An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time
October 12th, 2018
Here we present a protocol to automatically determine the locomotor performance of Drosophila at changing temperatures using a programmable temperature-controlled arena that produces fast and accurate temperature changes in time and space.
This method can help us answer key questions about flies'response to temperature changes, such as differences between genotypes, the interaction with other sensory cues, or the function of different temperature receptors. The main advantage of this technique is that it allows for multiple fast and precise temperature changes controlling time and space and in an automated fashion. Begin by placing 20 male and 20 female flies in a rearing bottle containing 45 milliliters of fly food medium, and placing the bottle inside a 25 degree celsius incubator under 12 hour light, 12 hour dark cycles.
After 10 days, anesthetize the newly eclosed flies on carbon dioxide pads for a maximum of four minutes. And use a paintbrush to collect virgin flies in 2.5 by 9.5 centimeter fly rearing vials containing 6.5 milliliters of fresh fly food medium, separated by sex into groups of 20 flies per vial. Then return the vials to the incubator for five to seven days.
To set up a temperature-controlled arena, turn on the arena and open the temperature phases script in the control computer. Verify that the temperature sequence is properly set and check that the duration of each experimental phase is set to 60 seconds. Under the start experimental block section, confirm these settings:the desired number of phases, iterative on/off setup of the indicative red light emitting diodes, two degrees celsius temperature increase per phase, and 16 degrees celsius as the starting temperature.
Next, run the temperature phases script. The software will initialize for five seconds then stop. For temperature behavioral experiments, place a strand of white conductive tape on the top of the copper tiles of the arena, ensuring that all the edges are covered.
Place a heated aluminum ring around the copper tiles and use a clean tissue to wipe the glass cover. Place the cover on the top of the aluminum ring, leaving a gap through which a fly can be blown in and tap an acclimated fly vial two times to force the flies to the bottom of the vial. Using a mouth aspirator, trap one fly and close the vial before putting it back into the incubator.
Blow the fly into the arena through the gap between the glass cover and the aluminum ring and immediately push the glass clover to close the gap. Place a frame of lights around the arena to ensure symmetric illumination and start recording with the video recording program. Then press the space bar of the control computer to begin running the experimental phases.
To track the videos, open the fly steps tracking software and open the configuration file inside the fly tracker folder. Set the location of the videos in video folder, and the names of the videos in video files. Specify the borders of the fly arena in arena settings based on the x/y pixel coordinates of multiple points at the edge of the arena.
Specific the location of the inactive red LEDs in LED settings, based on the x/y pixel coordinates of the location of the center of the LEDs. To check the location of the borders of the fly arena, set debug to true in the arena settings, click save, and run the script in the terminal. A screen capture of the video will appear with a blue square formed by the coordinates inputted in arena settings.
Then change debug in arena settings to false. Click save, and run the screen in the terminal again to begin the tracking process. In a typical temperature behavioral experiment, single flies exposed to 16, 20, or 24 degrees celsius exhibit a higher locomotion at the beginning of the experiment, than after five minutes.
The temperature-controlled arena can also be used to compare fly behavioral responses from different genetic backgrounds to dynamic temperature changes. For example, in this experiment, the speed of all of the tested species increased according to their own response curves as the temperature increased, until reaching a point of maximum performance, after which their speeds decayed and the flies perished. When individual flies were exposed to 40 degrees celsius in the middle and one side tile, with the other side tile at a comfortable 22 degrees celsius the the Wild-type flies quickly stopped moving along the arena and remain in the comfortable location.
In contrast, the classic memory mutant Dunce flies keep exploring the arena and spend less time than controls in the comfortable location. Further, testing combinations of temperature and location are also useful in understanding the function of different temperature receptors during dynamic temperature changes. As illustrated in this experiment in which individual d melanogaster mutants were exposed to increasing temperatures while a shifting comfortable location at 22 degrees celsius was also provided.
While performing these procedure, remember to perform the steps in order and quickly so you can capture as much of flies behavior as possible. Next to this procedure other methods like negative geotaxis or heat choke assays can be used to answer additional questions such as where do flies move normally or have a normal heat resistance. The implications of this technique extend to us understanding neurological disorders or mutations in which temperature perception or pain play a role.
Generally, individuals new to this method will struggle because each step is simple by itself but they're required to be perfectly coordinated so the technique needs to be practiced.
View the full transcript and gain access to thousands of scientific videos
Overview
This article presents a protocol for assessing the locomotor performance of Drosophila in response to temperature changes using a programmable temperature-controlled arena. The method enables fast and accurate temperature variations, facilitating the study of flies' responses to environmental changes.
Key Study Components
Area of Science
- Neuroscience
- Behavioral Biology
- Temperature Sensitivity
Background
- Drosophila serves as a model organism for studying genetic and environmental interactions.
- Temperature changes can significantly affect locomotor activity and behavior.
- Understanding these responses can provide insights into sensory processing and adaptation.
- Automated methods enhance precision in experimental conditions.
Purpose of Study
- To investigate the locomotor performance of Drosophila at varying temperatures.
- To explore differences in responses between various genotypes.
- To analyze interactions with other sensory cues.
Methods Used
- Utilization of a programmable temperature-controlled arena.
- Placement of male and female flies in controlled environments.
- Monitoring locomotor activity under varying temperature conditions.
