Inheritance Pattern of Female Receptivity in Drosophila prolongata.

Choosiness, or female receptivity to copulation, is a critical component in female preference for a mating partner, as it functions at the final step in the mating process by determining whether she accepts copulation with a given male. In spite of its importance in the evolutionary process of male traits via sexual selection, little is known about the genetic variation and inheritance pattern of female receptivity. Drosophila prolongata shows a unique courtship behavior, leg vibration, which increases female receptivity to copulation. In the present study, we analyzed variation in female receptivity and its inheritance pattern in isofemale strains of D. prolongata using leg vibration as an index. There was a significant difference in female receptivity among the strains examined. A high-receptivity phenotype was semi-dominantly expressed in F1 females of crosses between strains with low and high receptivity. Backcrossing F1 females to low-receptivity strains resulted in a lower level of receptivity, suggesting that the high-receptivity phenotype is controlled by multiple genes with epistatic interactions. These results indicate a genetic basis of female receptivity, shedding light on the evolutionary process of sexual selection in D. prolongata.