We would like to thank CSIC for the financial support given to this project, to Mariana Di Dom&#233;nico for her technical assistance with confocal microscopy; to Jos&#233; Leonardo B&#225;ez for his manuscript corrections; to Luciano Correa for his dedication to the creation of the video; to Natalia Rosano for lending her voice for the video and the Bloomington Drosophila Stock Center for providing the stocks used in this study. The Apa1 monoclonal anti-Ptc developed by Isabel Guerrero was obtained from the Developmental Studies Hybridoma Bank (DSHB) under the auspices of the NICHD and maintained by The University of Iowa, Department of Biological Sciences, Iowa City, IA 52242.

Day 1
1. Collection and culturing pupae.
<ol>
	<li>Remove 0 h after puparium formation (APF) or prepupae using a wet paintbrush from cultured vials and place them in new vials to almost complete the development period (see 2.1 and 2.2). 
	Note: A healthy population of flies should be maintained using standard culturing protocols. After three or four days in which the eggs are laid, the adults can be removed from vials to allow an optimal development of the individuals. They are maintained at a constant temperature until the third instar larvae initiate pupation. The larval/pupal transition is marked by the formation of the prepupa&#160;considered the 0 h APF. The prepupa is an immobile white larva that has an oblong, round shape with protruding anterior spiracles.</li>
</ol>
Day 2
2. Transfer, dissection and fixation.
<ol>
	<li>Transfer the pupae (2 h before the development time is complete) with a paintbrush, to the microscope slide with double-sided tape adhered to it. Position the pupae to form a row with dorsal sides up and cephalic ends facing the same direction.</li>
	<li>Return the microscope slide to constant temperature and allow the pupae to complete the appropriate developmental time (i.e. 24-30 h APF). 
	Note: The microscope slide with the double-sided tape will be a transitory dissection platform to remove the pupal case (see below). The time lapse on the microscope slide (outside the vial) helps to dry the pupal case making it easily breakable with forceps.</li>
	<li>Remove the operculum from the pupal case using forceps.</li>
	<li>Break the case with forceps (as shown in the video) making a line along the side of the pupa to the caudal end of it. With the appropriate illumination it is possible to detect the internal shape of the pupa making evident a space just above the hinge of the pupal wing. This space serves as a guide to perform the opening without damaging the pupa.</li>
	<li>Remove portions of the case, picking them up by the opened border and carrying them to the opposite side where the double-sided tape will hold them. At the end of the dissection the pupae will be almost &#34;naked&#34;, only a small piece of the case will be covering the posterior tip. 
	Note: The purpose of leaving a small amount of case on the upper caudal end is to ensure a smooth release from the case onto the slide with the double-sided tape. Reasoning behind this action is because if you remove too much of the case you greatly risk damaging the pupa. On the other hand if you remove too little, the pupa will not easily come free of the case.</li>
	<li>Push down (with forceps) the remainder of the case. This movement will raise the anterior end of the pupa, allowing both the head and thorax to stay in a preferential position to adhere and to be transferred in the subsequent step.</li>
	<li>Take a new slide with double-sided tape and invert it on the pupa or pupae row. We recommend performing this approach by observing the movements with the aid of the stereomicroscope to prevent breakage of the pupae.</li>
	<li>Press slightly to make the pupae stick to the tape and gently glide the slide in order to remove the pupae from the rest of the cases. Invert the microscope slide: the pupae will be stuck on the dorsal side at the level of their head / thorax area.</li>
	<li>Cover all the naked pupae with 4% paraformaldehyde and wait 10 min. In our experience, this lapse of time with the fixative helps to change the consistency of the cuticle making it firm, less sticky and easy to handle. 
	Note: To perform the ribonucleic acid (RNA) extraction, substitute paraformaldehyde for phosphate-buffered saline (PBS) made with RNase free water and remove the pupal wings making a cut (with the aid of scissors) near the hinge point of each appendage. Using forceps, transfer the pupal wing to a microcentrifuge tube with 1 mL of guanidinium thiocyanate and phenol reagent. After collecting a total of 50-80 wings, store the microcentrifuge tube at -80 &#176;C until performing the RNA extraction10,11.</li>
	<li>Make a small incision at the hinge region of the wing or near it. Allow the fixative to reach the wing epithelium. Using a pipette (p200) flush fixative over the wing. When flushing replace the contaminated fixate with new. After flushing, keep wing in fixative for 5 min. 
	Note: Although this maneuver helps to clear away the majority of the contaminating tissue, some hemocytes and fat droplets can remain trapped in between the dorsal and ventral epithelial layers of the wing (see Figure 1A).</li>
	<li>Tear with forceps from the cuticle borders (as shown in the video) expanding the hole and enabling the release of the wing epithelium from the cuticle sac. Once the wing tissue is released, leave it in the paraformaldehyde solution to complete 30 min of fixation.</li>
	<li>Transfer the fixed wings to a one 4-welled plastic dish filled with PBST (Triton X-100 0.05%). Store overnight at 4 &#176;C.</li>
</ol>
Day 3
3. Primary antibody incubation.
<ol>
	<li>Permeabilize the tissue incubating the pupal wings in PBST (Triton X-100 0.2%) for 15 min using a rocking platform to facilitate a gentle liquid medium movement. 
	Note: Until mounting&#160;the samples, the steps should be performed using a rocking platform.</li>
	<li>Block the samples using PBSTA (BSA 3%, Triton X-100 0.1%) for 1 h.</li>
	<li>Use the same buffer to dilute the primary antibody (mouse anti-Ptc, 1:100) and incubate the pupal wings overnight at 4 &#176;C.</li>
</ol>
Day 4
4. Secondary antibody incubation.
<ol>
	<li>Wash samples 4 x 10 min each with PBST (Triton X-100 0.05%)</li>
	<li>Incubate with secondary antibody (e.g., anti-mouse conjugated to fluorochrome) diluted to appropriate concentration in PBSTA (BSA 3%, Triton X-100 0.1%) at room temperature in the dark, for 2 h. 
	Note: If it is appropriate, use 4&#39;,6-diamidino-2-phenylindole (DAPI) and/or phalloidin to counterstain the tissue. Add these probes with the secondary antibody taking into account the emission wavelength of the fluorochromes to prevent the overlap of signals.</li>
	<li>Wash samples 4 x 10 min each with PBST (Triton X-100 0.05%)</li>
</ol>
5. Mounting
<ol>
	<li>Prepare a sample slide by placing 4 dots of transparent nail polish on the microscope slide as if they were the vertices of a square. They will be the points where the coverslips will rest, helping to avoid crushing the tissue.</li>
	<li>Place 30 &#181;L of mounting media (glycerol/Tris-HCl 80%) in the center of the square of the dots made with nail polish without touching any of the corners (dots). Take a pipette with a yellow cropped tip, load some mounting media and then draw in several pupal wings.</li>
	<li>Transfer pupal wings to the dot of mounting media on the microscope slide. With the aid of a tip, spread the mounting media and sink the pupal wings to prevent them from floating. The morphology of the tissue will be kept if the wings remain flat when the cover glass is placed on. Before placing the cover glass, remove air bubbles.</li>
	<li>Lower the coverslip onto the samples trying to prevent the generation of air bubbles. This movement can be done with the aid of forceps.</li>
</ol>

