Isolation of Aggressive Behavior Mutants in <i>Drosophila</i> Using a Screen for Wing Damage

Abstract

Aggression is a complex social behavior that is widespread in nature. To date, only a limited number of genes that affect aggression have been identified, in large part because the complexity of the phenotype makes screening difficult and time-consuming regardless of the species that is studied. We discovered that aggressive group-housed <i>Drosophila melanogaster</i> males inflict damage on each other's wings, and show that wing damage negatively affects their ability to fly and mate. Using this wing-damage phenotype, we screened males from ∼1400 chemically mutagenized strains and found ∼40 mutant strains with substantial wing damage. Five of these mutants also had increased aggressive behavior. To identify the causal mutation in one of our top aggressive strains, we used whole-genome sequencing and genomic duplication rescue strategies. We identified a novel mutation in the voltage-gated potassium channel <i>Shaker</i> (<i>Sh</i>) and show that a nearby previously identified <i>Sh</i> mutation also results in increased aggression. This simple screen can be used to dissect the molecular mechanisms underlying aggression.