The monoclonal antibodies (15.3B9, PAX7) developed by ( J. Dodd, T.M Jessell and A. Kawakami) were obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the NICHD and maintained by the University of Iowa, Department of Biological sciences, Iowa. D.P is recipient of Ruth Kirschstein Award 1F32 DA021977-01A1 from the National Institute on Drug Abuse. This work was supported by the Margaret M. Alkek Foundation to RHF.

I. Schematic Overview:
This video demonstrates the different steps in whole mount immunohistochemistry in chick embryo. First, the embryo is fixed in PFA [IHC1]. Then, endogenous peroxidase activity is quenched [IHC2]. The embryo is then incubated in primary antibody [IHC3]. After several washes, the embryo is incubated in secondary antibody [IHC4]; Color reaction is revealed using DAB [IHC5] and antibody staining appears orange [IHC6].
<img src="/files/ftp_upload/old/956_2009_1_26_3/figure 1.png" alt="Figure 1" width="600" height="573" />
Part 1: Fixing the embryos
<ol>
<li>To perform whole mount immunohistochemistry on chick embryos, first open an egg by tapping the shell with forceps and removing pieces of the shell.</li>
<li>Remove the thick albumin with forceps, and tilt the yolk sac with coarse forceps so that the embryo faces upwards.</li>
<li>Using fine scissors, cut a square of yolk sac around the embryo. Remove the embryo from the yolk with a spoon, and place in a dish containing PBS.</li>
<li>Under a dissection microscope, carefully remove the membranes and yolk and the embryo transfer to a fresh dish containing PBS.</li>
<li>Pin the embryo down with forceps and insect pins, and aspirate the PBS. Replace this with 4% PFA in PBS, and allow the embryo to fix 1h at RT. </li>
</ol>
Part 2: Preparing embryos for antibody step
<ol>
<li>To minimize potential microbial contamination, use ddH2O in all following steps.</li>
<li>After the embryo is fixed, aspirate the fixative solution and dispose properly as chemical waste. Fill the dish with PBS.</li>
<li>next, using a microdissection knife, cut a square around embryo to remove extraembryonic membranes. Remove insect pins with forceps.</li>
<li>After the pins have been removed, use a blunt end Pasteur pipette to transfer the embryo to a scintillation vial containing with PBT (PBS pH 7.4, 0.5% Triton X).</li>
<li>Wash the embryo with PBT, 3 times for 10 minutes each.</li>
<li>Remove PBT from the scintillation vial, and replace with PBTx containing 0.3% H2O2 in order to inactivate potential endogenous peroxidase.</li>
<li>Incubate for 2 hr at RT on nutator.</li>
<li>Wash embryo with PBT, 3 times for 10 minutes each, then 3 times for 30 minutes each.</li>
</ol>
Part 3: Antibody incubation
<ol>
<li>To stain the embryo with antibody, start by washing the embryo for one hour in blocking buffer or 1% BSA/1% NGS/PBT (we use NGS because the secondary antibody is raised in goat). Incubate on nutator for one hour at RT.</li>
<li>Dilute the primary antibody 1:1 in blocking buffer, and incubate embryo in this solution for 2 days at 4&deg;C on nutator. Primary antibody dilution factor depends on the choice of primary antibody. Here, we use an antibody from the Developmental Studies Hybridoma Bank, which is provided as supernatent . We dilute it 1:1 in blocking buffer.</li>
<li>next, perform 3 10-minute washes in PBT, followed by 3 1-hour washes in PBT.</li>
<li>After washing, dilute the secondary antibody 1:2500 in blocking buffer (in this case peroxidase conjugated-goat anti-mouse IgG (H+L), and incubate embryo in this solution O/N at 4&deg;C on nutator.</li>
<li>Perform 3 10-minute washes in PBT, followed by 3 1-hour washes in PBT.</li>
</ol>
Part 3: Color reaction
<ol>
<li>To develop the color reaction of the stained embryo, first perform 2 20-minute washes in Tris buffer (100mM Tris HCl, pH 7.4).</li>
<li>Meanwhile dissolve DAB substrate (3,3&rsquo;-diaminobenzidine tetrahydrochloride) in Tris buffer at 500&mu;g/ml under fume hood; keep solution in dark, on ice.</li>
<li>Remove last Tris buffer wash from the vial containing embryo and replace with 5ml DAB solution from step 3.2. Keep in dark on nutator for 20 mn. Dispose of Eppendorf tip in bucket containing a 10% bleach solution in order to decontaminate DAB.</li>
<li>Meanwhile prepare a 0.3% stock H2O2 in dH2O on ice.</li>
<li>Add 50&mu;l stock H2O2 to vial containing embryos in DAB. Keep in dark. After 1-2 minutes, monitor reaction under microscope.</li>
</ol>
Part 4: Embryo processing for photography and histology
<ol>
<li>When color reaction is complete, dispose of DAB in bleach bucket. Replace with 5 ml tap water.</li>
<li>Perform 2 10-minute washes in PBS.</li>
<li>To process for photography and wax sectioning, dehydrate in an ethanol series (25%, 50%, 75% and 100%) for 10 minutes each.</li>
<li>Replace the ethanol with 0.5 - 1 ml cedar wood oil (this will make the embryo translucent). Process for photography in cedar wood oil.</li>
<li>Following photography, return embryo to vial and replace the cedar wood oil with 100% ethanol. Repeat ethanol step.</li>
<li>Replace ethanol with 5% Fast green FCF in 100% ethanol, and incubate for 3 minutes (this step will make embryos visible for histology). Replace Fast green FCF solution with 100% ethanol and process for histology.</li>
</ol>
Representative Results:
<img src="/files/ftp_upload/old/956_2009_1_26_2/figure2.png" alt="Figure 2" width="600" height="498" />
In the examples shown below, embryos are dissected at stages HH 10 (A), 12 (B) and 11 (C); Embryos show expression of PAX 7 in emerging neural crestas well as in somites and neural tube (A,B); In (C), notochord is labelled with 15.3B9 (Not-1) (Antibodies provided by Developmental Studies Hybridoma Bank).

