Fighting Flies

Most laboratory strains of D. melanogaster rapidly lose the aggressiveness that is common to strains in the wild, suggesting that aggressive behavior might be recoverable in laboratory strains by deliberately selecting for it. Dierick and Greenspan devised a new 'two-male arena assay', in which twenty pairs of males were placed in a chamber containing separate arenas, and assessed for several parameters related to aggression, including the frequency, intensity, and total amount of time spent fighting (see video and still image). More aggressive males were then selected and mated to random females, a procedure which was repeated for more than twenty generations. Flies in the final generation were thirty times as aggressive as those in the first generation.

The authors report that approximately eighty genes were significantly differentially expressed between the more aggressive and less aggressive flies. One of the genes, Cyp6a20, when mutated, alone had a significant effect on aggressive behavior. Although it is not yet possible to generalize from these preliminary data, the assay and approach used should set a new standard for the genetic analysis of aggressive behavior.

Author contact:

Ralph Greenspan (The Neurosciences Institute, San Diego, USA)
E-mail: greenspan@nsi.edu

Abstract available online.

(C) Nature Genetics press release.

Message posted by: Trevor M. D'Souza