Aggressive behavior is pervasive in the animal kingdom. It is the result of interactions between stimuli from the environment and internal activity of the brain. Although aggression is influenced by the environment, genetic differences between animals also play an important role in this behavior. In this project, aggression is studied in the laboratory fruit fly, Drosophila melanogaster. Male fruit flies display obvious aggression responses in the presence of food territories and females. Even in the absence of these triggers, aggression can be observed albeit at lower frequency. The aggression responses are measured with simple and reproducible assays. Moreover, the fruit fly offers the advantage of a large number of genetic and neurobiological tools to analyze this behavior. Using these tools, the behavior will be dissected to better understand the mechanisms. Preliminary studies suggest that the basic molecular machinery regulating the drive to display aggression appears to be very similar between flies and mice. In addition, these studies also show that the neurons that regulate the behavior in the fruit fly are also surprisingly similar to neurons in mice that are known to regulate mammalian aggression. The function of the conserved machinery in these functionally similar neurons will be further studied in this series of experiments. These studies may identify a basic mechanism involved in the regulation of aggression in all animals. These studies will drive the field of study of aggression in a new direction: from a main focus on hormonal control and modulation to transcriptional control in specific neuronal targets to integrate environmental responses that result in optimal adaptive behavior. The laboratory uses state of the art technology and resources for training the next generation of scientists. The lab actively participates in the training of minority students through the SMART program and the Houston Community College Science Intern Program.