Impaired courtship performance of <i>Md-tra^man</i> males.

<p>(A) Sketch of the housefly courtship ritual as described by <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062476#pone.0062476-Meffert1" target="_blank">[36]</a>: (1) The male fly (blue) approaches the female (pink) and performs an abortive form of walking and stalking towards the female. The male fly will interdigitate his legs with those of the female while making tapping movements. The female may respond with similar fencing. (2) Next the male will mount the female and flutter his wings. (3) While he is lunging forward to the head of the female he will continue to flutter. He will then lift the female’s forelegs. At this point, he holds his wings in a position that is roughly 180° from their resting orientations. (4) When mounted, the female thrusts her wings 90° to her body and perpendicular to the substrate. (5) Finally, the male will lean backward and attempt to copulate. The whole ritual lasts around 2 seconds and will be repeated by the male when the first attempt fails. (B) Courtship activity of standard wild-type XY males, <i>Md-tra^man1</i> males, and <i>Md-tra^man2</i> males in single mating assays with wild-type females; percentage of males which courted at least once during a 20 minutes observation period (total number of males per genotype observed n = 20). A marked reduction of courting activity is observed for <i>Md-tra^man1</i> males and almost no activity is seen for <i>Md-tra^man2</i> males. (C) Percentage of males performing individual steps of the courtship ritual (total number of courting males per genotype observed n = 19). While the percentage of wildtype XY males initiating courtship remains equally high throughout the various steps of the ritual, the percentage of <i>Md-tra^man</i> males engaged in courtship declines precipitously during the last steps, in particular step 3 (fluttering) and step 5 (copulation attempt).