We appreciate and would like to thank the Howard Hughes Medical Institute for the HHMI Professor award to U.B. which made this project possible. We thank the college at the University of California, Los Angeles for providing facilities and teaching infrastructure support for this work. The work was also supported with funding from Midwestern University and a generous donation from the Charity Fidelity Gift Fund. We thank John VandenBrooks for comments on the manuscript and Krista Pearman for her technical assistance.

This procedure is a 2 day procedure.
Day 1 (2 hr + dissecting time)
1. Pupal Eye Disc Dissection
<ol>
	<li>Select a pupa for dissection. 
	NOTE: The age of the pupa to be dissected will be determined by the experimental needs. However, if examining cell morphology, this is frequently done at 42 hr after puparium formation (APF) at 25 &#176;C, which is the age of the pupae shown in the video. Collect white pupae (considered 0 hr APF) with a wetted paintbrush and arr...

<ol>
	<li>Ready, D. F., Hanson, T. E., Benzer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+Drosophila+retina,+a+neurocrystalline+lattice.">Development of the Drosophila retina, a neurocrystalline lattice.</a> Dev Biol. 53 (2), 217-240 (1976).</li><li>Wolff, T., Ready, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+beginning+of+pattern+formation+in+the+Drosophila+compound+eye:+the+morphogenetic+furrow+and+the+second+mitotic+wave.">The beginning of pattern formation in the Drosophila compound eye: the morphogenetic furrow and the second mitotic wave.</a> Development. 113 (3), 841-850 (1991).</li><li>Carthew, R. W. <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+eye.">Pattern formation in the Drosophila eye.</a> Curr Opin Genet Dev. 17 (4), 309-313 (2007).</li><li>Bao, S., Cagan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preferential+adhesion+mediated+by+Hibris+and+Roughest+regulates+morphogenesis+and+patterning+in+the+Drosophila+eye.">Preferential adhesion mediated by Hibris and Roughest regulates morphogenesis and patterning in the Drosophila eye.</a> Dev cell. 8 (6), 925-935 (2005).</li><li>Grzeschik, N. A., Knust, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IrreC/rst-mediated+cell+sorting+during+Drosophila+pupal+eye+development+depends+on+proper+localisation+of+DE-cadherin.">IrreC/rst-mediated cell sorting during Drosophila pupal eye development depends on proper localisation of DE-cadherin.</a> Development. 132 (9), 2035-2045 (2005).</li><li>Sprecher, S. G., Desplan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switch+of+rhodopsin+expression+in+terminally+differentiated+Drosophila+sensory+neurons.">Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons.</a> Nature. 454 (7203), 533-537 (2008).</li><li>Zuker, C. S., Cowman, A. F., Rubin, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+structure+of+a+rhodopsin+gene+from+D.+melanogaster.">Isolation and structure of a rhodopsin gene from D. melanogaster.</a> Cell. 40 (4), 851-858 (1985).</li><li>Voas, M. G., Rebay, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signal+integration+during+development:+insights+from+the+Drosophila+eye.">Signal integration during development: insights from the Drosophila eye.</a> Dev Dyn. 229 (1), 162-175 (2004).</li><li>Hsiao, H. Y., 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=Dissection+and+immunohistochemistry+of+larval,+pupal+and+adult+Drosophila+retinas.">Dissection and immunohistochemistry of larval, pupal and adult Drosophila retinas.</a> J Vis Exp. , 4347 (2012).</li><li>Call, G. B., 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=Genomewide+clonal+analysis+of+lethal+mutations+in+the+Drosophila+melanogaster+eye:+comparison+of+the+X+chromosome+and+autosomes.">Genomewide clonal analysis of lethal mutations in the Drosophila melanogaster eye: comparison of the X chromosome and autosomes.</a> Genetics. 177 (2), 689-697 (2007).</li><li>Chen, J., 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=Discovery-based+science+education:+functional+genomic+dissection+in+Drosophila+by+undergraduate+researchers.">Discovery-based science education: functional genomic dissection in Drosophila by undergraduate researchers.</a> PLoS Biol. 3 (2), 59 (2005).</li><li>Wolff, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissection+techniques+for+pupal+and+larval+Drosophila+eyes.">Dissection techniques for pupal and larval Drosophila eyes.</a> CSH Protoc. 2007, (2007).</li><li>Williamson, W. R., Hiesinger, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+developing+and+adult+Drosophila+brains+and+retinae+for+live+imaging.">Preparation of developing and adult Drosophila brains and retinae for live imaging.</a> J Vis Exp. 37, 1936 (2010).</li><li>Xu, T., Rubin, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+genetic+mosaics+in+developing+and+adult+Drosophila+tissues.">Analysis of genetic mosaics in developing and adult Drosophila tissues.</a> Development. 117 (4), 1223-1237 (1993).</li><li>Duffy, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GAL4+system+in+Drosophila:+a+fly+geneticist's+Swiss+army+knife.">GAL4 system in Drosophila: a fly geneticist's Swiss army knife.</a> Genesis. 34 (1-2), 1-15 (2002).</li></ol>

