E., Zolessi, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+fast,+low+cost,+and+highly+efficient+fluorescent+DNA+labeling+method+using+methyl+green.">A fast, low cost, and highly efficient fluorescent DNA labeling method using methyl green.</a> Histochemistry and cell biology. 142 (3), 335-345 (2014).</li><li>Kim, S. K., Nord&#233;n, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methyl+green.+A+DNA+major-groove+binding+drug.">Methyl green. A DNA major-groove binding drug.</a> FEBS letters. 315 (1), 61-64 (1993).</li><li>Nord&#233;n, B., Tjerneld, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Binding+of+methyl+green+to+deoxyribonucleic+acid+analyzed+by+linear+dichroism.">Binding of methyl green to deoxyribonucleic acid analyzed by linear dichroism.</a> Chemical Physics Letters. 50 (3), 508-512 (1977).</li><li>Lyon, H., Jakobsen, P., Andersen, a. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardized+methyl+green-pyronin+Y+procedures+using+pure+dyes.">Standardized methyl green-pyronin Y procedures using pure dyes.</a> The Histochemical journal. 18 (2-3), 90-94 (1986).</li><li>Amat, F., Keller, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+comprehensive+cell+lineage+reconstructions+in+complex+organisms+using+light-sheet+microscopy.">Towards comprehensive cell lineage reconstructions in complex organisms using light-sheet microscopy.</a> Development, growth &amp; differentiation. 55 (4), 563-578 (2013).</li><li>Chung, K., Deisseroth, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CLARITY+for+mapping+the+nervous+system.">CLARITY for mapping the nervous system.</a> Nature methods. 10 (6), 508-5013 (2013).</li><li>Lenz, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+measurement+in+thick+tissue+layers+by+linear+or+nonlinear+long-wavelength+excitation.">Fluorescence measurement in thick tissue layers by linear or nonlinear long-wavelength excitation.</a> Applied. 38 (16), 3662-3669 (1999).</li></ol>

The authors have nothing to disclose.

The progressive development of microscopy techniques in the last decades, with a particular focus in variations of fluorescent microscopy, have led to the possibility of exploring the dynamics and structure of intact tissue samples, including whole embryos10,11. One major limitation has been, however, the availability of good quality fluorophores that can be used to directly and quickly stain subcellular structures. 
The most frequently used fluorescent DNA stains, such as DAPI or H...

Fluorescent staining of DNA is broadly and routinely used both in biological research and in clinical diagnosis, either for the detailed study of nuclear and chromosomal structure, for counterstaining tissues and cells, or for studying cell cycle parameters1. Although several DNA stains are available, the most widely used have been those excited by UV light and emitting in blue, which fit in the usual three-filter systems used in most conventional epifluorescence microscopes when combined with green and orange-red-emitting fluorophores, such as fluorescent proteins or small molecules attached to antibodies. Among these blue-emitting DNA stains, the most common are DAPI and Hoechst minor groove-binding agents2,3. Nonetheless, the incorporation of a wide variety of laser emission lines and spectral detection in laser scanning microscopes, has allowed researchers to choose for the use of far-red-emitting nuclear stains such as propidium iodide (PI) or TO-PRO 34. An advantage of these stains is that they overcome the problem of autofluorescence found in many cells and tissues, particularly in embryos5, but many of them have different problems such as having wide emission profiles or being very sensitive to photobleaching6.
The Swiss researcher Friedrich Miescher discovered DNA in 1869, extracting it from the nuclei of white blood cells found in pus. He called it nuclein, and showed a few years later that it formed precipitates with the relatively new stain methyl green. Methyl green is composed by three aniline rings, with different degrees of methylation, and has two positive charges that allow it to strongly bind to the major groove of DNA7,8. DNA staining by methyl green was very early shown to be specific, leading to the development by Unna and Pappenheim of a combined stain with pyronin, which specifically labels RNA. Methyl green-pyronin has since then been extensively used in routine histological technique9.
Until recently, very little was known about the fluorescent properties of methyl green. Our previous work, however, has uncovered some of methyl green spectral advantages6 such as its excitation at 633 nm, a convenient Stokes shift, its emission on the near-infrared portion of the electromagnetic spectrum, higher photostability than commercially available DNA stains with similar spectral properties and at a very low cost. This is why we decided to test it for being used as a very high affinity and specific fluorescent label for DNA on embryonic tissues and in whole embryos. Furthermore, until now methyl green nuclear staining was performed at low pH, making it difficult to combine with antibody staining. The goal of the method detailed here is to have a protocol for fluorescent nuclear DNA staining which overcomes the aforementioned inconvenience by performing the staining procedure at physiological pH, thus making it a suitable counterstain for immunolabeling on sections and whole tissues.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Glycerol</td>
			<td>Sigma-Aldrich</td>
			<td>G5516</td>
			<td></td>
		</tr>
		<tr>
			<td>Methyl green</td>
			<td>Dr. G. Gr&#252;bler</td>
			<td></td>
			<td>Also tested Sigma-Aldrich 323829, which is crystal violet-free</td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma-Aldrich</td>
			<td>158127</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser scanning confocal microscopy Leica TCS-SP5</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Phalloidin&#8211;Tetramethylrhodamine B isothiocyanate</td>
			<td>Sigma-Aldrich</td>
			<td> 
			P1951&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>chloroform</td>
			<td>Sigma-Aldrich</td>
			<td>372978</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge 5810 R</td>
			<td>eppendorf</td>
			<td>5811 000.010&#160;&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>microscope slides</td>
			<td>Deltalab</td>
			<td>D100004</td>
			<td></td>
		</tr>
		<tr>
			<td>cover slips</td>
			<td>Esco optics</td>
			<td>R525025</td>
			<td></td>
		</tr>
	</tbody>
</table>

