Abstract
The control of courtship song inDrosophila melanogaster was mapped to the central nervous system using sex mosaics. Some male-female mosaics follow females and extend their wings at them. This behavior is associated with male brain tissue. Only about two-thirds of the courting mosaics have a normal pulse song when courting; the rest produces abnormal sonic output when extending and vibrating their wings, or no sound at all. Normal pulse song is most closely associated with male genotype in the ventral thoracic ganglia. The substructure in these ganglia closest to the tentative focus is the ventral mesothoracic neuromere. This focus for pulse song is domineering, in that male tissue in either the left or right ganglion is sufficient for normal singing by both the left and right wing. Sine song was produced by only some of the mosaics with normal pulse song. Mapping of the sine song did not lead to a definitive focus, but the genotype of particular regions of the brain and thoracic ganglia tend to be associated with production of sine song.