Measuring Exercise Levels in Drosophila melanogaster Using the Rotating Exercise Quantification System (REQS)

Summary

The Rotating Exercise Quantification System (REQS) can induce exercise in Drosophila melanogaster through rotation while simultaneously measuring the amount of activity performed by the animals. Here, we present a point-by-point protocol detailing how to measure activity levels of animals experiencing rotational exercise treatments using the REQS.

Abstract

Drosophila melanogaster is a new model organism for studies in exercise biology. To date, two main exercise systems, the Power Tower and the Treadwheel have been described. However, a method to measure the amount of additional animal activity induced through the exercise treatment has been lacking. The Rotating Exercise Quantification System (REQS) fills this need, providing a measure of animal activity for animals experiencing rotational exercise. This protocol details how to use the REQS to assess animal activity during rotational exercise and illustrates the type of data that can be generated. Here, we demonstrate how the REQS is used to measure sex- and strain-specific differences in exercise induced activity. The REQS can also be used to evaluate the impact of various other experimental parameters such as age, diet, or population size on exercise induced activity. In addition, it can be used to compare the efficacy of different exercise training protocols. Importantly, it provides an opportunity to standardize exercise treatments between strains, allowing the researcher to achieve equal amounts of activity between groups if needed. Thus, the REQS is a notable new resource for exercise biologists working with the Drosophila model system and complements existing exercise systems.

Introduction

Recently, researchers have begun to use the fruit fly Drosophila melanogaster to study exercise biology. D. melanogaster has been a genetic model system for over 100 years^1,2. However, Drosophila research has made contribution to not just genetics, but also to a variety of other disciplines including neurobiology, behavioral biology, and physiology³. In 2009, the Power Tower, the first exercise machine for Drosophila was described⁴. The Power Tower takes advantage of the animals' negative geotaxis response. When disturbed, Drosophila tend to....

Protocol

The REQS consists of a Drosophila Activity Monitor unit (for source information, please see Table of Materials) mounted on a rotating arm that is controlled by a motor unit (Figure 1). The activity monitor determines how often in a given time span the array of laser beams dissecting the middle of the assay tube is disrupted. For detailed drawings and an in-depth characterization, see our previous publication⁹. While our system uses the LAM25H unit, the REQS can be modified to accommodate other Drosophila Activity Monitor units as well.

1. Testing the Setup of the REQS

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Results

The output from an individual run with the REQS is a data table produced by the DAMSystem308 software, which will be labeled "Monitor1.txt" by default (for an example see Supplemental File 1). An excerpt from such a table is shown in Table 1. Each column contains the data from an individual assay tube, while the rows contain the activity measured in each time interval from the beginning of the experiment (top) to the end (bottom). The first three data poi.......

Discussion

As the representative results illustrate, the REQS is capable of accurately measuring the activity of exercising Drosophila. The REQS is flexible and allows researchers to address a variety of research questions related to exercise biology or exercise interventions. There are two critical steps in the protocol to highlight. First, it is essential to test the setup of the REQS to ensure that data transmission from the REQS to the DAMSystem308 is working properly. If not properly set up, the data cable can become tangled d.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Drosophila Activity Monitor	Trikinetics	LAM25H	REQS component
Telephone Cord Detangler	Uvital	uv20170719	REQS component
Vial closures (flugs)	Genesee Scientific	49-102	Drosophila culture supplies
Vials	Genesee Scientific	32-120	Drosophila culture supplies
Drosophila culture netting	Carolina Biological Supply	173090	Drosophila culture supplies
Cornmeal	Pepsico	43375	Drosophila media
Molasses	Golden Barrel	BLA-GAL	Drosophila media
Agar	Apex Bioresearch	66-103	Drosophila media
Inactive Dry Yeast	Genesee Scientific	62-106	Drosophila media
Tegosept	Apex Bioresearch	20-258	Drosophila media
Propionic acid	Genesee Scientific	20-271	Drosophila media