<ol>
	<li>Serrano, N., O'Farrell, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limb+morphogenesis:+connections+between+patterning+and+growth.">Limb morphogenesis: connections between patterning and growth.</a> Curr Biol. 7 (3), R186-R195 (1997).</li><li>Blair, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compartments+and+appendage+development+in+Drosophila.">Compartments and appendage development in Drosophila.</a> Bioessays. 17 (4), 299-309 (1995).</li><li>Klein, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wing+disc+development+in+the+fly:+the+early+stages.">Wing disc development in the fly: the early stages.</a> Curr Opin Genet Dev. 11 (4), 470-475 (2001).</li><li>Beira, J. V., Paro, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+legacy+of+Drosophila+imaginal+discs.">The legacy of Drosophila imaginal discs.</a> Chromosoma. 125 (4), 573-592 (2016).</li><li>De Celis, J. F., Diaz-Benjumea, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+basis+for+vein+pattern+variations+in+insect+wings.">Developmental basis for vein pattern variations in insect wings.</a> Int J Dev Biol. 47 (7-8), 653-663 (2003).</li><li>Blair, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wing+vein+patterning+in+Drosophila+and+the+analysis+of+intercellular+signaling.">Wing vein patterning in Drosophila and the analysis of intercellular signaling.</a> Annu Rev Cell Dev Biol. 23, 293-319 (2007).</li><li>Bier, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drawing+lines+in+the+Drosophila+wing:+initiation+of+wing+vein+development.">Drawing lines in the Drosophila wing: initiation of wing vein development.</a> Curr Opin Genet Dev. 10 (4), 393-398 (2000).</li><li>De Celis, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pattern+formation+in+the+Drosophila+wing:+The+development+of+the+veins.">Pattern formation in the Drosophila wing: The development of the veins.</a> Bioessays. 25 (5), 443-451 (2003).</li><li>Classen, A. K., Aigouy, B., Giangrande, A., Eaton, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+Drosophila+pupal+wing+morphogenesis.">Imaging Drosophila pupal wing morphogenesis.</a> Methods Mol Biol. 420, 265-275 (2008).</li><li>Bolatto, C., 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=Spatial+and+temporal+distribution+of+Patched-related+protein+in+the+Drosophila+embryo.">Spatial and temporal distribution of Patched-related protein in the Drosophila embryo.</a> Gene Expr Patterns. 19 (1-2), 120-128 (2015).</li><li>Zuniga, A., 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=Genes+encoding+novel+secreted+and+transmembrane+proteins+are+temporally+and+spatially+regulated+during+Drosophila+melanogaster+embryogenesis.">Genes encoding novel secreted and transmembrane proteins are temporally and spatially regulated during Drosophila melanogaster embryogenesis.</a> BMC Biol. 7, 61 (2009).</li></ol>

