Loyal or promiscuous: A search for female mate preference in Drosophila melanogaster

Abstract

In Drosophila, females are generally known to be promiscuous. Several studies suggest that the phenomenon of polyandry has a selection advantage caused by stress conditions induced by sex-linked meiotic drive and other selfish sex ratiodistorting elements during evolution. In contrast, females are known to recognize and mate with conspecific males from amongst members of different species and races. In this study, assuming a genetic basis for mate preference, using selection studies, we tried to amplify the percentage of monandrous females and establish two separate lines of females that chose to remate with the same male and those that do not. We selected the females which did, or did not, prefer to mate with the same male, for two generations. We then allowed these selected females to inbreed for three more generations and found that though there was an increase in the frequency (from 0.35 to 0.55) of females choosing to remate with the same male in the fifth generation as compared to first generation, no significant difference in the mate preference by females in the fifth generation between the two selected lines was observed. These findings suggest that the selection experiments need to be performed on a greater number of generations to get conclusive results or that there may be no genetic basis for loyalty in females for mate choice in Drosophila melanogaster.