<ol>
	<li>Yamada, T., Placzek, M., Tanaka, H., Dodd, J., Jessell, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+cell+pattern+in+the+developing+nervous+system:+Polarizing+activity+of+the+floor+plate+and+notochord.">Control of cell pattern in the developing nervous system: Polarizing activity of the floor plate and notochord.</a> Cell. 64, 635-647 (1991).</li><li>Streit, A., Stern, C. D., Thery, C., Ireland, G. W., Aparicio, S., Sharpe, M. J., Gherardi, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+role+for+HGF/SF+in+neural+induction+and+its+expression+in+Hensen's+node+during+gastrulation.">A role for HGF/SF in neural induction and its expression in Hensen's node during gastrulation.</a> Development. 121, 813-824 (1995).</li><li>Basch, M., Bronner-Fraser, M., Garcia-Castro, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specification+of+neural+crest+occurs+during+gastrulation+and+requires+Pax7.">Specification of neural crest occurs during gastrulation and requires Pax7.</a> Nature. 441, 218-222 (2006).</li><li>Psychoyos, D., Stern, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Restoration+of+the+organizer+after+radical+ablation+of+Hensen's+node+and+the+anterior+primitive+streak+in+the+chick+embryo.">Restoration of the organizer after radical ablation of Hensen's node and the anterior primitive streak in the chick embryo.</a> Development. 122, 3263-3273 (1996).</li></ol>

