Probable transcription factor that plays a role in the development of the dopaminergic neurons of the male-specific genital sensilla (simple sense organs) known as rays, by negatively regulating the activity of the transcription factor ast-1 (PubMed:22069471, PubMed:12231628). Involved in male mating behavior, probably as a result of a role in the differentiation of male-specific diagonal muscles (PubMed:12231628, PubMed:22069471). Required for development of the male proctodeum (PubMed:12231628). May be dispensable in hermaphrodites (PubMed:12231628). Expressed in a limited number of non-sex-specific tissues in males, including 6-8 unidentified neurons of the head, ventral body wall muscle, and the PHCL/R neurons. In males, expressed in several sex-specific cell types during larval development and in the adult, including the A-type ray sensory neurons, ventral male-specific muscles, and unidentified neurons of the male posterior ventral nerve cord (PubMed:12231628). Transiently expressed during larval development in the hindgut (PubMed:12231628). RNAi-mediated knockdown causes defects in patterning of the dopaminergic neurons of the male-specific genital sensilla (simple sense organs) known as rays (PubMed:12231628). Males are unable to sire progeny due to abnormal tail and gonad morphology, whereas hermaphrodites have no obvious phenotypic defects (PubMed:12231628).