High-Resolution Video Tracking of Locomotion in Adult Drosophila Melanogaster

Summary

The study of complex locomotor behavior in Drosophila melanogaster is dependent upon the ability to quantify changes in a given fly's movement. This article demonstrates how to do this using a high-resolution tracking system.

Abstract

Flies provide an important model for studying complex behavior due to the plethora of genetic tools available to researchers in this field. Studying locomotor behavior in Drosophila melanogaster relies on the ability to be able to quantify changes in motion during or in response to a given task. For this reason, a high-resolution video tracking system, such as the one we describe in this paper, is a valuable tool for measuring locomotion in real-time. Our protocol involves the use of an initial air pulse to break the flies momentum, followed by a thirty second filming period in a square chamber. A tracking program is then used to calculate the instantaneous speed of each fly within the chamber in 10 msec increments. Analysis software then compiles this data, and outputs a variety of parameters such as average speed, max speed, time spent in motion, acceleration, etc. This protocol will discuss proper feeding and management of flies for behavioral tasks, handling flies without anesthetization or immobilization, setting up a controlled environment, and running the assay from start to finish.

Protocol

Part 1: Feeding and Management of flies

1. Flies should be grown in bottles containing yeast-free standard media. You will need large numbers of flies, so crosses need to be set up accordingly. Flies should be grown in a 12-hour light:dark cycle at 25ºC.
2. Flies should be collected soon after eclosion (1-3 days). Flies can be worked with at this stage using a carbon dioxide diffuser, and should be sorted into test tubes containing autoclaved or yeast-free media. We use males only, stored 10 to a test tube.
3. Allow at least a day or two after use of carbon dioxide before running the behavioral experiments. We run flies in our behavioral assay 3....

Discussion

In our setup, a moderately strong air pulse transiently stops fly movement. When the air pulse ends, the flies are released from this stationary state and locomote normally, as shown in figure 2. Because this air pulse effectively synchronizes locomotion of the population, we use it to begin the trial so that we can also study the onset of movement following a momentum-breaking stimulus. The assay can, however, be done without an air pulse since locomotor parameters following initiation are unaffected by the air pulse.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Square Chamber	Tool	Machine Shop	N/A	Design from Wolf et al. 20021
Digital Camera	Camera	Sharp	ViewcamZ VL-23
Flowmeter	Tool	Cole-Parmer	SY-32003-12
Light Box	Tool	DNASTAR	Seq-Easy
Charcoal Filter	Tool	Fisher Scientific	09-744-37
DIAS 3.2	Software	Soll technologies	N/A	www.solltechnologies.com