This video demonstrates the different steps in performing whole-mount antibody staining in young chick embryos. This protocol is essentially used for the spatial and temporal characterization of novel antibodies in chick 2,3, as well as for the use of known antigenic markers to determine embryonic malformations following insult 4.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Eggs</td>
<td>&nbsp;</td>
<td>Charles River Laboratories</td>
<td>Premium Fertile</td>
<td>Fertilized, HH4 (16 hr)</td>
</tr>
<tr>
<td>Stereomicroscope</td>
<td>Microscope</td>
<td>Leica Microsystems</td>
<td>MZ9.5 or similar</td>
<td>&nbsp;</td>
<tr>
<td>Marsh Automatic Incubator</td>
<td>Other</td>
<td>Lyon</td>
<td>RX</td>
<td>&nbsp;</td>
<tr>
<td>Curved Forceps (1)</td>
<td>Tool</td>
<td>Electron Microscopy Sciences</td>
<td>72991-4C</td>
<td>&nbsp;</td>
<tr>
<td>Forceps (2)</td>
<td>Tool</td>
<td>Fine Science Tools</td>
<td>11002-13</td>
<td>&nbsp;</td>
<tr>
<td>Fine scissors</td>
<td>Tool</td>
<td>Fine Science Tools</td>
<td>14161-10</td>
<td>&nbsp;</td>
<tr>
<td> Plastic dishes</td>
<td>Tool</td>
<td>Falcon</td>
<td>353001</td>
<td>&nbsp;</td>
<tr>
<td>Rubber Bulb</td>
<td>Tool</td>
<td>Electron Microscopy Sciences</td>
<td>70980</td>
<td>&nbsp;</td>
<tr>
<td>Pasteur Capillary Pipette</td>
<td>Tool</td>
<td>Electron Microscopy Sciences</td>
<td>70950-12</td>
<td>round edge under flame</td>
</tr>
<tr>
<td>Microdissecting knife</td>
<td>Tool</td>
<td>Fine Science Tools</td>
<td>10056-12</td>
<td>Use to cut embryo from surrounding membranes following fixation</td>
</tr>
<tr>
<td>Sylgard 184 Silicon Elastomer Curing Agent and Base</td>
<td>Reagent</td>
<td>Dow Corning</td>
<td>0001986475</td>
<td>Mix 1 part Curing Agent, 9 parts Base; set O/N at 37C</td>
</tr>
<tr>
<td>16% PFA</td>
<td>Reagent</td>
<td>Electron Microscopy Sciences</td>
<td>15710</td>
<td>&nbsp;</td>
<tr>
<td>30% H2O2</td>
<td>Reagent</td>
<td>Sigma</td>
<td>H1009</td>
<td>&nbsp;</td>
<tr>
<td>BSA</td>
<td>Reagent</td>
<td>Sigma</td>
<td>A3803</td>
<td>&nbsp;</td>
<tr>
<td>NGS</td>
<td>Reagent</td>
<td>Jackson Immuno</td>
<td>005-000-121</td>
<td>&nbsp;</td>
<tr>
<td>Primary Antibodies</td>
<td>Reagent</td>
<td>Developmental studies Hybridoma Bank</td>
<td>4G11, 15.3B9, PAX7</td>
<td>For these antibodies, investgators used mouse donnors</td>
</tr>
<tr>
<td>Peroxidase conjugated-Goat Anti-Mouse IgG (H+L) </td>
<td>Reagent</td>
<td>Jackson Immuno</td>
<td>115-035-003</td>
<td>&nbsp;</td>
<tr>
<td>3,3&#x2019;-diaminobenzidine tetrahydrochloride</td>
<td>Reagent</td>
<td>Pierce</td>
<td>34001</td>
<td>Store at -20; Allow bottle to warm to RT before use.</td>
</tr>
<tr>
<td>Cedar wood oil</td>
<td>Reagent</td>
<td>Sigma</td>
<td>W522503</td>
<td>&nbsp;</td>
<tr>
<td>Fast green FCF</td>
<td>Reagent</td>
<td>Sigma</td>
<td>F7252</td>
<td>&nbsp;</td>
<tr>
<td>Minuten pins 0.2mm diam</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>26002-20 </td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