The authors have nothing to disclose.

The method of dissection described in this video can be used to prepare high quality samples of Drosophila pupal wings from different development stages for many types of techniques (e.g., immunofluorescence, cDNA synthesis to PCR assays, in vitro wing development). In terms of this method the scientist involved have used 24-30 h APF. However there should be no obstacle within the essential steps in dissection of younger or older pupa. Changes may have to be made to accommodate smaller stage pu...

Drosophila wings are developed from the wing imaginal discs. The primordial of these wing discs are put aside during the embryonic development as small groups of 20-30 imaginal cells that invaginate from the embryonic epithelium. While the larva is growing to the third instar stage, mitosis occurs in the imaginal cells at specific characteristic times raising its numbers (approximately 50000 cells) and forming the wing disc1,2,3,4. As the cells proliferate, they fashion a tubular epithelium, resulting in a self-folding compact spiral. During pupation, the disc epithelium telescopes out to form the two-layered wing and the longitudinal veins start as lacunae between them, which occurs twice during wing developmental5,6.
The arrangement of veins always has an identical pattern;&#160;the ability to easily identify every alteration within the veins formation makes mutations extremely visible (e.g. missing or extra veins, changes in the vein positions, etc.). Interestingly, the phenotype variations are usually the evidence of mutations in known or novel components of signaling pathways that are relevant for wing development. One of the pathways that plays a role in determining the position and maintaining vein and intervein territories is the Hedgehog (Hh) pathway6,7,8.
Given the importance of the pupal wing as a model system, it will be important to obtain good quality samples to work with. In the past, scientists that have published protocols to dissect Drosophila&#160;wings have not given an appropriate guide to attain workable samples. Without the guidance of a researcher one cannot clearly visualize the process. In these alternate dissecting approaches the pupa is split in two, separating the wing from surrounding tissue and repeatedly washed to remove the debris. This kind of approach claims to leave the wing free of contaminates but due to previous experience the process is slower and there is a higher chance of compromising the structure of the fragile wings9.
The procedure described here was developed by the demand to find a fast and efficient method to obtain pupal wing samples suitable to detect specific proteins or transcripts using immunodetection protocols or polymerase chain reaction (PCR) assays. In order to illustrate this, the expression and localization of Patched (Ptc or the canonical receptor of the Hh pathway) is detected in pupal wing samples, providing a protocol that includes relevant details to successfully carry out the complete procedure.