While it appears that the process is simple and easy to perform, in reality, this technique requires a great deal of practice to master. Routinely, we start students off by learning to dissect and mount third instar eye discs12, which are much easier to work with. This practice helps to develop an appropriate dissection position of the arms, hands and fingers13 so that manipulation of the forceps under the dissecting microscope is stable, easy and experienced. In essence, the practice period shou...

The fields of developmental and cell biology have been greatly impacted by the model organism: Drosophila melanogaster. Within this model, studies of the eye disc have contributed a great deal of knowledge concerning signaling, cell biology and other areas. The late third larval instar eye disc has been studied extensively and is a powerful model to utilize, as it gives a snapshot of a series of developmental periods, each with its own unique signaling molecules and processes, as the morphogenetic furrow progresses across the eye disc8. However, there is a need to further expand our understanding of developmental processes into the pupal phase of development. While there have been studies on the pupal eye disc3-7, our knowledge does not approach the breadth of work that has been performed on the third instar eye disc. This is due, in part, to the greater difficulty in dissecting the pupal eye disc. Therefore, a presentation of the proper method of dissection could greatly expand research in this area.
While there are stages within pupal eye disc development that are easily dissected, particularly around the mid-pupal period, other time periods are much more challenging to dissect. This protocol represents one method for dissecting pupal eye discs that can be universally used for all pupal developmental time frames. This protocol can be used as an alternative to another protocol9 that shows an easier and faster method to dissect eye discs from the midpupal time points. This protocol was originally filmed and developed for training advanced undergraduate students in the UCLA Undergraduate Research Consortium in Functional Genomics (URCFG)10,11 in the technique of pupal eye dissection. Many undergraduate students were able to utilize this video and method to learn this challenging technique.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Phosphate-buffered saline (PBS, pH 7.4)</td>
			<td></td>
			<td></td>
			<td>80g NaCl, 2g&#160; KCl, 14.4g Na2HPO4, 2.4g KH2PO4, Bring volume to 1 l, adjust the pH to 7.4, autoclave or filter sterilize, dilute to 1X PBS with autoclaved ddH2O before using.</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Promega</td>
			<td>H5142</td>
			<td>Caution: Irritant! Wear gloves.</td>
		</tr>
		<tr>
			<td>0.3% PBT</td>
			<td></td>
			<td></td>
			<td>1.5 ml of Triton X-100, 500 ml 1X PBS.</td>
		</tr>
		<tr>
			<td>37% formaldehyde solution</td>
			<td>Fisher Scientific</td>
			<td>F75P1GAL</td>
			<td>Caution: Toxic, probable human carcinogen! Wear gloves.&#160;</td>
		</tr>
		<tr>
			<td>Fix Solution</td>
			<td></td>
			<td></td>
			<td>(&#8776;4% Formaldehyde in PBS) 50 &#956;l of 37% Formaldehyde, 450 &#956;l 1XPBS, make fresh before use</td>
		</tr>
		<tr>
			<td>Normal goat serum</td>
			<td>Rockland antibodies &#38; assays</td>
			<td>B304</td>
			<td>Aliquot in 1 ml volumes and store at -80C</td>
		</tr>
		<tr>
			<td>Block Solution</td>
			<td></td>
			<td></td>
			<td>10% NGS in PBT.&#160; This can be made and stored at 4 &#176;C for a few days prior to use.</td>
		</tr>
		<tr>
			<td>DAPI stock solution</td>
			<td>Life Technologies</td>
			<td>D3571</td>
			<td>For coutnerstaining nuclei. Prepare a 1 mg/ml solution with ddH2O.</td>
		</tr>
		<tr>
			<td>VectaShield Mounting Medium</td>
			<td>Vector Labs</td>
			<td>H-1000</td>
			<td>Mounting medium</td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma</td>
			<td>G5516</td>
			<td>For mounting. Prepare 70% dilution with ddH2O.</td>
		</tr>
		<tr>
			<td colspan="4">Equipment</td>
		</tr>
		<tr>
			<td>Nutating mixer</td>
			<td>VWR</td>
			<td>82007-202</td>
			<td>Used to rock tissue in 3 well glass dish</td>
		</tr>
		<tr>
			<td>SylGard 182 Silicone Elastomer Kit</td>
			<td>Krayden</td>
			<td>NC9897184</td>
			<td>Used to make silicone dissection dish</td>
		</tr>
		<tr>
			<td>Silicone dissecting dish</td>
			<td></td>
			<td></td>
			<td>Mix Sylgard elastomer kit (above) according to directions gently (to avoid bubbles). Pour mixture into Petri dish (any size). Allow SylGard to cure overnight in 37 &#176;C incubator.</td>
		</tr>
		<tr>
			<td>3 well glass dish</td>
			<td>Corning</td>
			<td>7220-85</td>
			<td>The 3 well variety of these are no longer available, this is the 9 well product.</td>
		</tr>
		<tr>
			<td>72 well microwell minitray</td>
			<td>Nunc</td>
			<td>438733</td>
			<td></td>
		</tr>
		<tr>
			<td>Sharp forceps (Dumont #55)</td>
			<td>Fine Science Tools</td>
			<td>11255-20</td>
			<td></td>
		</tr>
		<tr>
			<td><a name="RANGE!A19">Vannas-type Micro Scissors, Straight, 5mm blade</a></td>
			<td>Ted Pella</td>
			<td>1346</td>
			<td></td>
		</tr>
		<tr>
			<td>100 mm Borosilicate glass capillaries</td>
			<td>World Precision Instruments</td>
			<td>1B100-4</td>
			<td>Pull with needle puller to make fine point tip that allows a small stream of PBS to flow.</td>
		</tr>
		<tr>
			<td>Disposable Transfer Pipets, Fine Tip</td>
			<td>Samco Scientific</td>
			<td>231</td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">Tubing dimensions given are inner diameter (ID) x outer diameter (OD) x wall thickness in inches</td>
		</tr>
		<tr>
			<td>PVC tubing (1/8 x 3/16 x 1/32)</td>
			<td>Nalgene</td>
			<td>8000-0010</td>
			<td rowspan="3">Use these with pulled needle to assemble the blower tube as shown in Figure 2.</td>
		</tr>
		<tr>
			<td>Tygon Silicone tubing (3/32 x 5/32 x 1/32)</td>
			<td>Saint Gobain Performance Plastics</td>
			<td>ABW00004</td>
		</tr>
		<tr>
			<td>Tygon Silicone tubing (1/32 x 3/32 x 1/32)</td>
			<td>Saint Gobain Performance Plastics</td>
			<td>ABW00001</td>
		</tr>
	</tbody>
</table>

