Member of the regulatory pathway controlling female somatic sexual differentiation, regulated by Sxl. Activates dsx female-specific splicing by promoting the formation of a splicing enhancer complex which consists of tra, tra2 and sr proteins. Speckled subnuclear compartment. RS domain directs localization of proteins to the speckled subnuclear compartment and the purpose of this localization is to allow colocalization and co-concentration of components of the splicing and splicing regulatory machinery to permit relatively high rates and/or efficiencies of reaction and interaction. The sexual regulation of tra occurs through a mechanism of sex-specific alternative RNA splicing. The non-sex-specific RNA expressed in males is not translated. It is uncertain whether Met-1 or Met-3 is the initiator.