<table border="0" cellpadding="0" cellspacing="0" width="809">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:349px;">Stereomicroscope with cool light illumination</td>
			<td style="width:175px;">Nikon&#160;</td>
			<td style="width:119px;">SMZ1000</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Rocking platform</td>
			<td>Biometra (WT 16)</td>
			<td>042-500</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Microscope slides</td>
			<td>StarFrost</td>
			<td>8037/1</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cover glasses (24 x 32 mm)</td>
			<td>Deltalab</td>
			<td>D102432</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Forceps</td>
			<td>F.S.T</td>
			<td>11252-00</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Scissors</td>
			<td>Lawton</td>
			<td>63-1400</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Multi-well plastic dish</td>
			<td>Thermo Scientific</td>
			<td>144444</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">p100 or p200 pipette</td>
			<td>Finnpipette (Labsystems)</td>
			<td>9400130</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">1X PBS (Dulbecco)</td>
			<td>Gibco</td>
			<td>21600-010</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">4% paraformaldehyde&#160;</td>
			<td>Sigma</td>
			<td>158127</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Triton X-100</td>
			<td>Sigma</td>
			<td>T8787</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">BSA</td>
			<td>Bio Basic INC.</td>
			<td>9048-46-8</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Glycerol</td>
			<td>Mallinckrodt</td>
			<td>5092</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tris</td>
			<td>Amresco</td>
			<td>497</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">TRIzol Reagent</td>
			<td>Ambion</td>
			<td>15596026</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DEPC treated water</td>
			<td>MO.BIO</td>
			<td>17011-200</td>
			<td></td>
		</tr>
		<tr height="57">
			<td height="57" style="height:57px;width:349px;">Alexa Fluor 546 goat anti-mouse IgG (H+L), 2 mg/mL 
			(working dilution 1/800)</td>
			<td style="width:175px;">Invitrogen</td>
			<td style="width:119px;">A11030</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="153">
			<td height="153" style="height:153px;width:349px;">Monoclonal anti-Ptc (Apa-1) 54 &#956;g/mL 
			(working dilution 1/100)</td>
			<td style="width:175px;">Developmental Studies Hybridoma Bank (DSHB)</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">By Isabel Gerrero from DSHB under the auspices of the NICHD and maintained by The University of Iowa, Department of Biological Sciences, Iowa City, IA 52242.&#160;</td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;width:349px;">DAPI, 1 mg/mL 
			(working dilution 1/5000)</td>
			<td style="width:175px;">Invitrogen</td>
			<td style="width:119px;">62248</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="58">
			<td height="58" style="height:58px;width:349px;">Phalloidin conjugated to Alexa 488, 300 U/1.5 mL methanol 
			(1/600 working dilution)</td>
			<td style="width:175px;">Invitrogen</td>
			<td style="width:119px;">A12379</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;width:349px;">Canton S (fly stock)</td>
			<td style="width:175px;">Bloomington Drosophila Stock Center&#160;</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
	</tbody>
</table>

a rapid and efficient method to dissect pupal wings of drosophila suitable for immunodetections or pcr assays

Wing development in Drosophila melanogaster is an ideal model for studying morphogenesis at tissue level. These appendages develop from a group of cells named wing imaginal discs formed during embryonic development. In the larval stages the imaginal discs grow, increasing its number of cells and forming monolayered epithelial&#160;structures. Inside the pupal case, the imaginal discs bud out and fold into bilayers along a line that becomes the future margin of the wing. During this process, the longitudinal primodia veins originate vein cells on the prospective dorsal and ventral surfaces of the wing. During the pupal stage the stripes of vein cells of each surface communicate in order to generate tight tubes; at the same time, the cross-veins begin their formation.
With the help of appropriate molecular markers, it is possible to identify the major elements composing the wing during its development. For this reason, the ability to accurately detect transcripts or proteins in this structure is critical for studying their abundance and localization related to the development process of the wing.
The procedure described here focuses on manipulating pupal wings, providing detailed instructions on how to dissect the wing during the pupal stage. The dissection of pupal tissue is more difficult to perform than their counterparts in third instar larvae. This is why this approach was developed, to obtain rapid and efficient high quality samples. Details of how to immunostain and mount these wing samples, to allow the visualization of proteins or cell components, are provided in the protocol. With little expertise it is possible to collect 8-10 high quality pupal wings in a short amount of time.