application of the dna-specific stain methyl green in the fluorescent labeling of embryos

Methyl green has long been known as a histological stain with a specific affinity for DNA, although its fluorescent properties have remained unexplored until recently. In this article, we illustrate the method for preparing a methyl green aqueous stock solution, that when diluted can be used as a very convenient fluorescent nuclear label for fixed cells and tissues. Easy procedures to label whole zebrafish and chick embryos are detailed, and examples of images obtained shown. Methyl green is maximally excited by red light, at 633 nm, and emits with a relatively sharp spectrum that peaks at 677 nm. It is very inexpensive, non-toxic, highly stable in solution and very resistant to photobleaching when bound to DNA. Its red emission allows for unaltered high resolution scanning confocal imaging of nuclei in thick specimens. Finally, this methyl green staining protocol is compatible with other cell staining procedures, such as antibody labeling, or actin filaments labeling with fluorophore-conjugated phalloidin.

厚标本核染色。本文描述的协议允许实现深层结构整体胚胎均匀染色。显影透镜晶核形式48 HPF斑马鱼胚胎中均匀标记（ 图1）。 甲基绿DNA染色允许的细胞周期依赖性的形态差异判别如核分裂或凋亡细胞核（ 图2A）的鉴定。在高分辨率亚核结构也是明显所示为斑马鱼胚胎（ 图2B）的表皮细胞核。 甲基绿是耐在高强度照?...

Watch this Scientific Journal Video about Application of the DNA-Specific Stain Methyl Green in the Fluorescent Labeling of Embryos at JoVE.com

Application of the DNA-Specific Stain Methyl Green in the Fluorescent Labeling of Embryos

A method for fluorescent staining of fixed biological material with the specific DNA label methyl green is described. Methyl green is used in a diluted aqueous solution and is very resistant to photobleaching. Its far-red emission allows for deep specimen imaging, making it particularly adequate for whole embryos.

DNA的特定染色甲基绿在胚胎的荧光标记的应用

Methyl green has long been known as a histological stain with a specific affinity for DNA, although its fluorescent properties have remained unexplored ...

application-dna-specific-stain-methyl-green-fluorescent-labeling

Research

JoVE Journal

Developmental Biology

14.0K 次观看.  Institut Pasteur de Montevideo. A method for fluorescent staining of fixed biological material with the specific DNA label methyl green is described. Methyl green is used in a diluted aqueous solution and is very resistant to photobleaching. Its far-red emission allows for deep specimen imaging, making it particularly adequate for whole embryos.

视频: Application of the DNA-Specific Stain Methyl Green in the Fluorescent Labeling of Embryos

Dual Labeling of Neural Crest Cells and Blood Vessels Within Chicken Embryos Using ChickGFP Neural Tube Grafting and Carbocyanine Dye DiI Injection

All developing organs need to be connected to both the nervous system (for sensory and motor control) as well as the vascular system (for gas exchange, fluid and nutrient supply). Consequently both the nervous and vascular systems develop alongside each other and share striking similarities in their branching architecture. Here we report embryonic manipulations that allow us to study the simultaneous development of neural crest-derived nervous tissue (in this case the enteric nervous system), and the vascular system. This is achieved by generating chicken chimeras via transplantation of discrete segments of the neural tube, and associated neural crest, combined with vascular DiI injection in the same embryo. Our method uses transgenic chickGFP embryos for intraspecies grafting, making the transplant technique more powerful than the classical quail-chick interspecies grafting protocol used with great effect since the 1970s. ChickGFP-chick intraspecies grafting facilitates imaging of transplanted cells and their projections in intact tissues, and eliminates any potential bias in cell development linked to species differences. This method takes full advantage of the ease of access of the avian embryo (compared with other vertebrate embryos) to study the co-development of the enteric nervous system and the vascular system.

