ScerGAL4^ppk25.PS transcript is detected by RLM-RACE in male prothoracic legs, but not in adult heads from which the antennae had been removed. ScerGAL4^ppk25.PS drives expression in a small subset of gustatory and olfactory receptor neurons, some of which have been implicated in male courtship behavior, and which coexpress fru. Expression is observed in a subset of neurons innervating the taste hairs of both male and female legs and wings, but in no other body parts. ScerGAL4^ppk25.PS is limited to one gustatory neuron per leg taste bristle. Expression is also observed in olfactory neurons that project from antennal segment three to antennal lobes VA1v or VL2a. Expression does not overlap with that of CheB42a protein.

ScerGAL4^ppk25.PS drives expression in one of four gustatory receptor neurons of many of the taste bristles in the male legs; expression is consistantly observed in 43 gustatory receptor neurons on the tibia and five tarsal segments. All of the prothoracic gustatory receptor neurons labelled by ScerGAL4^ppk25.PS co-express EcollexA^fru.P1. For the pairs of prothoracic neurons labelled by EcollexA^fru.P1, expression of ScerGAL4^ppk25.PS can be detected in both, or only one of the neurons. Expression of ScerGAL4^ppk25.PS and ScerGAL4^ppk25.PS is very similar: all but 11 ScerGAL4^ppk29.3.020 positive neurons, are also labelled by ScerGAL4^ppk29.3.020. In most cases, these 11 ScerGAL4^ppk29.3.020-expressing neurons are paired within a single taste hair with a neuron that expresses both ScerGAL4^ppk25.PS and ScerGAL4^ppk29.3.020. Gustatory receptor neurons in the wing margin, but not in the labellum, also express ScerGAL4^ppk25.PS. The leg and wing neurons project to each of the thoracic ganglia. The prothoracic neurons that are labelled by ScerGAL4^ppk25.PS send sexually dimorphic projections to the first thoracic ganglion: projections from males cross the midline more often than female ones.