Nov 11, 2024

Public workspacePreparing food for Drosophila melanogaster and its relatives

DOI
dx.doi.org/10.17504/protocols.io.j8nlk8poxl5r/v1
  • 1Division of Biological Sciences, University of Montana;
  • 2Department of Biological Sciences, Lehigh University
  • Shropshire Lab
J. Dylan Shropshire
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DOI: dx.doi.org/10.17504/protocols.io.j8nlk8poxl5r/v1
Protocol Citation: Tim Wheeler, Helene Hartman, Brandon S. Cooper, J. Dylan Shropshire 2024. Preparing food for Drosophila melanogaster and its relatives. protocols.io https://dx.doi.org/10.17504/protocols.io.j8nlk8poxl5r/v1
Manuscript citation:
Shropshire JD, Hamant E, Conner WR, Cooper BS. 2022. cifB-transcript levels largely explain cytoplasmic incompatibility variation across divergent Wolbachia. PNAS Nexus. 1(3):pgac099. doi:10.1093/pnasnexus/pgac099.
Hague MTJ, Shropshire JD, Caldwell CN, Statz JP, Stanek KA, Conner WR, Cooper BS. 2022. Temperature effects on cellular host-microbe interactions explain continent-wide endosymbiont prevalence. Curr Biol. 32(4):878. doi:10.1016/j.cub.2021.11.065. Shropshire JD, Hamant E, Cooper BS. 2021. Male age and Wolbachia dynamics: investigating how fast and why bacterial densities and cytoplasmic incompatibility strengths vary. mBio. 12(6):e02998-21. doi:10.1128/mBio.02998-21.
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: September 10, 2024
Last Modified: November 11, 2024
Protocol Integer ID: 107301
Keywords: Drosophila, food, cornmeal, yeast, soy flour, tegosept, propionic acid
Abstract
This protocol outlines the preparation of food for Drosophila melanogaster and related species, using cornmeal, yeast, and soy flour as the primary ingredients. Propionic acid and tegosept are included as preservatives. This recipe yields sufficient food for approximately 700 vials, assuming each is filled with 7-10 mL. This protocol has been successfully employed to maintain nearly 90 Drosophila species. This includes species from both the Sophophora and Drosophila subgenera that diverged about 50 million years ago. Focal examples include D. ananassae, D. auraria, D. baimaii, D. bakoue, D. barbarae, D. bicornuta, D. bockii, D. bocqueti, D. burlai, D. chauvacae, D. diplacantha, D. leontia, D. mauritiana, D. nikananu, D. paulistorum, D. pandora, D. pseudoananassae, D. santomae, D. seguyi, D. simulans, D. sturtevanti, D. subpulchrella, D. suzukii, D. teissieri, D. triauraria, D. tristis, D. tsacasi, D. yakuba, and Zaprionus tsacasi. This protocol is also appropriate for rearing mushroom specialists such as Scaptomyza pallida with the addition of mushrooms.
Materials
Ingredients
  • ReagentCorn Syrup SolidsGenesee ScientificCatalog #62-109
  • ReagentDrosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104
  • ReagentEthanol, 200 ProofKOPTECCatalog #DSP-MD-43
  • ReagentInactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
  • ReagentMalt Extract, LightGenesee ScientificCatalog #62-110
  • ReagentPropionic acidMerck MilliporeSigma (Sigma-Aldrich)Catalog #8.00605
  • ReagentSoy Flour, Research GradeGenesee ScientificCatalog #62-116
  • ReagentTegosept, Fly Food PreservativeGenesee ScientificCatalog #20-259
  • ReagentYellow CornmealGenesee ScientificCatalog #62-101
  • Water, deionized (from diH2O tap)

Other consumables
  • ReagentGlad Pressn SealGenesee ScientificCatalog #88-142 ORReagentDroso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200
  • ReagentNarrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL
  • Paper towels (any)
  • Serological pipette tips, 50 mL, sterile (any)
  • Plastic bags, 5 gallon (any)