Dual Labeling of Neural Crest Cells and Blood Vessels Within Chicken Embryos Using ChickGFP Neural Tube Grafting and Carbocyanine Dye DiI Injection

Here we report dual labeling of neural crest cells and blood vessels using chickGFP neural tube intraspecies grafting combined with intra-vascular DiI injection. This experimental technique allows us to simultaneously visualize and study development of the NCC-derived (enteric) nervous system and the vascular system, during organogenesis.

使用小鸡GFP 神经管移植和碳水化合物染料 DiI 注射，在鸡胚胎内对神经囊细胞和血管进行双重标记

All developing organs need to be connected to both the nervous system (for sensory and motor control) as well as the vascular system (for gas exchange, ...

科研

发育生物学

Multi-target Chromogenic Whole-mount In Situ Hybridization for Comparing Gene Expression Domains in Drosophila Embryos

To analyze gene regulatory networks active during embryonic development and organogenesis it is essential to precisely define how the different genes are expressed in spatial relation to each other in situ. Multi-target chromogenic whole-mount in situ hybridization (MC-WISH) greatly facilitates the instant comparison of gene expression patterns, as it allows distinctive visualization of different mRNA species in contrasting colors in the same sample specimen. This provides the possibility to relate gene expression domains topographically to each other with high accuracy and to define unique and overlapping expression sites. In the presented protocol, we describe a MC-WISH procedure for comparing mRNA expression patterns of different genes in Drosophila embryos. Up to three RNA probes, each specific for another gene and labeled by a different hapten, are simultaneously hybridized to the embryo samples and subsequently detected by alkaline phosphatase-based colorimetric immunohistochemistry. The described procedure is detailed here for Drosophila, but works equally well with zebrafish embryos.

Multi-target Chromogenic Whole-mount In Situ Hybridization for Comparing Gene Expression Domains in Drosophila Embryos

We describe a multi-target chromogenic whole-mount in situ hybridization (MC-WISH) procedure in intact Drosophila embryos allowing simultaneous and specific detection of three different mRNA distribution patterns by contrasting color precipitates.

多目标显色全安装<em&gt;原位</em&gt;在比较基因表达域杂交<em&gt;果蝇</em&gt;胚胎

To analyze gene regulatory networks active during embryonic development and organogenesis it is essential to precisely define how the different genes are ...

Affinity Labeling Detection of Endogenous Receptors from Zebrafish Embryos

By combining the powers of Affinity Labeling and Immunoprecipitation (AFLIP), a technique for the detection of low abundance receptors in zebrafish embryos has been implemented. This technique takes advantage of the selectivity and sensitivity conferred by affinity labeling of a given receptor by its ligand with the specificity of the immunoprecipitation. We have used AFLIP to detect the type III TGF-&#946; receptor (TGFBR3), also know as betaglycan, during early zebrafish development. AFLIP was instrumental in validating the efficacy of a TGFBR3 morphant zebrafish phenotype. In the first step, embryo protein extracts are prepared and used to generate 125I-TGF-&#946;2-TGFBR3 complexes that are purified by immunoprecipitation. Later, these complexes are covalently cross-linked and revealed using SDS-PAGE separation and autoradiography detection. This technique requires the availability of a labeled ligand for, and a specific antibody against, the receptor to be detected, and shall be easily adapted to identify any growth factor or cytokine receptor that meets these requirements.

A novel technique for the detection of low abundance endogenous receptors present in zebrafish embryos is described. We have named it AFLIP because it consists of affinity labeling of the receptor by its ligand linked to immunoprecipitation.

从斑马鱼胚胎内源性受体亲和标记检测

By combining the powers of Affinity Labeling and Immunoprecipitation (AFLIP), a technique for the detection of low abundance receptors in zebrafish ...

