XY males show courtship sluggishness when compared to wild type siblings, though they are generally hyperactive. Aging does not improve the courtship performance. Song pulses are similar to those of dsx+ males, though interpulse intervals are longer than for wild type in hemizygotes. Number and duration of song bouts are much reduced. No sine-song bouts whatsoever are generated by dsx mutants. In elicitation and rejection tests, dsx haplo-X mutants demonstrate an attractiveness that cannot be explained by general enfeeblement, such as inability to reject courtship advances.
XX dsx16/Df(3R)dsx15 flies do not show any male-specific courtship when paired with mature virgin females. 33% of XY dsx16/Df(3R)dsx15 flies show male-specific courtship when paired with mature virgin females.
Dorsal musculature does not undergo sexual transformation.
Duncan.
Rank order for subnormal courtship in dsx alleles is dsx1 < dsx16 < dsx15 < dsx23.