method for whole mount antibody staining in chick

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying antibody expression in developing brain, neural tube and somite. This video demonstrates the different steps in whole-mount antibody staining using HRP conjugated secondary antibodies; First, the embryo is dissected from the egg and fixed in paraformaldehyde. Second, endogenous peroxidase is inactivated; The embryo is then exposed to primary antibody. After several washes, the embryo is incubated with secondary antibody conjugated to HRP. Peroxidase activity is revealed using reaction with diaminobenzidine substrate. Finally, the embryo is fixed and processed for photography and sectioning. The advantage of this method over the use of fluorescent antibodies is that embryos can be processed for wax sectioning, thus enabling the study of antigen sites in cross section. This method was originally introduced by Jane Dodd and Tom Jessell 1.

Watch this Scientific Journal Video about Method for Whole Mount Antibody Staining in Chick at JoVE.com

Method for Whole Mount Antibody Staining in Chick

This video demonstrates whole mount immunohistochemistry, a method by which the spatial and temporal expression pattern of an antigen can be visualized in young chick embryos. This method was originally introduced by Jane Dodd and Tom Jessell.

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

method-for-whole-mount-antibody-staining-in-chick

Research

JoVE Journal

Biology

15.7K Aufrufe.  Texas A&M University (TAMU). Dieses Video zeigt whole mount Immunhistochemie, eine Methode, durch die die räumliche und zeitliche Expressionsmuster eines Antigens visualisiert werden bei jungen Hühnerembryonen kann. Diese Methode wurde ursprünglich von Jane Dodd und Tom Jessell eingeführt.

Serie: Method for Whole Mount Antibody Staining in Chick

Double Whole Mount in situ Hybridization of Early Chick Embryos

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  gene expression in brain, neural tube, somite and heart primordia formation. This video demonstrates the different steps in 2-color whole mount in situ hybridization; First, the embryo is dissected from the egg and fixed in paraformaldehyde. Second, the embryo is processed for prehybridization. The embryo is then hybridized with two different probes, one coupled to DIG, and one coupled to FITC.  Following overnight hybridization, the embryo is incubated with DIG coupled antibody. Color reaction for DIG substrate is performed, and the region of interest appears blue. The embryo is then incubated with FITC coupled antibody. The embryo is processed for color reaction with FITC, and the region of interest appears red. Finally, the embryo is fixed and processed for phtograph and sectioning. A troubleshooting guide is also presented.

This video demonstrates 2-color whole mount in situ hybridization, a method by which the spatial and temporal expression pattern of 2 different genes can be visualized in young chick embryos. This method was originally introduced by David Wilkinson, Domingos Henrique, Phil Ingham and David Ish -Horowicz.

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. The protocol is a modified version of the standard in situ hybridization using alkaline phosphatase and substrates such as NBT/BCIP and Fast Red 1,2. This protocol utilizes standard digoxygenin and fluorescein labeled probes along with tyramide signal amplification (TSA) 3. The commercially available TSA kits allow flexible experimental design as fluorescence emission from green to far-red can be used in combination with various nuclear stains, such as propidium iodide, or fluorescence immunohistochemistry for proteins. TSA produces a reactive fluorescent substrate that quickly covalently binds to moieties, typically tyrosine residues, in the immediate vicinity of the labeled antisense riboprobe. The resulting staining patterns are high resolution in that subcellular localization of the mRNA can be observed using laser scanning confocal microscopy 3,4. One can observe nascent transcripts at the chromosomal loci, distinguish nuclear and cytoplasmic staining and visualize other patterns such as cortical localization of mRNA. Studies in Drosophila indicate that roughly 70% of mRNAs exhibit specific patterns of subcellular localization that frequently correlate with the function of the encoded protein 5. When combined with computer-aided reconstruction of 3D confocal datasets, our protocol allows the detailed analysis of mRNA distribution with sub-cellular resolution in whole vertebrate embryos.

