The mating behavior of Drosophila melanogaster is a stereotyped sequence of fixed action patterns, composed of orientation, tapping, singing, licking, attempted copulation and copulation. Mutations that block a unique aspect of mating behavior were isolated and analyzed at the cellular and molecular levels. The wild-type counterparts of the mutated genes were shown to rescue the phenotypes by their ubiquitous or targeted expression in some of the mutants. This strategy of artificial control of fly behavior opens up an avenue for studies to identify the neural center for individual behavioral actions.