ScerGAL4^4-57 drives expression in a subset of fru positive neurons in males; 2 aDT-h neurons, 2-3 aSG5 or aSG6 neurons, ~4 elsewhere within the adult subesophageal zone - divided into two distinct clusters, 2 neurons within the prothoracic neuromere, 2 neurons at the boundary between the prothoracic and mesothoracic neuromeres and 2 neurons within the adult abdominal neuromere. Variable expression between flies was also seen in 1-2 aSP3 neurons and a neuron within the prothoracic neuromere distinct from those described above. In male brains, adult fruitless aDT-h neurons were seen as a single soma in the periphery of the median bundle, projections from which branched out into the region proximal to the esophagus and dorsal to the tritocerebrum and continued to the superior medial protocerebrum. Also, in male brains, some aSG5/6 neurons have extensive arborisation throughout the adult subesophageal zone with a collateral branching into a region, formerly known as the inferior lateral protocerebrum, encompassing part of the superior clamp and the superior lateral protocerebrum. 2 fru positive neurons in the adult subesophageal zone described above, have bilateral projections towards the tritocerebrum and two descending tracts into the thoracico-abdominal ganglion. These exhibit sexual dimorphism, having reduced aborization in female brains compared to males. The presynaptic marker nSyb^{FRT.UAS.cYa.GFP} is expressed mainly in the prothoracic/metathoracic boundary region, while the somatodendritic Dscam1^{FRT.17.1.UAS.EGFP} marker was detected in the tritocerebral and the two descending tracts.