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. We include a propidium iodide nuclear counter-stain to highlight tissue organization.

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology.  Here, we present a high-resolution double ...

Using Whole Mount in situ Hybridization to Link Molecular and Organismal Biology

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of specific mRNA transcripts within whole mount specimen. This technique (adapted from Albertson and Yelick, 2005) was used in an upper level undergraduate Comparative Vertebrate Biology laboratory classroom at Syracuse University. The first two thirds of the Comparative Vertebrate Biology lab course gave students the opportunity to study the embryology and gross anatomy of several organisms representing various chordate taxa primarily via traditional dissections and the use of models. The final portion of the course involved an innovative approach to teaching anatomy through observation of vertebrate development employing molecular techniques in which WISH was performed on zebrafish embryos. A heterozygous fibroblast growth factor 8 a (fgf8a) mutant line, ace, was used. Due to Mendelian inheritance, ace intercrosses produced wild type, heterozygous, and homozygous ace/fgf8a mutants in a 1:2:1 ratio. RNA probes with known expression patterns in the midline and in developing anatomical structures such as the heart, somites, tailbud, myotome, and brain were used. WISH was performed using zebrafish at the 13 somite and prim-6 stages, with students performing the staining reaction in class. The study of zebrafish embryos at different stages of development gave students the ability to observe how these anatomical structures changed over ontogeny. In addition, some ace/fgf8a mutants displayed improper heart looping, and defects in somite and brain development. The students in this lab observed the normal development of various organ systems using both external anatomy as well as gene expression patterns. They also identified and described embryos displaying improper anatomical development and gene expression (i.e., putative mutants).
For instructors at institutions that do not already own the necessary equipment or where funds for lab and curricular innovation are limited, the financial cost of the reagents and apparatus may be a factor to consider, as will the time and effort required on the part of the instructor regardless of the setting. Nevertheless, we contend that the use of WISH in this type of classroom laboratory setting can provide an important link between developmental genetics and anatomy. As technology advances and the ability to study organismal development at the molecular level becomes easier, cheaper, and increasingly popular, many evolutionary biologists, ecologists, and physiologists are turning to research strategies in the field of molecular biology. Using WISH in a Comparative Vertebrate Biology laboratory classroom is one example of how molecules and anatomy can converge within a single course. This gives upper level college students the opportunity to practice modern biological research techniques, leading to a more diversified education and the promotion of future interdisciplinary scientific research.

Using Whole Mount in situ Hybridization to Link Molecular and Organismal Biology

Whole mount in situ hybridization (WISH) was used in an upper level undergraduate Comparative Vertebrate Biology course in addition to vertebrate dissections. This gave students the opportunity to study gene expression patterns as well as gross anatomy, linking the study of molecular and organismal biology within one course.

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of ...

Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos

Whole mount in situ hybridization is a very informative approach for defining gene expression patterns in embryos. The in situ hybridization procedures are lengthy and technically demanding with multiple important steps that collectively contribute to the quality of the final result. This protocol describes in detail several key quality control steps for optimizing probe labeling and performance. Overall, our protocol provides a detailed description of the critical steps necessary to reproducibly obtain high quality results. First, we describe the generation of digoxygenin (DIG) labeled RNA probes via in vitro transcription of DNA templates generated by PCR. We describe three critical quality control assays to determine the amount, integrity and specific activity of the DIG-labeled probes. These steps are important for generating a probe of sufficient sensitivity to detect endogenous mRNAs in a whole mouse embryo. In addition, we describe methods for the fixation and storage of E8.5-E11.5 day old mouse embryos for in situ hybridization. Then, we describe detailed methods for limited proteinase K digestion of the rehydrated embryos followed by the details of the hybridization conditions, post-hybridization washes and RNase treatment to remove non-specific probe hybridization. An AP-conjugated antibody is used to visualize the labeled probe and reveal the expression pattern of the endogenous transcript. Representative results are shown from successful experiments and typical suboptimal experiments.

Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos

This whole mount in situ hybridization protocol discusses critical steps that ensure reproducible high quality results for gene expression studies in E8.5-E11.5 day old mouse embryos.

Whole mount in situ hybridization is a very informative approach for defining gene expression patterns in embryos. The in situ hybridization procedures ...

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Assessing the expression pattern of a gene, as well as the subcellular localization properties of its transcribed RNA, are key features for understanding its biological function during development. RNA in situ hybridization (RNA-ISH) is a powerful method used for visualizing RNA distribution properties, be it at the organismal, cellular or subcellular levels 1. RNA-ISH is based on the hybridization of a labeled nucleic acid probe (e.g. antisense RNA, oligonucleotides) complementary to the sequence of an mRNA or a non-coding RNA target of interest 2. As the procedure requires primary sequence information alone to generate sequence-specific probes, it can be universally applied to a broad range of organisms and tissue specimens 3. Indeed, a number of large-scale ISH studies have been implemented to document gene expression and RNA localization dynamics in various model organisms, which has led to the establishment of important community resources 4-11. While a variety of probe labeling and detection strategies have been developed over the years, the combined usage of fluorescently-labeled detection reagents and enzymatic signal amplification steps offer significant enhancements in the sensitivity and resolution of the procedure 12. Here, we describe an optimized fluorescent in situ hybridization method (FISH) employing tyramide signal amplification (TSA) to visualize RNA expression and localization dynamics in staged Drosophila embryos. The procedure is carried out in 96-well PCR plate format, which greatly facilitates the simultaneous processing of large numbers of samples.

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Here we describe a whole-mount fluorescent in situ hybridization (FISH) protocol for determining the expression and localization properties of RNAs expressed during embryogenesis in the fruit fly, Drosophila melanogaster.

Assessing  the expression pattern of a gene, as well as the subcellular localization  properties of its transcribed RNA, are key features for ...

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

Marine elasmobranchs are valued animal models for biomedical and genomic studies as they are the most primitive vertebrates to have adaptive immunity and have unique mechanisms for osmoregulation 1-3. As the most primitive living jawed-vertebrates with paired appendages, elasmobranchs are an evolutionarily important model, especially for studies in evolution and development. Marine elasmobranchs have also been used to study aquatic toxicology and stress physiology in relationship to climate change 4. Thus, development and adaptation of methodologies is needed to facilitate and expand the use of these primitive vertebrates to multiple biological disciplines. Here I present the successful adaptation of RNA whole mount in situ hybridization and histological techniques to study gene expression and cell histology in elasmobranchs.
Monitoring gene expression is a hallmark tool of developmental biologists, and is widely used to investigate developmental processes 5. RNA whole mount in situ hybridization allows for the visualization and localization of specific gene transcripts in tissues of the developing embryo. The expression pattern of a gene's message can provide insight into what developmental processes and cell fate decisions a gene may control. By comparing the expression pattern of a gene at different developmental stages, insight can be gained into how the role of a gene changes during development.
While whole mount in situ's provides a means to localize gene expression to tissue, histological techniques allow for the identification of differentiated cell types and tissues. Histological stains have varied functions. General stains are used to highlight cell morphology, for example hematoxylin and eosin for general staining of nuclei and cytoplasm, respectively. Other stains can highlight specific cell types. For example, the alcian blue stain reported in this paper is a widely used cationic stain to identify mucosaccharides. Staining of the digestive tract with alcian blue can identify the distribution of goblet cells that produce mucosaccharides. Variations in mucosaccharide constituents on short peptides distinguish goblet cells by function within the digestive tract 6. By using RNA whole mount in situ's and histochemical methods concurrently, cell fate decisions can be linked to gene-specific expression.
Although RNA in situ's and histochemistry are widely used by researchers, their adaptation and use in marine elasmobranchs have met limited and varied success. Here I present protocols developed for elasmobranchs and used on a regular basis in my laboratory. Although further modification of the RNA in situ's hybridization method may be needed to adapt to different species, the protocols described here provide a strong starting point for researchers wanting to adapt the use of marine elasmobranchs to their scientific inquiries.