The protocol offers a straightforward method for obtaining pupal wing samples that retain the familiar morphology of the wing. From these preparations it is possible to obtain stacks of images that could be projected as 2-D or 3-D, to investigate distribution and/or the enrichment of proteins during the differentiation of the wing. A similar protocol (see the note in 2.9) can be used to collect the large pupal wing sample (involving 50-80 pupal wings) necessary to synthesize complementary...

Watch this Scientific Journal Video about A Rapid and Efficient Method to Dissect Pupal Wings of Drosophila Suitable for Immunodetections or PCR Assays at JoVE.com

A Rapid and Efficient Method to Dissect Pupal Wings of Drosophila Suitable for Immunodetections or PCR Assays

The ability to accurately detect transcripts or proteins in Drosophila tissues is critical for studying their abundance and localization related to the development process. Here is the description of a straightforward procedure to dissect pupal wings. These wings can be used as samples in several techniques (immunohistochemistry, PCR assay, etc.).

A Rapid and Efficient Method to Dissect Pupal Wings of Drosophila Suitable for Immunodetections or PCR Assays

Wing development in Drosophila melanogaster is an ideal model for studying morphogenesis at tissue level. These appendages develop from a group of cells ...

a-rapid-efficient-method-to-dissect-pupal-wings-drosophila-suitable

Universidad San Sebastian

Research

JoVE Journal

Developmental Biology

8.0K Views.  Laboratorio de Biología del Desarrollo. The ability to accurately detect transcripts or proteins in Drosophila tissues is critical for studying their abundance and localization related to the development process. Here is the description of a straightforward procedure to dissect pupal wings. These wings can be used as samples in several techniques (immunohistochemistry, PCR assay, etc.).

Video: A Rapid and Efficient Method to Dissect Pupal Wings of Drosophila Suitable for Immunodetections or PCR Assays

Live-imaging of the Drosophila Pupal Eye

Inherent processes of Drosophila pupal development can shift and distort the eye epithelium in ways that make individual cell behavior difficult to track during live cell imaging. These processes include: retinal rotation, cell growth and organismal movement. Additionally, irregularities in the topology of the epithelium, including subtle bumps and folds often introduced as the pupa is prepared for imaging, make it challenging to acquire in-focus images of more than a few ommatidia in a single focal plane. The workflow outlined here remedies these issues, allowing easy analysis of cellular processes during Drosophila pupal eye development. Appropriately-staged pupae are arranged in an imaging rig that can be easily assembled in most laboratories. Ubiquitin-DE-Cadherin:GFP and GMR-GAL4&#8211;driven UAS-&#945;-catenin:GFP are used to visualize cell boundaries in the eye epithelium 1-3. After deconvolution is applied to fluorescent images captured at multiple focal planes, maximum projection images are generated for each time point and enhanced using image editing software. Alignment algorithms are used to quickly stabilize superfluous motion, making individual cell behavior easier to track.

Live-imaging of the Drosophila Pupal Eye

This protocol presents an efficient method for imaging the live Drosophila pupal eye neuroepithelium. This method compensates for tissue movement and uneven topology, enhances visualization of cell boundaries through the use of multiple GFP-tagged junction proteins, and uses an easily-assembled imaging rig.

Inherent processes of Drosophila pupal development can shift and distort the eye epithelium in ways that make individual cell behavior difficult to track ...

