Courtship behavior and control of reproductive isolation in Drosophila mojavensis: genetic analysis of population hybrids.

Drosophila mojavensis from the Sonora region and Baja California show asymmetrical sexual isolation in the laboratory: males from Sonora mate equally frequently with Sonora and Baja females, while the mating success of Baja males with Sonora females is reduced. This failure has been localized to three separate behavioral landmarks occurring during courtship. Genetic analysis was conducted using reciprocal F1 hybrids of Sonora and Baja strains to examine inheritance patterns of the responsible courtship behaviors. Mating success and propensity of F1 males were similar to Sonora males. F1 females mated with males of Sonora and Baja races equally, although mating propensity of F1 females was intermediate between that of Sonora and Baja females. Males of Baja strains presented with F1 females showed a relatively high level of failure at attempted intromission. Genes for mating behaviors are located in the autosomes, but different loci responsible for the sexual isolation appear to act in males and females.