Building a better mousetrap: High-throughput, high-parameter analysis of Drosophila aggression gives novel insight into the genetic architecture of behavior. Bryn E. Gaertner, Landon Blakey, Kirsty Ward, Trudy F. C. Mackay. Genetics, North Carolina State University, Raleigh, NC.

   Aggression, a physical confrontation resulting from disputes over territory or resources, is ubiquitous in the animal kingdom. Beneath this broad definition, individuals within and between species vary remarkably with respect to the circumstances and persistence of aggression, resulting in natural variation from passive and permissive to overt antagonism. Such is the case in a wild-derived genetic reference panel of Drosophila melanogaster, where in stressful (food deprived) conditions, inbred lines vary from almost no aggression to more than one aggressive encounter every second. Attempting to map the genetic basis to this trait has proven difficult, as epistasis is pervasive and a statistical signal may be lost because the term aggression covers many different behaviors, each of which may have its own unique genetic architecture. To address these issues, we have set out to build a novel experimental regime that allows for high-throughput recording of pairs of Drosophila males. These videos are subsequently analyzed for all described aggression subtypes, such as wing-flicking, boxing, kicking, and chasing. Using this approach, we have identified important differences in behavioral subtypes among inbred lines as well as their hybrid progeny. Because of the high-parameter method of phenotyping, we can then map the genetic basis of these differences to a handful of candidate genes.