A Quick and Efficient Method for the Purification of Endoderm Cells Generated from Human Embryonic Stem Cells

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell replacement therapies. Terminally differentiated cell types could be used for the treatment of various degenerative diseases. In vitro differentiation of these cells towards tissues of the lung, liver and pancreas requires as a first step the generation of definitive endodermal cells. This step is rate-limiting for further differentiation towards terminally matured cell types such as insulin-producing beta cells, hepatocytes or other endoderm-derived cell types. Cells that are committed towards the endoderm lineage highly express a multitude of transcription factors such as FOXA2, SOX17, HNF1B, members of the GATA family, and the surface receptor CXCR4. However, differentiation protocols are rarely 100% efficient. Here, we describe a method for the purification of a CXCR4+ cell population after differentiation into the DE by using magnetic microbeads. This purification additionally removes cells of unwanted lineages. The gentle purification method is quick and reliable and might be used to improve downstream applications and differentiations.

Here, we describe a method for the purification of differentiated human embryonic stem cells that are committed towards the definitive endoderm for the improvement of downstream applications and further differentiations.

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell ...

An Efficient Method to Obtain Dedifferentiated Fat Cells

Tissue engineering and cell therapy hold great promise clinically. In this regard, multipotent cells, such as mesenchymal stem cells (MSCs), may be used therapeutically, in the near future, to restore function to damaged organs. Nevertheless, several technical issues, including the highly invasive procedure of isolating MSCs and the inefficiency surrounding their amplification, currently hamper the potential clinical use of these therapeutic modalities. Herein, we introduce a highly efficient method for the generation of dedifferentiated fat cells (DFAT), MSC-like cells. Interestingly, DFAT cells can be differentiated into several cell types including adipogenic, osteogenic, and chondrogenic cells. Although other groups have previously presented various methods for generating DFAT cells from mature adipose tissue, our method allows us to produce DFAT cells more efficiently. In this regard, we demonstrate that DFAT culture medium (DCM), supplemented with 20% FBS, is more effective in generating DFAT cells than DMEM, supplemented with 20% FBS. Additionally, the DFAT cells produced by our cell culture method can be redifferentiated into several tissue types. As such, a very interesting and useful model for the study of tissue dedifferentiation is presented.

We have modified the conditions for DFAT cell generation and provide herein information regarding the use of an improved growth medium for the production of these cells.

Tissue engineering and cell therapy hold great promise clinically. In this regard, multipotent cells, such as mesenchymal stem cells (MSCs), may be used ...

Rapid, Directed Differentiation of Retinal Pigment Epithelial Cells from Human Embryonic or Induced Pluripotent Stem Cells

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing a detailed and thorough protocol is to clearly demonstrate each step and to make this readily available to researchers in the field. This protocol results in a homogenous layer of RPE with minimal or no manual dissection needed. The method presented here has been shown to be effective for induced pluripotent stem cells (iPSC) and human embryonic stem cells. Additionally, we describe methods for cryopreservation of intermediate cell banks that allow long-term storage. RPE generated using this protocol might be useful for iPSC disease-in-a-dish modeling or clinical application.

This protocol describes how to produce retinal pigment epithelial cells (RPE) from pluripotent stem cells. The method uses a combination of growth factors and small molecules to direct the differentiation of stem cells into immature RPE in fourteen days and mature, functional RPE after three months.

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing ...

Dissection and Staining of Drosophila Pupal Ovaries

Unlike adult Drosophila ovaries, pupal ovaries are relatively difficult to access and examine due to their small size, translucence, and encasing within a pupal case. The challenge of dissecting pupal ovaries also lies in their physical location within the pupa: the ovaries are surrounded by fat body cells inside the pupal abdomen, and these fat cells must be removed to allow for proper antibody staining. To overcome these challenges, this protocol utilizes customized Pasteur pipets to extract fat body cells from the pupal abdomen. Moreover, a chambered coverglass is used in place of a microcentrifuge tube during the staining process to improve visibility of the pupae. However, despite these and other advantages of the tools used in this protocol, successful execution of these techniques may still involve several days of practice due to the small size of pupal ovaries. The techniques outlined in this protocol could be applied to time course experiments in which ovaries are analyzed at various stages of pupal development.

