Dissektion och montering av<em> Drosophila</em> PUPP Eye Skivor
Summary
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.
Abstract
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.
Introduction
Områdena utvecklings och cellbiologi har kraftigt påverkats av modellorganism: Drosophila melanogaster. Inom denna modell har studier i ögat skivan bidrog en hel del kunskap om signalering, cellbiologi och andra områden. Den sena tredje larv stadiet öga skiva har studerats ingående och är en kraftfull modell att använda, eftersom det ger en ögonblicksbild av en rad utvecklingsperioder, eftersom morfogenetiska fåran fortskrider över ögat skivan var och en med sina egna unika signalmolekyler och processer, 8. Det finns dock ett behov av att ytterligare utöka vår förståelse av utvecklingsprocesser i PUPP utvecklingsfas. Även om det har gjorts studier på PUPP ögat skivan 3-7, gör vår kunskap inte fram bredden av arbete som har utförts på tredje stadiet ögat skiva. Detta beror delvis på den ökade svårigheten att dissekera PUPP ögat skivan. Därför kan en presentation avkorrekt metod för dissektion skulle kraftigt utöka forskningen inom detta område.
Även om det finns stadier inom PUPP ögonskiv utveckling som lätt dissekeras, särskilt runt mitt PUPP perioden, andra tidsperioder är mycket mer utmanande att dissekera. Detta protokoll utgör en metod för att dissekera PUPP ögon skivor som kan allmänt användas för alla PUPP utvecklingstidsramar. Detta protokoll kan användas som ett alternativ till ett annat protokoll 9 som visar en enklare och snabbare metod för att dissekera ögonskivor från midpupal tidpunkterna. Detta protokoll ursprungligen filmades och utvecklades för att träna avancerade studenter i UCLA Grundutbildning Research Consortium i funktionell genomik (URCFG) 10,11 i tekniken med PUPP ögat dissektion. Många studenter har kunnat utnyttja den här videon och metod för att lära sig denna utmanande teknik.
Protocol
Representative Results
Discussion
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…
Disclosures
The authors have nothing to disclose.
Acknowledgements
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.
Materials
| Phosphate-buffered saline (PBS, pH 7.4) | 80g NaCl, 2g 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. | ||
| Triton X-100 | Promega | H5142 | Caution: Irritant! Wear gloves. |
| 0.3% PBT | 1.5 ml of Triton X-100, 500 ml 1X PBS. | ||
| 37% formaldehyde solution | Fisher Scientific | F75P1GAL | Caution: Toxic, probable human carcinogen! Wear gloves. |
| Fix Solution | (≈4% Formaldehyde in PBS) 50 μl of 37% Formaldehyde, 450 μl 1XPBS, make fresh before use | ||
| Normal goat serum | Rockland antibodies & assays | B304 | Aliquot in 1 ml volumes and store at -80C |
| Block Solution | 10% NGS in PBT. This can be made and stored at 4 °C for a few days prior to use. | ||
| DAPI stock solution | Life Technologies | D3571 | For coutnerstaining nuclei. Prepare a 1 mg/ml solution with ddH2O. |
| VectaShield Mounting Medium | Vector Labs | H-1000 | Mounting medium |
| Glycerol | Sigma | G5516 | For mounting. Prepare 70% dilution with ddH2O. |
| Equipment | |||
| Nutating mixer | VWR | 82007-202 | Used to rock tissue in 3 well glass dish |
| SylGard 182 Silicone Elastomer Kit | Krayden | NC9897184 | Used to make silicone dissection dish |
| Silicone dissecting dish | 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 °C incubator. | ||
| 3 well glass dish | Corning | 7220-85 | The 3 well variety of these are no longer available, this is the 9 well product. |
| 72 well microwell minitray | Nunc | 438733 | |
| Sharp forceps (Dumont #55) | Fine Science Tools | 11255-20 | |
| Vannas-type Micro Scissors, Straight, 5mm blade | Ted Pella | 1346 | |
| 100 mm Borosilicate glass capillaries | World Precision Instruments | 1B100-4 | Pull with needle puller to make fine point tip that allows a small stream of PBS to flow. |
| Disposable Transfer Pipets, Fine Tip | Samco Scientific | 231 | |
| Tubing dimensions given are inner diameter (ID) x outer diameter (OD) x wall thickness in inches | |||
| PVC tubing (1/8 x 3/16 x 1/32) | Nalgene | 8000-0010 | Use these with pulled needle to assemble the blower tube as shown in Figure 2. |
| Tygon Silicone tubing (3/32 x 5/32 x 1/32) | Saint Gobain Performance Plastics | ABW00004 | |
| Tygon Silicone tubing (1/32 x 3/32 x 1/32) | Saint Gobain Performance Plastics | ABW00001 | |
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