PI - Michael Rosbash, Team Leader - Jea Jung
Genetically tractable organisms like mice, fruit flies (Drosophila) and worms are frequently used to investigate the molecular and cellular mechanisms that underlie basic features of human physiology. This is because the molecules and pathways in these model organisms are similar if not identical to those of humans. These organisms are also used for practical studies, for example to help prevent disease or to develop various treatment strategies.
Drosophila is often the animal of choice. In addition to its abundant genetics tools and resources as well as the large community that has studied it for more than a century, Drosophila has a short generation time and is cheap to grow and maintain the laboratory. Surprisingly perhaps, Drosophila is also an important organism for studies focused on the brain, cognition and behavior. A good example of a Drosophila behavior that is studied all over the world is locomotor activity (movement or walking) and its accompanying sleep-wake cycles. Here too there are many similarities with humans.
The current tool to measure Drosophila locomotor activity is called the Drosophila Activity Monitor (DAM), which was invented more than 25 years ago. It is a basic “beam break device.” Single infrared beams are located in the middle of glass tubes. The beams detect the movements of individual flies whenever they cross the beam. Although this system is widely used for studying circadian rhythms and sleep in flies, it has many drawbacks and has not been updated since it was invented.
First, the DAM system is quite expensive, especially for young scientists who want to set up a new lab. Each DAM unit costs 800 dollars and only can record the activity of 32 flies. Second, the DAM system has many blind spots and is insufficiently sensitive to characterize or even detect small movements. Third, the size of the DAM system makes it inconvenient, probably impossible, to incorporate additional features such as LEDs for optogenetics or devices for sleep deprivation. In short, these drawbacks of the DAM system are a bottleneck for the broader study of Drosophila behavior.
In order to overcome these issues, my team has engineered a totally new, all-in-one system. It utilizes a high sensitivity video camera to record individual fly behavior in four 96-well plates. Our new system has therefore increased the sensitivity of the detection system as well as the throughput, in the latter case by 12 times (96X4 flies vs 32 flies). In addition, we have incorporated UV LEDs for entrainment, red LEDs for optogenetics as well as a solenoid device for arousal. All of this is built into one box, FlyBox, which sits on a bench-top. Importantly, this new system therefore bypasses the need for the expensive and space-hungry incubators into which the DAM systems normally reside.