Transcriptional activator which promotes male-specific development (PubMed:18550714, PubMed:28065609). Acts partially redundantly with the transcription factor mab-3 to coordinate tail tip cell fusion and retraction and thereby regulate male tail tip morphogenesis (PubMed:18550714, PubMed:30910805). This is most likely through the regulation of downstream effectors such as eff-1 (PubMed:18550714). May also negatively regulate the expression of other proteins implicated in male tail morphogenesis including nhr-25, vav-1 and arl-1 in tail tip cells (PubMed:21408209). In males, plays a role in the development of ray A-neurons by negatively regulating the activity of the transcription factor ast-1 (PubMed:22069471). Plays a role in the male-specific differentiation of PHC sensory neurons into densely connected hub sensory neurons (PubMed:28065609). Plays a role in male mating behavior (PubMed:22069471). In males, expressed in the tail tip (PubMed:18550714, PubMed:21408209, PubMed:22069471, PubMed:30910805). Specifically, expressed in 15 male-specific muscles of the tail tip called the diagonal muscles, and also in core body muscles of both males and hermaphrodites (PubMed:22069471). In males, expressed in ray A-neurons (PubMed:18550714, PubMed:22069471). In males, expressed in PHC sensory neurons (PubMed:28065609). In males, it is also expressed in the hindgut, B lineage and somatic gonad (PubMed:18550714). In hermaphrodites, expressed in the anchor cell only (PubMed:18550714). Expressed in cells of the male tail tip from the L3 larval stage. Expression peaks during male tail tip retraction and decreases rapidly upon completion (PubMed:18550714). Not expressed in cells of the hermaphrodite tail tip at any developmental stage (PubMed:18550714). Negatively regulated by lin-41 which causes degradation of the mRNA encoding this protein. RNAi-mediated knockdown results in male tail morphology defects. Belongs to the DMRT family.