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced in vivo throughout the rapid developmental period. Multiple processes can be studied including cell proliferation, gene expression, cell migration and morphogenesis. Importantly, the generation of chimeras through transplantations can be easily performed, allowing mosaic labeling and tracking of individual cells under the influence of the host environment. For example, by combining functional gene manipulations of the host embryo (e.g., through morpholino microinjection) and live imaging, the effects of extrinsic, cell nonautonomous signals (provided by the genetically modified environment) on individual transplanted donor cells can be assessed. Here we demonstrate how this approach is used to compare the onset of fluorescent transgene expression as a proxy for the timing of cell fate determination in different genetic host environments.
In this article, we provide the protocol for microinjecting zebrafish embryos to mark donor cells and to cause gene knockdown in host embryos, a description of the transplantation technique used to generate chimeric embryos, and the protocol for preparing and running in vivo time-lapse confocal imaging of multiple embryos. In particular, performing multiposition imaging is crucial when comparing timing of events such as the onset of gene expression. This requires data collection from multiple control and experimental embryos processed simultaneously. Such an approach can easily be extended for studies of extrinsic influences in any organ or tissue of choice accessible to live imaging, provided that transplantations can be targeted easily according to established embryonic fate maps.

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

Live tracking of individual WT retinal progenitors in distinct genetic backgrounds allows for the assessment of the contribution of cell non-autonomous signaling during neurogenesis. Here, a combination of gene knockdown, chimera generation via embryo transplantation and in vivo time-lapse confocal imaging was utilized for this purpose.

在嵌合斑马鱼胚胎的个别视网膜祖细胞转基因表达的体内成像来研究细胞非自治的影响

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

成人果蝇脑内蘑菇体和感光神经元的解剖和荧光染色

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain and protect cellular identities. The conversion of germ cells into specific neurons in the nematode Caenorhabditis elegans (C. elegans) is a powerful tool for performing genetic screens in order to dissect regulatory pathways that safeguard established cell identities. Reprogramming of germ cells to a specific type of neurons termed ASE requires transgenic animals that allow broad over-expression of the Zn-finger transcription factor (TF) CHE-1. Endogenous CHE-1 is expressed exclusively in two head neurons and is required to specify the glutamatergic ASE neurons fate, which can easily be visualized by the gcy-5prom::gfp reporter. A trans gene containing the heat-shock promoter-driven che-1 gene expression construct allows broad mis-expression of CHE-1 in the entire animal upon heat-shock treatment. The combination of RNAi against the chromatin-regulating factor LIN-53 and heat-shock-induced che-1 over-expression leads to reprogramming of germ cell into ASE neuron-like cells. We describe here the specific RNAi procedure and appropriate conditions for heat-shock treatment of transgenic animals in order to successfully induce germ cell to neuron conversion.

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

This protocol describes how to study cellular processes during cell fate conversion in Caenorhabditis elegans in vivo. Using transgenic animals, allowing heat-shock promoter-driven overexpression of the neuron fate-inducing transcription factor CHE-1 and RNAi-mediated depletion of the chromatin-regulating factor LIN-53 germ cell to neuron reprogramming can be observed in vivo.

rna 干扰和热休克诱导转录因子表达在重编程生殖细胞到神经元中的应用C. 线虫

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain ...

Visualizing the Node and Notochordal Plate In Gastrulating Mouse Embryos Using Scanning Electron Microscopy and Whole Mount Immunofluorescence

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is the formation of the transient organizers, the node and notochordal plate, from cells that have passed through the primitive streak. The proper formation of these signaling centers is essential for the development of the body plan and techniques to visualize them are of high interest to mouse developmental biologists. The node and notochordal plate lie on the ventral surface of gastrulating mouse embryos around embryonic day (E) 7.5 of development. The node is a cup-shaped structure whose cells possess a single slender cilium each. The proper subcellular localization and rotation of the cilia in the node pit determines left-right asymmetry. The notochordal plate cells also possess single cilia albeit shorter than those of the node cells. The notochordal plate forms the notochord which acts as an important signaling organizer for somitogenesis and neural patterning. Because the cells of the node and notochordal plate are transiently present on the surface and possess cilia, they can be visualized using scanning electron microscopy (SEM). Among other techniques used to visualize these structures at the cellular level is whole mount immunofluorescence (WMIF) using the antibodies against the proteins that are highly expressed in the node and notochordal plate. In this report, we describe our optimized protocols to perform SEM and WMIF of the node and notochordal plate in developing mouse embryos to help in the assessment of tissue shape and cellular organization in wild-type and gastrulation mutant embryos.

The node and notochordal plate are transient signaling organizers in developing mouse embryos that can be visualized using several techniques. Here, we describe in detail how to perform two of the techniques to study their structure and morphogenesis: 1) scanning electron microscopy (SEM); and 2) whole mount immunofluorescence (WMIF).

用扫描电镜和全贴免疫荧光技术可视化小鼠胚胎中的节点和外型板

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is ...