Dissection and Staining of Drosophila Pupal Ovaries

The Drosophila ovary is an excellent model system for studying stem cell niche development. Though methods for dissecting larval and adult ovaries have been published, pupal ovary dissections require different techniques that have not been published in detail. Here we outline a protocol for dissecting, staining, and mounting pupal ovaries.

Unlike adult Drosophila ovaries, pupal ovaries are relatively difficult to access and examine due to their small size, translucence, and encasing within a ...

A Simplified and Efficient Method to Isolate Primary Human Keratinocytes from Adult Skin Tissue

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical applications. The conventional isolation method of human keratinocytes involves a two-step sequential enzymatic digestion procedure, which has been proven to be inefficient in generating primary cells from adult tissues due to the low cell recovery rate and reduced cell viability. We recently reported an advanced method to isolate human primary epidermal progenitor cells from skin tissues that utilizes the Rho kinase inhibitor Y-27632 in the medium. Compared with the traditional protocol, this new method is simpler, easier, and less time-consuming, and increases epithelial stem cell yield and enhances their stem cell characteristics. Moreover, the new methodology does not require the separation of the epidermis from the dermis, and, therefore, is suitable for isolating cells from different types of adult tissues. This new isolation method overcomes the major shortcomings of conventional methods and is more suitable for producing large numbers of epidermal cells with high potency both for laboratory and for clinical applications. Here, we describe the new method in detail.

Here we present a protocol to efficiently isolate primary human keratinocytes from adult skin tissues. This method simplifies the conventional procedure by using the ROCK Inhibitor Y-27632 in the inoculation medium to spontaneously separate epidermal cells from dermal cells.

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical ...

An Efficient Strategy for Generating Tissue-specific Binary Transcription Systems in Drosophila by Genome Editing

Binary transcription systems are powerful genetic tools widely used for visualizing and manipulating cell fate and gene expression in specific groups of cells or tissues in model organisms. These systems contain two components as separate transgenic lines. A driver line expresses a transcriptional activator under the control of tissue-specific promoters/enhancers, and a reporter/effector line harbors a target gene placed downstream to the binding site of the transcription activator. Animals harboring both components induce tissue-specific transactivation of a target gene expression. Precise spatiotemporal expression of the gene in targeted tissues is critical for unbiased interpretation of cell/gene activity. Therefore, developing a method for generating exclusive cell/tissue-specific driver lines is essential. Here we present a method to generate highly tissue-specific targeted expression system by employing a &#34;Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR-associated&#34; (CRISPR/Cas)-based genome editing technique. In this method, the endonuclease Cas9 is targeted by two chimeric guide RNAs (gRNA) to specific sites in the first coding exon of a gene in the Drosophila genome to create double-strand breaks (DSB). Subsequently, using an exogenous donor plasmid containing the transactivator sequence, the cell-autonomous repair machinery enables homology-directed repair (HDR) of the DSB, resulting in precise deletion and replacement of the exon with the transactivator sequence. The knocked-in transactivator is expressed exclusively in cells where the cis-regulatory elements of the replaced gene are functional. The detailed step-by-step protocol presented here for generating a binary transcriptional driver expressed in Drosophila fgf/branchless-producing epithelial/neuronal cells can be adopted for any gene- or tissue-specific expression.

An Efficient Strategy for Generating Tissue-specific Binary Transcription Systems in Drosophila by Genome Editing

Here, we present a method for generating tissue-specific binary transcription systems in Drosophila by replacing the first coding exon of genes with transcription drivers. The CRISPR/Cas9-based method places a transactivator sequence under the endogenous regulation of a replaced gene, and consequently facilitates transctivator expression exclusively in gene-specific spatiotemporal patterns.

Binary transcription systems are powerful genetic tools widely used for visualizing and manipulating cell fate and gene expression in specific groups of ...