Equipment
  • Drill (Makita, 6407)
  • Drosofiller (Genesee Scientific, 59-168)
  • Fridge (any)
  • Graduated cylinder, 1 L (any, autoclaved)
  • Mixer attachment (Jiffy Mixer, Model ES)
  • Precision balance (any)
  • Probe thermometer (any)
  • Serological pipette (Gilson, F110120)
  • Screw-top media bottle, 250 mL (any, autoclaved)
  • Steam kettle (Vulcan, K6ETT)
Protocol materials
ReagentDroso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200
Materials, Step 15
ReagentDrosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104
Materials, Step 1
ReagentSoy Flour, Research GradeGenesee ScientificCatalog #62-116
Materials, Step 1
ReagentYellow CornmealGenesee ScientificCatalog #62-101
Materials, Step 1
ReagentCorn Syrup SolidsGenesee ScientificCatalog #62-109
Materials, Step 1
ReagentMalt Extract, LightGenesee ScientificCatalog #62-110
Materials, Step 1
ReagentTegosept, Fly Food PreservativeGenesee ScientificCatalog #20-259
Materials, Step 2
ReagentEthanol, 200 ProofKOPTECCatalog #DSP-MD-43
Materials, Step 2
ReagentGlad Pressn SealGenesee ScientificCatalog #88-142
Materials, Step 15
ReagentInactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
Materials, Step 1
ReagentNarrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL
Materials, Step 3
ReagentPropionic acidMerck MilliporeSigma (Sigma-Aldrich)Catalog #8.00605
Materials, Step 9
Safety warnings
This protocol involves the use of various chemicals and reagents that require careful handling and strict adherence to safety guidelines to ensure safe laboratory practices. Please review the Material Safety Data Sheets (MSDS) for each reagent before beginning the protocol and take appropriate precautions. All steps should be performed while wearing gloves, a lab coat, and eye protection.
Before start
  1. Sterilize the working surface with 10% bleach.
  2. Sterilize the working surface, Drosofiller, and kettle with 70% ethanol.
Prepare food ingredients
Prepare food ingredients
Weigh the following ingredients using a precision balance and combine in a 1-gallon plastic bag:
  • Amount482 g ReagentYellow CornmealGenesee ScientificCatalog #62-101
  • Amount472 g ReagentCorn Syrup SolidsGenesee ScientificCatalog #62-109
  • Amount304 g ReagentMalt Extract, LightGenesee ScientificCatalog #62-110
  • Amount115 g ReagentInactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
  • Amount66 g ReagentSoy Flour, Research GradeGenesee ScientificCatalog #62-116
  • Amount38 g ReagentDrosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104

Each aliquot can make about 700 vials.
Use immediately or store excess aliquots in a sealed container at room temperature.
Label stored bags with the date and your initials.
700 vial aliquot of fly food in 1-gallon plastic bag.

Mix
Pause
Add Amount25 g of ReagentTegosept, Fly Food PreservativeGenesee ScientificCatalog #20-259 to a Amount250 mL screw-top media bottle.
Fill with ReagentEthanol, 200 ProofKOPTECCatalog #DSP-MD-43 .
Store at room temperature until needed.
Mix
Pause
Cook food
Cook food
Prepare Amount7 trays of Drosophila vials from ReagentNarrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL and spray them with Concentration70 % (v/v) ethanol.
Can replace narrow vials with wide vials or bottles, as desired.
Empty Drosophila vials sprayed lightly with ethanol and covered with plastic until use.

Add Amount7 L of diH2O to the kettle using a graduated cylinder.
Start the mixer.
Ensure the mixer head is fully submerged in the mixture, avoiding contact with the bottom.
Safety information
Position the cord away from the kettle to prevent accidental immersion.

A 6-gallon kettle filled with 7 L of diH2O with the mixer on.


Turn the kettle to the highest heat setting.
As the water begins to boil, reduce the heat to maintain a low boil.
Note
On the Vulcan K6ETT, adjust the dial to the 'L' in 'BOIL' to achieve the desired setting.
Dial turned to the 'L' in 'BOIL' on the Vulcan K6ETT kettle.


Temperature
Mix Amount1 food aliquot thoroughly within the bag and add to the kettle.
Add slowly to prevent forming large clumps.
Kettle after 1 food aliquot is added.

Mix
Cook on a low boil for Duration00:10:00 .
Temperature
Turn off the heater on the kettle while keeping the mixer running.
Add between Amount500 mL and Amount1500 mL of diH2O.
Note
The amount of water added at this step will vary depending on the amount of water evaporated during cooking, which is influenced by room humidity. If the previous batch was unusually dry, add more water. Conversely, if it was excessively wet, add less water.

Mix
Add Amount32.2 mL of ReagentPropionic acidMerck MilliporeSigma (Sigma-Aldrich)Catalog #8.00605 and Amount43.4 mL of tegosept solution into an screw-top media bottle.
Mix
Wait for the food to cool below Temperature63 °C . Add propionic acid and tegosept solution to the kettle.
Checking the temperature of the food with a probe thermometer.

Temperature
Mix for Duration00:02:00 .
Mix
Dispense food
Dispense food
Spray the Drosofiller with Concentration70 % (v/v) ethanol.
Make sure the Drosofiller is securely closed.
Pour the fly food directly into the Drosofiller by tilting the kettle.
Position a tray of vials in the Drosofiller.
Make sure the back of the tray aligns with the back of the Drosofiller.
Dispense the food by pulling the Drosofiller handle to open it.
Each vial should contain Amount7 mL to Amount10 mL of food.
Drosofiller with a tray of files inserted underneath.

Note
The hotter the food and the larger the volume of food in the Drosofiller, the faster the food dispenses.

Seal the vials with ReagentGlad Pressn SealGenesee ScientificCatalog #88-142 ,ReagentDroso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200 , or another closure.
Vials sealed with Glad Press'n Seal.

Individually wrap the trays in Amount5 gallon plastic bags and store them at Temperature4 °C until needed.
Temperature
Clean up
Clean up
Using only diH2O and Concentration70 % (v/v) ethanol, clean the kettle, mixing attachment, drill, and Drosofiller.
Wipe down all surfaces with Concentration70 % (v/v) ethanol.
Mop the immediate area.
Inspect all equipment and surfaces for small flecks of food, as these can attract mites and other hazards.