Copulation typically lasts ∼20 min (Jagadeeshan and Singh, 2006). For the first several minutes of this period, wild-type pairs may move forward or adjust positions, but for the remainder of this time the flies remain essentially motionless. Copulation in prt1 mutants differs dramatically. Similar to wild-type flies, prt1 males mount the female and curl their abdomen to begin copulation. However, after coupling, the

prt1 male continuously struggles to maintain his orientation and can be seen in a variety of different positions relative to the female ( Figure 6B, bottom pictures; Movie S2). We quantified the amount of time that prt1 http://www.selleckchem.com/products/GDC-0449.html males spent in a position distinct from that usually seen in wild-type flies as a percentage of the total copulation duration ( Figure 6C). Whereas CS flies primarily remain centered on the dorsal abdomen of the female, prt1 flies spent nearly half of copulation severely misaligned. Although the genitalia of the male and female remain in contact, the male can be positioned perpendicular AZD8055 to the normal

axis or rotated nearly 180° from horizontal. Moreover, during copulation, prt1 mating pairs move about the observation chamber, with the female dragging the male behind. In cross-genotype mating experiments, prt1 males mated to CS females showed defective copulation, whereas CS males mated to prt1 females did not ( Figure 6C). Thus, the prt1 males were primarily, if not exclusively, responsible for the defect in copulation. To determine whether the change in the males’ position was due to a defect in genital morphology, we examined both the prt1 male and female genitalia using scanning electron microscopy. We found that the external genitalia of prt1 males and females were indistinguishable from wild-type ( Figures S3D and S3E). We also examined the prt1 males’ sex combs, specialized foreleg structures used to grasp the female

during copulation ( Ahuja and Singh, 2008 and Ng and Kopp, and 2008). The morphology of prt1 sex combs was intact in scanning electron micrographs ( Figure S3F), without obvious gaps between bristles, although the number of bristles in the prt1 sex combs was slightly lower than controls ( Figure S3G; Ahuja and Singh, 2008 and Tokunaga, 1961). We employed deficiency analysis to help determine the severity of the prt1 sexual phenotype ( Figure 6D). Two deficiency lines that uncover the prt locus were used, and the extent of their chromosomal deletions is represented in Figure 4A. The copulatory phenotype seen in the prt1 homozygote was replicated in both the prt1/Df(3R)mbc-30 and prt1/Df(3R)Exel6195 transheterozygotes ( Figure 6D). It is possible that the prt1 copulation phenotype cannot get measurably worse, and further deficiency analysis using other aspects of the prt1 phenotype will be necessary to more precisely assess the severity of the prt1 allele.