The genetic architecture of aggressive behavior in Drosophila melanogaster. A.C. Edwards, T.F.C. Mackay. Genetics, North Carolina State Univ, Raleigh, NC.

   Behavioral research is an important component of human health studies, in that many health problems incurred are directly or indirectly related to or typified by specific behaviors. Drosophila melanogaster is a model organism for many behaviors, in part because flies can be easily manipulated for classical genetic studies and more technologically advanced approaches. In addition, many biological processes in flies are homologous to those in humans; such is the case for neurological pathways involved in behavior. Aggression is one such behavior, and an assay has been developed to quantify subtle differences in aggression among lines of flies with distinct genetic backgrounds. Using this assay, complementation tests were performed to identify candidate genes that would likely impact variation in aggression in natural populations. The serotonergic and dopaminergic pathways have been hypothesized to be involved in aggression. For this reason, complementation of the second chromosome genes Ddc, Punch, and catsup, which are involved in these pathways, has been the focus thus far. Mutations in these genes were crossed into a common inbred background. This inbred strain was also used as the control line. The mutant and control lines were then crossed to 29 wild-derived second chromosome lines, which were substituted into the same common background, to test for complementation. Two-way analysis of variance was used to partition variation in aggression between the wild-derived line, cross (mutant vs. control), and the line x cross interaction. Quantitative failure to complement was inferred if the line x cross interaction was significant (P<0.05). Current results of these analyses will be discussed.