In Vitro Generation of Somite Derivatives from Human Induced Pluripotent Stem Cells

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give rise to multiple cell types, including the myotome (MYO), sclerotome (SCL), dermatome (D), and syndetome (SYN), which in turn develop into skeletal muscle, axial skeleton, dorsal dermis, and axial tendon/ligament, respectively. Therefore, the generation of SMs and their derivatives from human induced pluripotent stem cells (iPSCs) is critical to obtain pluripotent stem cells (PSCs) for application in regenerative medicine and for disease research in the field of orthopedic surgery. Although the induction protocols for MYO and SCL from PSCs have been previously reported by several researchers, no study has yet demonstrated the induction of SYN and D from iPSCs. Therefore, efficient induction of fully competent SMs remains a major challenge. Here, we recapitulate human SM patterning with human iPSCs in vitro by mimicking the signaling environment during chick/mouse SM development, and report on methods of systematic induction of SM derivatives (MYO, SCL, D, and SYN) from human iPSCs under chemically defined conditions through the presomitic mesoderm (PSM) and SM states. Knowledge regarding chick/mouse&#160;SM development was successfully applied to the induction of SMs with human iPSCs. This method could be a novel tool for studying human somitogenesis and patterning without the use of embryos and for cell-based therapy and disease modeling.

We present here a protocol for the differentiation of human induced pluripotent stem cells into each somite derivative (myotome, sclerotome, dermatome, and syndetome) in chemically defined conditions, which has applications in future disease modeling and cell-based therapies in orthopedic surgery.

人诱导多能干细胞体外生成体细胞衍生物的研究

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give ...

A Multi-Omics Extraction Method for the In-Depth Analysis of Synchronized Cultures of the Green Alga Chlamydomonas reinhardtii

Microalgae have been the focus of research for their applications in the production of high value compounds, food and fuel. Moreover, they are valuable photosynthetic models facilitating the understanding of the basic cellular processes. System wide studies enable comprehensive and in-depth understanding of molecular functions of the organisms. However, multiple independent samples and protocols are required for proteomics, lipidomics and metabolomics studies introducing higher error and variability. A robust high throughput extraction method for the simultaneous extraction of chlorophyll, lipids, metabolites, proteins and starch from a single sample of the green alga Chlamydomonas reinhardtii is presented here. The illustrated experimental setup is for Chlamydomonas cultures synchronized using 12 h/12 h light/dark conditions. Samples were collected over a 24 h cell cycle to demonstrate that the metabolites, lipids and starch data obtained using various analytical platforms are well conformed. Furthermore, protein samples collected using the same extraction protocol were used to conduct detailed proteomics analysis to evaluate their quality and reproducibility. Based on the data, it can be inferred that the illustrated method provides a robust and reproducible approach to advance understanding of various biochemical pathways and their functions with greater confidence for both basic and applied research.

A Multi-Omics Extraction Method for the In-Depth Analysis of Synchronized Cultures of the Green Alga Chlamydomonas reinhardtii

System-wide analysis of multiple biomolecules is crucial to gain functional and mechanistic insights into biological processes. Hereby, an extensive protocol is described for high throughput extraction of lipids, metabolites, proteins and starch from a single sample harvested from synchronized Chlamydomonas culture.

一种对绿色藻原体同步文化进行深入分析的多表率提取方法

Microalgae have been the focus of research for their applications in the production of high value compounds, food and fuel. Moreover, they are valuable ...

An Enhanced Green Fluorescence Protein-based Assay for Studying Neurite Outgrowth in Primary Neurons

Neurite outgrowth is a fundamental event in the formation of the neural circuits during nervous system development. Severe neurite damage and synaptic dysfunction occur in various neurodegenerative diseases and age-related degeneration. Investigation of the mechanisms that regulate neurite outgrowth would not only shed valuable light on brain developmental processes but also on such neurological disorders. Due to the low transfection efficiency, it is currently challenging to study the effect of a specific protein on neurite outgrowth in primary mammalian neurons. Here, we describe a simple method for the investigation of neurite outgrowth by the co-transfection of primary rat cortical neurons with EGFP and a protein of interest (POI). This method allows the identification of POI transfected neurons through the EGFP signal, and thus the effect of the POI on neurite outgrowth can be determined precisely. This EGFP-based assay provides a convenient approach for the investigation of pathways regulating neurite outgrowth.

In this report, we describe a simple protocol for studying neurite outgrowth in embryonic rat cortical neurons by co-transfecting with EGFP and the protein of interest.

增强的绿色荧光蛋白测定，用于研究原神经元的神经质生长

Neurite outgrowth is a fundamental event in the formation of the neural circuits during nervous system development. Severe neurite damage and synaptic ...