Dissection of the Drosophila Pupal Retina for Immunohistochemistry, Western Analysis, and RNA Isolation

The Drosophila pupal retina provides an excellent model system for the study of morphogenetic processes during development. In this paper, we present a reliable protocol for the dissection of the delicate Drosophila pupal retina. Our surgical approach utilizes readily-available microdissection tools to open pupae and precisely extract eye-brain complexes. These can be fixed, subjected to immunohistochemistry, and retinas then mounted onto microscope slides and imaged if the goal is to detect cellular or subcellular structures. Alternatively, unfixed retinas can be isolated from brain tissue, lysed in appropriate buffers and utilized for protein gel electrophoresis or mRNA extraction (to assess protein or gene expression, respectively). Significant practice and patience may be required to master the microdissection protocol described, but once mastered, the protocol enables relatively quick isolation of mainly undamaged retinas.

Dissection of the Drosophila Pupal Retina for Immunohistochemistry, Western Analysis, and RNA Isolation

This paper presents a surgical method for dissecting Drosophila pupal retinas along with protocols for the processing of tissue for immunohistochemistry, western analysis, and RNA-extraction.&#160;

The Drosophila pupal retina provides an excellent model system for the study of morphogenetic processes during development. In this paper, we present a ...

Thawing, Culturing, and Cryopreserving Drosophila Cell Lines

There are currently over 160 distinct Drosophila cell lines distributed by the Drosophila Genomics Resource Center (DGRC). With genome engineering, the number of novel cell lines is expected to increase. The DGRC aims to familiarize researchers with using Drosophila cell lines as an experimental tool to complement and drive their research agenda. Procedures for working with a variety of Drosophila cell lines with distinct characteristics are provided, including protocols for thawing, culturing, and cryopreserving cell lines. Importantly, this publication demonstrates the best practices required to work with Drosophila cell lines to minimize the risk of contaminations from adventitious microorganisms or from other cell lines. Researchers who become familiar with these procedures will be able to delve into the many applications that use Drosophila cultured cells including biochemistry, cell biology and functional genomics.

Thawing, Culturing, and Cryopreserving Drosophila Cell Lines

Drosophila cell lines are important reagents for both fundamental and biomedical research. This article provides protocols for thawing, subculturing, and the cryopreservation of commonly used Drosophila cell lines to assist researchers in incorporating the use of these reagents in their research.

There are currently over 160 distinct Drosophila cell lines distributed by the Drosophila Genomics Resource Center (DGRC). With genome engineering, the ...

A Direct and Simple Method to Assess Drosophila melanogaster's Viability from Embryo to Adult

In Drosophila melanogaster, viability assays are used to determine the fitness of certain genetic backgrounds. Allelic variations can result in partial or complete loss of viability at different stages of development. Our lab has developed a method to assess viability in Drosophila from embryo to fully mature adult. The method relies on quantifying the number of progeny present at different stages during development, starting with hatched embryos. After embryos have been quantified, additional stages are counted, including L1/L2, pupae, and mature adults. After all stages have been examined, a statistical analysis such as the chi-square test is used to determine if there is a significant difference between the starting number of progeny (hatched embryos) and later stages culminating in the observed number of adults, thus rejecting or accepting the null hypothesis (that the number of hatched embryos will be equal to the number of larvae, pupae, and adults recorded throughout the stages of development). The primary advantage of this assay is its simplicity and accuracy, as it does not require an embryo rinse to transfer them to the food vial, avoiding losses from technical errors. Although the protocol described here does not directly examine L2/L3 larvae, additional steps can be added to account for these. Comparing the number of hatched embryos, L1, pupae, and adults can help determine if viability was compromised during the L2/L3 stages for further studies (the use of colored food helps with visual identification of larvae). Overall, this method can help Drosophila researchers and educators determine when viability is compromised during the fly life cycle. Routine assessment of stocks using this assay can prevent accumulation of secondary mutations that may affect the phenotype of the originally isolated mutant, especially if the original mutations affect fitness. For this reason, our lab maintains multiple copies of each of our Dm ime4 alleles and routinely checks the purity of each stock with this method in addition to other molecular analyses.&#160;

A Direct and Simple Method to Assess Drosophila melanogaster's Viability from Embryo to Adult

This protocol is designed to assess the viability of Drosophila at every developmental stage, from embryo to adult. The method can be used to determine and compare the viability of different genotypes or growth conditions.

In Drosophila melanogaster, viability assays are used to determine the fitness of certain genetic backgrounds. Allelic variations can result in partial or ...