- Automated data collection for accurate analysis.
Main Results
- Demonstrated the ability to rapidly change temperatures and assess fly behavior.
- Identified significant differences in locomotor performance across genotypes.
- Showed interactions between temperature responses and sensory cues.
Conclusions
- This method provides a robust framework for studying temperature sensitivity in Drosophila.
- Findings contribute to understanding genetic and environmental influences on behavior.
- Future studies can leverage this technique for broader applications in neuroscience.
Frequently Asked Questions
Executive Industry Relevance
This method enables high-throughput, automated assessment of temperature-dependent locomotor performance in Drosophila, providing quantitative phenotypic data for target validation in neurogenetic studies. By capturing dynamic behavioral responses to spatially and temporally controlled thermal stimuli, it supports mechanistic de-risking of temperature-sensing pathways relevant to pain and sensory disorder models. The automated tracking and reproducible environmental control enhance predictive confidence in early discovery workflows involving gene function and environmental interaction studies.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of genetic contributions to thermal response phenotypes, supporting functional validation of temperature-sensing genes and neuronal pathways.
- Operational Value: Facilitates side-by-side comparison of mutant and wild-type strains under identical, programmable environmental conditions to isolate genotype-specific effects.
- Predictive Value: Generates dose-response-like performance curves across temperature gradients, aiding in the identification of functional thresholds and phenotypic severity gradients for target prioritization.
Screening & Assay Development
- Scientific Value: Produces quantifiable locomotor outputs (speed, location preference) that serve as robust, high-content phenotypic readouts for screening genetic libraries or pharmacological modulators of thermal sensitivity.
- Operational Value: Automated video tracking and arena standardization reduce inter-experiment variability, enabling scalable, reproducible assays suitable for medium- to high-throughput screening campaigns.
- Assay Readiness: Generates normalized behavioral metrics that can be benchmarked across genotypes and experimental batches, supporting assay validation and cross-lab reproducibility.
Translational & Preclinical Research
- Translational Relevance: Models ectotherm thermal adaptation mechanisms, offering insights into conserved neuronal thermosensation pathways with potential relevance to mammalian pain and thermoregulation targets.
- Preclinical Continuity: Enables longitudinal assessment of thermal performance curves, supporting risk-adjusted advancement decisions in target validation pipelines by establishing genotype-phenotype-environment relationships.
- Mechanistic De-risking: Allows dissection of temperature receptor function through spatial and temporal thermal profiling, reducing ambiguity in linking genetic lesions to sensory processing deficits.
Pipeline & Workflow Integration
The method fits within the early discovery continuum, linking genetic perturbation to quantifiable behavioral output in a controlled environmental context, thereby supporting hypothesis-driven target validation and lead identification efforts in neurobehavioral research.
- Discovery Biology: Supports systematic interrogation of temperature-sensing gene function by correlating genetic background with dynamic locomotor responses to controlled thermal stimuli.
- Screening: Delivers standardized, quantitative behavioral readouts (e.g., speed, spatial preference) that enable reliable compound or genotype screening in temperature-sensitive pathways.
- Analytics: Generates time- and temperature-resolved behavioral datasets suitable for statistical comparison of performance curves, EC50-like thermal thresholds, and area-under-curve metrics across experimental groups.
- Translational Research: Connects Drosophila thermal response phenotypes to conserved sensory transduction mechanisms, informing cross-species target validation in thermosensation and pain research.
- Enterprise Reuse: The automated arena and tracking pipeline represent a reusable platform for studying gene-environment interactions across multiple sensory modalities beyond thermosensation.
Operational & Enterprise Impact
- Scientific Value: Provides mechanistic clarity on temperature-sensing neural circuits by enabling precise spatiotemporal thermal challenge and automated behavioral quantification.
- Operational Value: Ensures reproducibility through standardized environmental control, automated data acquisition, and reduced manual handling, minimizing operator-dependent variability.
- Strategic Value: Improves go/no-go decision confidence by delivering objective, quantitative phenotypic data that reduces reliance on subjective behavioral scoring in neurogenetic screens.
- Portfolio Impact: Enables risk-stratified target prioritization by linking genetic lesions to measurable deficits in thermal performance, supporting early identification of high-confidence therapeutic targets.
Implementation Considerations
- Requires expertise in Drosophila handling, behavioral assay design, and video-based tracking software configuration.
- Dependent on temperature-controlled arena hardware, synchronized lighting, and video recording systems for accurate environmental and behavioral data capture.
- Necessitates cross-team standardization of arena calibration, tracking parameters, and thermal protocol definitions to ensure reproducibility across sites or users.
- Adaptation to other insect models or sensory stimuli may require recalibration of arena dimensions, tracking thresholds, and thermal ramp rates based on species-specific size and response kinetics.
- Practical limitations include arena throughput constraints (one fly per run) and the need for meticulous procedural coordination to maintain temporal alignment between thermal shifts and behavioral recording.
Biopharma FAQs
Chapters in this video
0:04
Title
0:29
Fly and Temperature-Controlled Arena Preparation
2:02
Temperature Behavioral Experiments
3:13
Video Tracking and Data Analysis
4:31
Results: Representative Drosophila Performance Analyses in Response to Temperature Changes in Space and Time
6:08
Conclusion