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

By combining methods for RNA whole mount in situ hybridization and histology, gene expression can be linked with cell fate decisions in the developing embryo. These methods have been adapted to marine elasmobranchs and facilitate the use of these animals as model organisms for biomedical, toxicology and comparative studies.

Marine  elasmobranchs are valued animal models for biomedical and genomic studies as  they are the most primitive vertebrates to have adaptive immunity ...

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

To stain C. elegans with antibodies, the relatively impermeable cuticle must be bypassed by chemical or mechanical methods. "Freeze-cracking" is one method used to physically pull the cuticle from nematodes by compressing nematodes between two adherent slides, freezing them, and pulling the slides apart. Freeze-cracking provides a simple and rapid way to gain access to the tissues without chemical treatment and can be used with a variety of fixatives. However, it leads to the loss of many of the specimens and the required compression mechanically distorts the sample. Practice is required to maximize recovery of samples with good morphology. Freeze-cracking can be optimized for specific fixation conditions, recovery of samples, or low non-specific staining, but not for all parameters at once. For antibodies that require very hard fixation conditions and tolerate the chemical treatments needed to chemically permeabilize the cuticle, treatment of intact nematodes in solution may be preferred. If the antibody requires a lighter fix or if the optimum fixation conditions are unknown, freeze-cracking provides a very useful way to rapidly assay the antibody and can yield specific subcellular and cellular localization information for the antigen of interest.

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

"Freeze-cracking," a method for exposing the inner tissues of the nematode C. elegans to antibodies for protein localization, is demonstrated.

To stain C.  elegans with antibodies, the relatively impermeable cuticle must be  bypassed by chemical or mechanical methods.  "Freeze-cracking" is one ...

An Efficient Method for Quantitative, Single-cell Analysis of Chromatin Modification and Nuclear Architecture in Whole-mount Ovules in Arabidopsis

In flowering plants, the somatic-to-reproductive cell fate transition is marked by the specification of spore mother cells (SMCs) in floral organs of the adult plant. The female SMC (megaspore mother cell, MMC) differentiates in the ovule primordium and undergoes meiosis. The selected haploid megaspore then undergoes mitosis to form the multicellular female gametophyte, which will give rise to the gametes, the egg cell and central cell, together with accessory cells. The limited accessibility of the MMC, meiocyte and female gametophyte inside the ovule is technically challenging for cytological and cytogenetic analyses at single cell level. Particularly, direct or indirect immunodetection of cellular or nuclear epitopes is impaired by poor penetration of the reagents inside the plant cell and single-cell imaging is demised by the lack of optical clarity in whole-mount tissues.
Thus, we developed an efficient method to analyze the nuclear organization and chromatin modification at high resolution of single cell in whole-mount embedded Arabidopsis ovules. It is based on dissection and embedding of fixed ovules in a thin layer of acrylamide gel on a microscopic slide. The embedded ovules are subjected to chemical and enzymatic treatments aiming at improving tissue clarity and permeability to the immunostaining reagents. Those treatments preserve cellular and chromatin organization, DNA and protein epitopes. The samples can be used for different downstream cytological analyses, including chromatin immunostaining, fluorescence in situ hybridization (FISH), and DNA staining for heterochromatin analysis. Confocal laser scanning microscopy (CLSM) imaging, with high resolution, followed by 3D reconstruction allows for quantitative measurements at single-cell resolution.

An Efficient Method for Quantitative, Single-cell Analysis of Chromatin Modification and Nuclear Architecture in Whole-mount Ovules in Arabidopsis

We provide here an efficient and reliable protocol for immunostaining, Fluorescence in&#160;situ Hybridization, DNA staining followed by quantitative, high-resolution imaging in whole-mount Arabidopsis thaliana ovules. This method was successfully used to analyze chromatin modifications and nuclear architecture.

