Drosophila Aggression Assay: A Method to Test Behavioral Plasticity in Flies

- To assess aggression in flies, use an enclosed fighting chamber equipped with two entry points, and a divider to keep subjects separated before the trial. Place a food source in the center of the chamber to create conflict for the flies. Then, load previously isolated and marked males through the entry points on either side of the arena. Remove the divider and record the flies' encounters to quantify aggression.

To establish dominance, a male displays stereotypical offensive behaviors that increase in intensity, from approaching and chasing the opponent to lunging, a behavior that indicates aggression, where the attacking fly raises high on its hind legs and snaps down onto the opponent in an attempt to grab it. In contrast, the opponent displays defensive behaviors, like running away in retreat of the attacker. Thus, a loser and a winner emerge from the fight, and a memory of defeat or victory is formed in each opponent.

In the example protocol, we will see how a setup that eliminates animal handling during the aggression assay is used to study memory formation in flies who have lost their first fight, termed "loser" effect.

- Begin behavioral experiments by inserting plastic di