Automated Monitoring and Analysis of Social Behavior in Drosophila

We introduce a method based on machine vision for automatically measuring aggression and courtship in Drosophila melanogaster. The genetic and neural circuit bases of these innate social behaviors are poorly understood. Highthroughput behavioral screening in this genetically tractable model organism is a potentially powerful approach, but it is currently very laborious. Our system monitors interacting pairs of flies and computes their location, orientation and wing posture. These features are used for detecting behaviors exhibited during aggression and courtship. Among these, wing threat, lunging and tussling are specific to aggression; circling, wing extension (courtship ‘song’) and copulation are specific to courtship; locomotion and chasing are common to both. Ethograms may be constructed automatically from these measurements, saving considerable time and effort. This technology should enable large-scale screens for genes and neural circuits controlling courtship and aggression. How are innate behaviors programmed into the genome? Answering this question requires identifying the genes that control specific behaviors, the neural circuitry on which they act, and how this circuitry controls behavior 1‐5 . This may be attempted in model organisms such as the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster, thanks to the abundant genetic tools for marking, mapping and manipulating specific populations of neurons 6,7 , thereby enabling large-scale genetic and functional screens 8,9 .