In flowering plants, the somatic-to-reproductive cell fate transition is marked by the specification of spore mother cells (SMCs) in floral organs of the ...

Flat Mount Preparation for Observation and Analysis of Zebrafish Embryo Specimens Stained by Whole Mount In situ Hybridization

The zebrafish embryo is now commonly used for basic and biomedical research to investigate the genetic control of developmental processes and to model congenital abnormalities. During the first day of life, the zebrafish embryo progresses through many developmental stages including fertilization, cleavage, gastrulation, segmentation, and the organogenesis of structures such as the kidney, heart, and central nervous system. The anatomy of a young zebrafish embryo presents several challenges for the visualization and analysis of the tissues involved in many of these events because the embryo develops in association with a round yolk mass. Thus, for accurate analysis and imaging of experimental phenotypes in fixed embryonic specimens between the tailbud and 20 somite stage (10 and 19 hours post fertilization (hpf), respectively), such as those stained using whole mount in situ hybridization (WISH), it is often desirable to remove the embryo from the yolk ball and to position it flat on a glass slide. However, performing a flat mount procedure can be tedious. Therefore, successful and efficient flat mount preparation is greatly facilitated through the visual demonstration of the dissection technique, and also helped by using reagents that assist in optimal tissue handling. Here, we provide our WISH protocol for one or two-color detection of gene expression in the zebrafish embryo, and demonstrate how the flat mounting procedure can be performed on this example of a stained fixed specimen. This flat mounting protocol is broadly applicable to the study of many embryonic structures that emerge during early zebrafish development, and can be implemented in conjunction with other staining methods performed on fixed embryo samples.

Flat Mount Preparation for Observation and Analysis of Zebrafish Embryo Specimens Stained by Whole Mount In situ Hybridization

The zebrafish embryo is an excellent model for developmental biology research. During embryogenesis, zebrafish develop with a yolk mass, which presents three-dimensional challenges for sample observation and analysis. This protocol describes how to create two-dimensional flat mount preparations of whole mount in situ (WISH) stained zebrafish embryo specimens.

The zebrafish embryo is now commonly used for basic and biomedical research to investigate the genetic control of developmental processes and to model ...

A Whole Mount In Situ Hybridization Method for the Gastropod Mollusc Lymnaea stagnalis

Whole mount in situ hybridization (WMISH) is a technique that allows for the spatial resolution of nucleic acid molecules (often mRNAs) within a &#39;whole mount&#39; tissue preparation, or developmental stage (such as an embryo or larva) of interest. WMISH is extremely powerful because it can significantly contribute to the functional characterization of complex metazoan genomes, a challenge that is becoming more of a bottleneck with the deluge of next generation sequence data. Despite the conceptual simplicity of the technique much time is often needed to optimize the various parameters inherent to WMISH experiments for novel model systems; subtle differences in the cellular and biochemical properties between tissue types and developmental stages mean that a single WMISH method may not be appropriate for all situations. We have developed a set of WMISH methods for the re-emerging gastropod model Lymnaea stagnalis that generate consistent and clear WMISH signals for a range of genes, and across all developmental stages. These methods include the assignment of larvae of unknown chronological age to an ontogenetic window, the efficient removal of embryos and larvae from their egg capsules, the application of an appropriate Proteinase-K treatment for each ontogenetic window, and hybridization, post-hybridization and immunodetection steps. These methods provide a foundation from which the resulting signal for a given RNA transcript can be further refined with probe specific adjustments (primarily probe concentration and hybridization temperature).

A Whole Mount In Situ Hybridization Method for the Gastropod Mollusc Lymnaea stagnalis

The goal of this protocol is to provide users with a set of methods for the high-throughput decapsulation of Lymnaea stagnalis embryos and larvae in preparation for whole mount in situ hybridization, and for subsequent pre- and post-hybridization treatments.