dissection and mounting of drosophila pupal eye discs

The Drosophila melanogaster eye disc is a powerful system that can be used to study many different biological processes. It contains approximately 800 separate eye units, termed ommatidia1. Each ommatidium contains eight neuronal photoreceptors that develop from undifferentiated cells following the passage of the morphogenetic furrow in the third larval instar2. Following the sequential differentiation of the photoreceptors, non-neuronal cells develop, including cone and pigment cells, along with mechanosensory bristle cells3. Final differentiation processes, including the structured arrangement of all the ommatidial cell types, programmed cell death of undifferentiated cell types and rhodopsin expression, occurs through the pupal phase4-7. This technique focuses on manipulating the pupal eye disc, providing insight and instruction on how to dissect the eye disc during the pupal phase, which is inherently more difficult to perform than the commonly dissected third instar eye disc. This technique also provides details on immunostaining to allow the visualization of various proteins and other cell components.

As an example of the use of this protocol, results illustrating midpupal (42 hrs APF at 25 &#176;C) eye discs immunostained with different antibodies are presented in Figure 2. By using an antibody directed against phosphotyrosine residues, the membrane of the cells can be observed (Figure 2A). This can be used to identify the regular arrangement of ommatidial cells in the pupal eye following the final patterning processes that occur prior to the midpupal stage. Another representative image depicts the n...

Watch this Scientific Journal Video about Dissection and Mounting of Drosophila Pupal Eye Discs at JoVE.com

Dissection and Mounting of Drosophila Pupal Eye Discs

The goal of this technique is to enable researchers to perform dissection, immunostaining and mounting of pupal eye discs from Drosophila melanogaster of any age.

Dissection and Mounting of Drosophila Pupal Eye Discs

The Drosophila melanogaster eye disc is a powerful system that can be used to study many different biological processes.  It contains approximately 800 ...

dissection-and-mounting-of-drosophila-pupal-eye-discs

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Biology

12.0K Views.  University of California at Los Angeles (UCLA). The goal of this technique is to enable researchers to perform dissection, immunostaining and mounting of pupal eye discs from Drosophila melanogaster of any age.